  Builtin Tela functions
  Pekka	Janhunen, Pekka.Janhunen@fmi.fi
  Version 1.2, Wed Jan 18 10:01:27 EET 1995

  This document	has been automatically generated from the online help
  messages of builtin Tela functions.

  1.  INTRODUCTION

  Negative error codes describe	fatal errors, whereas positive error
  codes	are warnings only. In case of fatal error, the function	output
  arguments have undefined values. If a	function has no	output
  arguments, it	typically has only positive return codes.

  The error code descriptions do normally not appear in	the Tela help
  messages. If an error	occurs,	Tela will however find and display the
  proper textual message.


  1.1.	BatchMode



       [y] = BatchMode()
	BatchMode() returns 1 if this Tela process is in batch mode
	  (command line	switch -b), otherwise 0.


       See also: ``SilentMode'', ``VerboseMode''.



  1.2.	CheckReadOnlyMode



       [y] = CheckReadOnlyMode(;x)
	CheckReadOnlyMode() returns 1 if this Tela process checks that function
	  input	arguments are not modified by the function. The	check is done by
	  default, but if it causes problems (bugs in Tela) you	can turn it off
	  using	CheckReadOnlyMode(off).
	  CheckReadOnlyMode returns the	old mode setting.


       See also: ``SilentMode'', ``BatchMode'',	``VerboseMode''.

	  Error	codes:
	  1: Argument not integer





  1.3.	FFT












  [f] =	FFT(u; dim)
   FFT(u) gives	the complex Fast Fourier Transform of u.
     If	u's rank is more than one, the transform is computed
     only along	the first dimension (many independent 1D
     transforms).

     FFT(u,dim)	computes the FFT along the specified dimension.
     The first dimension is labeled 1 and so on.

     For vector	u, f=FFT(u) is equivalent with

     n = length(u); f =	czeros(n);
     for (j=1; j<=n; j++)
	 f[j] =	sum(u*exp(-(j-1)*(0:n-1)*2i*pi/n));

     All Fourier transform functions in	Tela can take the transform
     along any dimension in a multidimensional array, and the transform
     length is not restricted. The function FFT	should be used only in
     case of complex input data. Use realFFT for real input array.

     Functions FFT, realFFT, sinqFFT, cosFFT and their inverses
     are the most efficient when the transform length n	is a product
     of	small primes.

     Functions sinFFT and invsinFFT are	efficient when n+1 is
     a product of small	primes

     Functions cosFFT and invcosFFT are	efficient when n-1 is
     a product of small	primes



  See also: ``invFFT'',	``realFFT'', ``sinFFT'', ``cosFFT'', ``sin-
  qFFT'', ``cosqFFT''.

     Error codes:
     -1: First argument	not a numeric array
     -2: Second	argument not integer
     -3: Second	argument out of	range






  1.4.	GetInstructionData



       [Ninstructions,Noperations] = GetInstructionData(p,mnemo)
	[Ninstr,Nops] =	GetInstructionData(p,"mnemonic") returns
	  the number of	specific instructions executed when p=perf() was
	  gathered, and	the number of (floating	point) operations associated
	  with the instruction.
	  The mnemonic must be a string, and it	may be any of the names
	  that appear in the disasm(f) listing.	In addition, mnemonic may
	  be "flop", which includes all	instructions that may perform floating
	  point	arithmetic, or it may be "*", which includes all instructions.
	  Error	codes:
	  -1: Bad first	argument, must be obtained from	perf()
	  -2: Second arg not a string
	  -3: Second arg not a recognized string




  1.5.	HeavisideTheta



       [y] = HeavisideTheta(x)
	y = HeavisideTheta(x) returns 1	if x>=0	and 0 if x<0.
	  x must be real. If x is array, the operation is applied componentwise.


       See also: ``sign''.

	  Error	codes:
	  -1: Complex or nonnumeric input argument





  1.6.	Im



       [y] = Im(x)
	y = Im(x) computes the imaginary part of a complex quantity x.
	  If x is real or integer, the result is zero.
	  If x is an array, the	operation is applied componentwise.


       See also: ``Re'', ``conj'', ``arg''.

	  Error	codes:
	  -1: Nonnumeric input argument





  1.7.	LU



       [L;U,P] = LU(A)
	[L,U,P]	= LU(A)	computes the LU	factorization of matrix	A.
	  The factorization is A = P**L**U, where P is a permutation
	  matrix, L is lower triangular	with unit diagonal and U is
	  upper	triangular.
	  [lu] = LU(A) leaves the factors L and	U packed in one	matrix.
	  [lu,p] = LU(A) returns also the pivoting info	vector p.
	  (Notice that this p is related to the	permutation matrix P
	  but is not the same. You need	this form of LU	if you want to
	  use LUbacksubst later	on.)


       See also: ``LUbacksubst'', ``linsolve'',	``inv'', ``chol'', ``SVD''.

	  Error	codes:
	  1: Singular matrix (==> zero in U's diagonal)
	  -1: Input arg	not an array
	  -2: Input arg	not a rank-2 array (matrix)







  1.8.	LUbacksubst



       [x] = LUbacksubst(lu,p,b)
	LUbacksubst(lu,p,b) solves the linear system A**x == b,
	  where	A has been previously LU-decomposed using LU:
	  [lu,p] = LU(A).


       See also: ``linsolve'', ``LU''.

	  Error	codes:
	  -1: First input arg is not an	array
	  -2: First input arg is not a square matrix
	  -3: Second input arg is not an integer vector
	  -4: Third input arg is not an	array
	  -5: Third input arg is not a vector or matrix
	  -6: Incompatible dimensions in first/third args
	  -7: Singular matrix
	  -8: Incompatible dimensions in first/second args
	  -9: Internal error





  1.9.	Re



       [y] = Re(x)
	y = Re(x) computes the real part of a complex quantity x.
	  If x is real or integer, it is returned as such.
	  If x is an array, the	operation is applied componentwise.


       See also: ``Im'', ``conj'', ``arg''.

	  Error	codes:
	  -1: Nonnumeric input argument





  1.10.	 SVD



       [U;S,V] = SVD(A)
	[U,S,V]	= SVD(A) computes the singular value
	  decomposition	of matrix A: A = U**S**V'.
	  U and	V are unitary and S is diagonal.
	  SVD(A) as such returns the vector of singular	values.


       See also: ``LU'', ``chol''.








     Error codes:
     1:	No convergence
     -1: Input arg not an array
     -2: Input array is	not a matrix
     -3: Internal error
     -4: Two output arg	case not supported (must be 1 or 3)






  1.11.	 SilentMode



       [y] = SilentMode()
	SilentMode() returns 1 if this Tela process is in silent mode
	  (command line	switch -s), otherwise 0.


       See also: ``BatchMode'',	``VerboseMode'', ``CheckReadOnlyMode''.



  1.12.	 T87



       [Bx,By,Bz] = T87(Kp,x,y,z)
	[Bx,By,Bz] = T87(Kp,x,y,z) computes the	Tsyganenko-87 model
	  magnetic field. The non-truncated version of the model is used.
	  Inputs: Kp, the Kp index; x,y,z, GSM coordinates
	  in Earth radii. Outputs: total magnetic field	in nanotesla in
	  GSM coordinates.


       See also: ``T89'', ``m2i'', ``geotomag''.

	  Error	codes:
	  -1: Bad type of input	arg





  1.13.	 T89



       [Bx,By,Bz] = T89(Kp,x,y,z)
	[Bx,By,Bz] = T89(Kp,x,y,z) computes the	Tsyganenko-89 model
	  magnetic field. Inputs: Kp, the Kp index; x,y,z, GSM coordinates
	  in Earth radii. Outputs: total magnetic field	in nanotesla in
	  GSM coordinates.


       See also: ``T87'', ``m2i'', ``geotomag''.

	  Error	codes:
	  -1: Bad type of input	arg





  1.14.	 VerboseMode



       [y] = VerboseMode(;x)
	VerboseMode() returns 1	if this	Tela process is	in verbose mode
	  (command line	switch -v), otherwise 0.
	  VerboseMode(on) and VerboseMode(off) set the verbose mode on
	  and off, respectively. They return the old mode setting.


       See also: ``SilentMode'', ``BatchMode''.

	  Error	codes:
	  1: Argument not integer





  1.15.	 abs2



       [y] = abs2(x)
	y = abs2(x) computes the square	of the absolute	value of x.
	  If x is real or integer, the result is just the square of x.
	  If x is complex, the result is equal to x*conj(x).
	  If x is an array, the	operation is applied componentwise.
	  Error	codes:
	  -1: Nonnumeric input argument





  1.16.	 acos



       [y] = acos(x)
	y = acos(x) computes the arc cosine of x.
	  If x is complex, the result is complex, otherwise real.
	  If x is an array, the	operation is applied componentwise.





  1.17.	 all



       [y] = all(x)
	all(x) returns 1 if all	elements of x are nonzero,
	  and 0	otherwise.
	  x must be an integer array or	scalar.


       See also: ``any''.

	  Error	codes:
	  1: Argument not integer or IntArray



  1.18.	 annotate



       [] = annotate(primitive...)
	annotate("primitive"[,options])	adds MTV annotations to	the previous
	  graph. The plot command(s) and the annotate command(s) must appear
	  inside hold(on) ... hold(off)	in order to work correctly.


       See also: ``plotopt'', ``hold'',	``plot'', ``pcolor'', ``mesh'',
       ``contour'', ``vplot''.

	  Error	codes:
	  1: Could not open temporary MTV file
	  2: First argument not	a string
	  3: Syntax error in graph options





  1.19.	 any



       [y] = any(x)
	any(x) returns 1 if at least one element of x is nonzero,
	  and 0	otherwise.
	  x must be a integer array or scalar.


       See also: ``all''.

	  Error	codes:
	  1: Argument not integer or IntArray





  1.20.	 arg



       [phi] = arg(z)
	arg(z) returns the argument of a complex quantity
	  (in radians).	The result is between -pi and pi.
	  If z is a complex array, the operation is applied
	  componentwise.


       See also: ``Re'', ``Im'', ``conj''.

	  Error	codes:
	  -1: Argument has undefined value
	  1: Nonnumeric	argument





  1.21.	 asin



  [y] =	asin(x)
   y = asin(x) computes	the arc	sine of	x.
     If	x is complex, the result is complex, otherwise real.
     If	x is an	array, the operation is	applied	componentwise.





  1.22.	 atan



       [y] = atan(x)
	y = atan(x) computes the arc tangent of	x.
	  If x is complex, the result is complex, otherwise real.
	  If x is an array, the	operation is applied componentwise.


       See also: ``atan2''.



  1.23.	 atan2



       [z] = atan2(y,x)
	z = atan2(y,x) computes	the arcus tangent of y/x using the signs
	  of both arguments to determine the quadrant of the return value.
	  The input argument must be integer or	real scalars and the
	  return value is real.


       See also: ``atan''.

	  Error	codes:
	  -1: Bad input	argument





  1.24.	 autoglobal



       [y] = autoglobal(...)
	autoglobal("sym1","sym2",...) sets the 'autoglobal' attribute
	  to given symbols. The	symbols	are then globally accessible
	  from inside packages and functions without need to explicitly
	  declaring them global. Constants such	as pi carry the	autoglobal
	  attribute automatically, but with this function it is	possible
	  for the user to define more autoglobal symbols.

	  Warning: This	function is for	experts	only. It is not	advisable
	  to say autoglobal("x"), for instance,	because	many existing code
	  may then break down.


       See also: ``hide''.

	  Error	codes:
	  1: Argument not a string


  1.25.	 autosource



       [] = autosource(fn...)
	autosource("file.t","name1","name2",...) tags symbols
	  name1, name2,... such	that the command source("file.t")
	  is effectively executed when any of the symbols name
	  is used. This	is load-on-demand.


       See also: ``source''.

	  Error	codes:
	  1: Argument not a string





  1.26.	 bar



       [] = bar(x,y,z...)
	bar(grouplabels,data,barnames[,options]) produces a bar	chart.
	  Example 1:

	      bar(strmat("DEC","HP"),#(111,150.6),"Speed")


       See also: ``plot'', ``hist''.

	  Error	codes:
	  1: First argument not	int nor	real array
	  2: First argument not	a vector nor matrix
	  3: Second argument not int nor real array
	  4: Second argument not a vector nor matrix
	  5: Dimension mismatch	between	first and second arg
	  6: If	second arg is vector, third arg	must be	a string
	  7: Third arg must be a string	or a string matrix
	  8: If	second arg is matrix, third arg	must be	a string matrix
	  9: Dimension mismatch	between	second and third arg
	  10: Syntax error in graph options
	  11: First arg	must not be real matrix
	  12: Could not	open temporary MTV file






  1.27.	 cd



       [] = cd(fn)
	cd("pathname") will change the current directory to "pathname".
	  Error	codes:
	  1: Input argument not	a string or a char
	  2: Directory not found





  1.28.	 ceil



       [y] = ceil(x)
	ceil(x)	returns	the smallest integer which is larger than x.
	  x must be integer or real scalar or array. If	it is an array,
	  the operation	is applied componentwise.


       See also: ``floor''.

	  Error	codes:
	  -1: Complex or nonnumeric input argument





  1.29.	 chol



       [B] = chol(A)
	B=chol(A) returns the Cholesky decomposition of	a
	  positive definite square matrix A: B'**B == A.
	  A may	be integer, real or complex valued.
	  Only the upper half of A is referenced, the lower half
	  is assumed to	be Hermitian symmetric.


       See also: ``linsolve'', ``LU'', ``matprod'', ``det'', ``eig'',
       ``inv''.

	  Error	codes:
	  -1: Input arg	is not a matrix
	  -2: Input matrix is not square
	  -3: Input matrix is not positive definite





  1.30.	 conj



       [y] = conj(x)
	y = conj(x) computes the complex conjugate of x.
	  Real and integer arguments are returned as such.
	  If x is an array, the	operation is applied componentwise.


       See also: ``Re'', ``Im'', ``arg''.



  1.31.	 contour



       [] = contour(z...)
	contour(z[,options]) plots the matrix z	as a filled contour plot.



  See also: ``contour3'', ``annotate'',	``plot'', ``mesh'', ``pcolor'',
  ``vplot''.

     Error codes:
     1:	Could not open temporary MTV file
     2:	First argument is not a	numeric	2D array
     3:	Syntax error in	graph options
     4:	Write error in MTV file	- file system full?





  1.32.	 contour3



       [] = contour3(z...)
	contour3(z[,options]) plots the	3D array as a
	  "volume" plot. Currently this	only means that	all
	  six faces of the volume are contoured	and colored
	  according to options.


       See also: ``annotate'', ``plot'', ``mesh'', ``pcolor'', ``vplot''.

	  contour.
	  Error	codes:
	  1: Could not open temporary MTV file
	  2: First argument is not a real 3D array
	  3: Syntax error in graph options
	  4: Write error in MTV	file - file system full?





  1.33.	 cos



       [y] = cos(x)
	y = cos(x) computes the	cosine function	of x.
	  If x is complex, the result is complex, otherwise real.
	  The argument must be in radians.
	  If x is an array, the	operation is applied componentwise.





  1.34.	 cosFFT














  [f] =	cosFFT(u; dim)
   cosFFT(u) gives the cosine Fast Fourier Transform of	array u.
     If	u's rank is more than one, the transform is computed
     only along	the first dimension (many independent 1D
     transforms).

     cosFFT(u,dim) computes the	FFT along the specified	dimension.
     The first dimension is labeled 1 and so on.

     For vector	u, f=cosFFT(u) is equivalent with

     n = length(u); f =	zeros(n);
     for (j=1; j<=n; j++)
	 f[j] =	u[1] - (-1)^j*u[n] + 2*sum(u[2:n-1]*cos((1:n-2)*(j-1)*pi/(n-1)));

     Note that cosFFT is most efficient	when n-1 is a product of small
     primes, where n is	the transform length.



  See also: ``invcosFFT'', ``sinFFT'', ``cosqFFT'', ``sinqFFT'',
  ``realFFT'', ``FFT''.

     Error codes:
     -1: First argument	not a real array
     -2: Second	argument not integer
     -3: Second	argument out of	range






  1.35.	 cosh



       [y] = cosh(x)
	y = cosh(x) computes the hyperbolic cosine function of x.
	  If x is complex, the result is complex, otherwise real.
	  If x is an array, the	operation is applied componentwise.





  1.36.	 cosqFFT



       [f] = cosqFFT(u;	dim)
	cosqFFT	computes the quarter-wave cosine Fourier transform.
	  Except for the quarter-wave cosine character,	it works similarly to cosFFT.

	  For vector u,	f=cosqFFT(u) is	equivalent with

	  n = length(u); f = zeros(n);
	  for (j=1; j<=n; j++)
	      f[j] = u[1] + 2*sum(u[2:n]*cos((2*j-1)*(1:n-1)*pi/(2*n)));

	  cosqFFT is most efficient when the transform length is a product
	  of small primes.




  See also: ``invcosqFFT'', ``realFFT'', ``sinqFFT'', ``FFT''.

     Error codes:
     -1: First argument	not a real array
     -2: Second	argument not integer
     -3: Second	argument out of	range






  1.37.	 cot



       [y] = cot(x)
	y = cot(x) is the cotangent function
	  cot(x) = 1/tan(x) = cos(x)/sin(x).





  1.38.	 cputime



       [t] = cputime(;p)
	cputime() returns the CPU time in seconds used by the current
	  tela session.	cputime(p) returns CPU time from performance data
	  array	p, previously obtained from perf().


       See also: ``tic'', ``toc'', ``perf''.

	  Error	codes:
	  -1: Bad argument, must be obtained from perf()





  1.39.	 csc



       [y] = csc(x)
	y = csc(x) is the cosecant function
	  csc(x) = 1/sin(x).





  1.40.	 cumprod



       [y] = cumprod(x)
	y = cumprod(x) forms an	array of partial products
	  y = #(x[1],x[1]*x[2],...,prod(x[1:n]),...).
	  The result y has the same size and type as x.	Unlike
	  prod,	cumprod	does not try to	avoid integer overflows.
	  If x is scalar, it is	returned as such.

  See also: ``prod'', ``cumsum'', ``map''.

     Error codes:
     -1: Nonnumeric input arg





  1.41.	 cumsum



       [y] = cumsum(x)
	y = cumsum(x) forms an array of	partial	sums
	  y = #(x[1],x[1]+x[2],...,sum(x[1:n]),...).
	  The result y has the same size and type as x.
	  If x is scalar, it is	returned as such.


       See also: ``sum'', ``cumprod'', ``map''.

	  Error	codes:
	  -1: Nonnumeric input arg





  1.42.	 det



       [d] = det(A)
	det(A) returns the determinant of a square matrix A.
	  A may	be integer, real or complex valued.
	  If A is scalar, it is	returned as such.
	  Error	codes:
	  -1: Nonnumeric input arg
	  -2: Input array is not a matrix
	  -3: Input matrix is not square
	  -4: Singular matrix





  1.43.	 diag



       [y] = diag(x)
	diag(V)	(V is a	vector)	returns	a square diagonal matrix,
	  whose	diagonal elements are given by V.
	  diag(M) (M is	a matrix) returns the main diagonal of M
	  as a vector.
	  Error	codes:
	  -1: Input array not vector or	matrix








  1.44.	 disasm



       [] = disasm(fn)
	disasm(f) produces disassembly listing of function f.
	  Error	codes:
	  1: Argument not a Tela function





  1.45.	 dump



       [] = dump()
	dump() dumps the stack.	Useful for debugging only.





  1.46.	 ecctogeo



       [lat,longit] = ecctogeo(latmag,longmag)
	[lat,long] = ecctogeo(latecc,longecc) transforms eccentric
	  geomagnetic latitude and longitude to	geographic latitude and	longitude.
	  All angles in	degrees.


       See also: ``geotoecc'', ``ecctogeoXYZ'',	``geotomag'', ``magtogeo''.

	  Error	codes:
	  -1: Bad first	arg
	  -2: Bad second arg






  1.47.	 ecctogeoXYZ



       [x1,y1,z1] = ecctogeoXYZ(x,y,z)
	[x1,y1,z1] = ecctogeoXYZ(x,y,z)	transforms eccentric dipole
	  point	(x,y,z)	to geographic coordinates (x1,y1,z1).


       See also: ``ecctogeo'', ``geotoeccXYZ'',	``magtogeoXYZ''.

	  Error	codes:
	  -1: Bad first	arg
	  -2: Bad second arg
	  -3: Bad third	arg






  1.48.	 echo



       [] = echo(x)
	echo(on) and echo(off) set the echo mode on and	off.
	  The mode is off by default. When echo	mode is	on, the	source
	  code is echoed as it is parsed.

	  *** NOTE: Currently this function has	no effect! ***

	  Error	codes:
	  1: Input argument not	an integer





  1.49.	 eig



       [D;V] = eig(A)
	eig(A) returns the eigenvalues of a square matrix A.
	  [D,V]	= eig(A) returns the eigenvalues in D and the
	  right	eigenvectors as	columns	of V. The eigenvectors
	  satisfy A**V == D*V.


       See also: ``inv'', ``LU''.

	  Error	codes:
	  1: Failed to converge
	  -1: Input arg	is not an array
	  -2: Input array is not a matrix
	  -3: Input matrix is not square
	  -4: Internal error






  1.50.	 eval



       [] = eval(s)
	eval("string") executes	string as a Tela command, as it	had been
	  typed	from the keyboard.
	  The evaluation is done in global context. The	symbols	appearing
	  in the string	refer to the global ones.


       See also: ``evalexpr''.

	  Error	codes:
	  1: Argument not a string or char








  1.51.	 evalexpr



       [y] = evalexpr(s)
	evalexpr("expression") executes	string as a Tela command,
	  returning its	value in y.
	  The evaluation is done in global context. The	symbols	appearing
	  in the string	refer to the global ones.


       See also: ``eval''.

	  Error	codes:
	  1: Argument not a string or char





  1.52.	 exit



       [] = exit()
	exit() stops Tela. quit() is synonym for exit().





  1.53.	 exp



       [y] = exp(x)
	y = exp(x) computes the	exponent function of x.
	  If x is complex, the result is complex, otherwise real.
	  If x is an array, the	operation is applied componentwise.





  1.54.	 export_RIS8



       [] = export_RIS8(fn,x)
	export_RIS8("file.hdf",x) writes (appends) integer matrix x
	  to HDF file "file.hdf" as a raster-8 image (Raster Image Set,	RIS).
	  When the file	is opened with default settings	using the usual
	  HDF viewers such as Spyglass products, the first dimension grows
	  vertically downward and the second dimension grows from left to
	  right.


       See also: ``export_matlab'', ``save''.

	  Error	codes:
	  1: First argument not	a string
	  2: Second argument not an integer matrix




  1.55.	 export_matlab



       [] = export_matlab(fn...)
	export_matlab("file") saves all	variables in Tela
	  workspace in "file". Any previous contents of	"file"
	  are overwritten. The data are	written	in MATLAB
	  binary format.

	  export_matlab("file","var1","var2"...) saves only the
	  specified variables. Notice that you have to give the
	  variable names as strings.

	  The resulting	MAT-file can be	read using the
	  MATLAB 'load'	command.

	  Limitations (bugs): It is not	possible to export
	  local	variables. If you try, the global ones will
	  be written, if they have numeric values. Use
	  export_matlab2 to achieve this, and to have explicit
	  control of variable naming.



       See also: ``export_matlab2'', ``save'', ``load'', ``import''.

	  Error	codes:
	  1: Too few arguments
	  2: Argument not a string
	  3: Write error on file






  1.56.	 export_matlab2



       [] = export_matlab2(fn...)
	export_matlab2("file", var1,"name1", var2,"name2"...)
	  saves	objects	var1,var2... in	MATLAB binary format in	"file".
	  The objects will be named "name1", "name2"...	.
	  Any previous contents	of "file" are overwritten.
	  workspace in "file". Any previous contents of	"file"
	  is overwritten.

	  The resulting	MAT-file can be	read using the
	  MATLAB 'load'	command.



       See also: ``export_matlab'', ``save'', ``load'',	``import''.

	  Error	codes:
	  1: First arg not a string
	  2: Even number of arguments
	  3: Write error on file
	  4: The 'name'	argument is not	a string





  1.57.	 eye



       [A] = eye(n)
	eye(n) returns the (integer) unit matrix of order n.
	  n must be a non-negative scalar integer.
	  eye(V) where V is a two-element integer vector with
	  both elements	equal and positive works also, thus
	  you can also use eye(size(A)).


       See also: ``ones'', ``inv''.

	  Error	codes:
	  -1: Argument not an integer or IntArray
	  -2: Negative dimension
	  -3: IntArray rank not	1
	  -4: IntArray length not 2
	  -5: Integer vector elements are unequal






  1.58.	 fclose



       [] = fclose(fnum)
	fclose(fnum) closes file with given identification number.
	  The fnum must	have been previously obtained from fopen.


       See also: ``fopen'', ``fformat''.

	  Error	codes:
	  -1: Bad argument: not	integer
	  -2: Bad argument: outside range
	  3: File was not open





  1.59.	 fformat



       [] = fformat(fnum,str...)
	fformat(fnum,"format-string",arg1,arg2,...) is similar to format,
	  except that it does not output to stdout but to opened file.


       See also: ``format'', ``sformat'', ``fopen''.

	  Error	codes:
	  -1: First argument not integer
	  -2: First argument not a valid file number
	  -3: Second argument not a string or char
	  4: File is not open




  1.60.	 find



       [y] = find(x)
	I=find(V) returns the index vector I=(i) for which
	  V[i] is nonzero. V must be an	integer	array. The length
	  of I is equal	to the number of nonzeros in V.
	  If V is multidimensional, it is used in flattened form.


       See also: ``any'', ``all'', ``flatten''.

	  Error	codes:
	  1: Argument not integer vector





  1.61.	 flatten



       [y] = flatten(;x)
	flatten(x) returns the array x flattened to a vector.
	  If x is not an array,	it is returned as is.
	  x = flatten()	flattens x "in place". This is much faster
	  (it works in constant	time) than to do x = flatten(x),
	  since	no data	movement is involved.





  1.62.	 floor



       [y] = floor(x)
	floor(x) returns the largest integer which is smaller than x.
	  x must be integer or real scalar or array. If	it is an array,
	  the operation	is applied componentwise.


       See also: ``ceil''.

	  Error	codes:
	  -1: Complex or nonnumeric input argument





  1.63.	 fopen



       [fnum] =	fopen(name,mode)
	fopen("filename",mode) opens a file and	returns
	  its identifier (integer). The	mode parameter can be
	  "r" or "w" for reading and writing, respectively.
	  If the open is not succesful,	-1 is returned.



  See also: ``fformat'', ``fclose''.

     Error codes:
     -1: First arg not a string
     -2: Second	arg not	a string
     -3: Too many open files
     -4: Bad string for	second arg





  1.64.	 format



       [] = format(str...)
	format("format-string",arg1,arg2,...) prints "format-string"
	  to standard output, replacing	occurrences of `format-spec`
	  with consecutive args. `Format-spec` is either empty,	i.e. ``,
	  or of	the form

	      `[-]w[.d]`.

	  Here w is the	field width (unsigned integer) and d is	the number
	  of significant digits, also unsigned integer.	By default the
	  argument is printed left-justified, but the optional minus sign
	  dictates right justification.	The backquote character	`  can be
	  produced by writing it three times: ```.

	  Hint:	You can	add any	number of spaces before	the closing backquote,
	  for example `20.7    `.
	  These	spaces do not affect the output. This feature can be used
	  to justify source code lines.


       See also: ``fformat'', ``sformat''.

	  Error	codes:
	  1: First argument not	a string or char





  1.65.	 fprintf



       [] = fprintf(fnum,formatstr...)
	fprintf(fnum,"format-string",arg1,arg2,...) is an interface to the C
	  fprintf function. The	format string should have a percent slot
	  for every arg. The args may be integer or real scalars or strings.
	  The file identifier fnum must	have been obtained from	fopen.

	  Notice: The stream is	not flushed after every	fprintf	operation,
	  but a	flush occurs whenever you switch from using fprintf to
	  fformat on the same file. Therefore avoid mixing fprintf and fformat
	  on the same file if performance is an	issue for you!



       See also: ``fopen'', ``printf'',	``sprintf'', ``format''.



     Error codes:
     1:	Bad argument type
     2:	Second arg not a string
     3:	First argument not an integer
     4:	Bad file identifier: out of range
     5:	File is	not open
     6:	Internal error:	fdopen failed






  1.66.	 geotoecc



       [latmag,longmag]	= geotoecc(lat,longit)
	[latmag,longmag] = geotoecc(lat,long) transforms geographic
	  latitude and longitude to eccentric geomagnetic latitude and longitude.
	  All angles in	degrees.


       See also: ``ecctogeo'', ``geotoeccXYZ'',	``geotomag'', ``magtogeo''.

	  Error	codes:
	  -1: Bad first	arg
	  -2: Bad second arg






  1.67.	 geotoeccXYZ



       [x1,y1,z1] = geotoeccXYZ(x,y,z)
	[x1,y1,z1] = geotoeccXYZ(x,y,z)	transforms geographic
	  point	(x,y,z)	to eccentric dipole coordinates	(x1,y1,z1).


       See also: ``geotomagXYZ'', ``ecctogeoXYZ'', ``geotoecc''.

	  Error	codes:
	  -1: Bad first	arg
	  -2: Bad second arg
	  -3: Bad third	arg






  1.68.	 geotomag



       [latmag,longmag]	= geotomag(lat,longit)
	[latmag,longmag] = geotomag(lat,long) transforms geographic
	  latitude and longitude to geomagnetic	dipole latitude	and longitude.
	  All angles in	degrees.



  See also: ``geotomagXYZ'', ``magtogeo'', ``ecctogeo'', ``geotoecc''.

     Error codes:
     -1: Bad first arg
     -2: Bad second arg






  1.69.	 geotomagXYZ



       [x1,y1,z1] = geotomagXYZ(x,y,z)
	[x1,y1,z1] = geotomagXYZ(x,y,z)	transforms geographic
	  point	(x,y,z)	to geomagnetic dipole coordinates (x1,y1,z1).


       See also: ``geotomag'', ``magtogeoXYZ''.

	  Error	codes:
	  -1: Bad first	arg
	  -2: Bad second arg
	  -3: Bad third	arg






  1.70.	 getenv



       [y] = getenv(varname)
	getenv("envvar") returns the value of environment variable
	  "envvar", or VOID if such variable is	not defined in
	  the UNIX environment.
	  Error	codes:
	  -1: Argument not a string or char






  1.71.	 gnuplot



       [] = gnuplot(x)
	gnuplot(x) calls GNUPLOT on vector x.
	  Error	codes:
	  -1: Cannot open command pipe to gnuplot
	  -2: Cannot open data pipe





  1.72.	 grid



  [X,Y]	= grid(x,y)
   [X,Y] = grid(x,y) produces matrices X,Y that	are formed from	vectors	x,y
     such that X[i,j] =	x[i] for all j,	and Y[i,j] = y[j] for all i.


  See also: ``grid3''.

     Error codes:
     -1: Input argument	is array but not a vector
     -2: Input argument	is not real array





  1.73.	 grid3



       [X,Y,Z] = grid3(x,y,z)
	[X,Y,Z]	= grid3(x,y,z) produces	3D arrays X,Y,Z	that ar
	  formed from vectors x,y,z such that
	  X[i,j,k] = x[i] for all j,k,
	  Y[i,j,k] = y[j] for all i,k, and
	  Z[i,j,k] = z[k] for all i,j.


       See also: ``grid''.

	  Error	codes:
	  -1: Input arg	is array but not a vector
	  -2: Input arg	not a real array





  1.74.	 help



       [] = help(;fn)
	help(function-name) or help("help-item") displays the help information
	  associated with a given function or a	given help item. On command line
	  you may use the abbreviation

	     ?help-item
	  or
	     help help-item

	  These	forms are translated to	help("help-item") before parsing.

	  First	tries:
	  help operators
	  help special
	  help if
	  help for
	  help function
	  ...

	  Error	codes:
	  1: Item not found
	  2: Cannot open help file



  1.75.	 herm



       [B] = herm(A; P)
	herm(A)	is the same as conj(transpose(A)).
	  herm(A,P) is the same	as conj(transpose(A,P)).
	  You can abbreviate "herm(A)" as "A'".


       See also: ``transpose''.

	  Error	codes:
	  -1: Permutation argument not integer array
	  -2: Permutation argument of bad rank or size
	  -3: Permutation argument contains invalid integers





  1.76.	 hide



       [] = hide(...)
	hide("sym-name",...) sets the 'hidden' attribute to
	  specified symbols.


       See also: ``whos'', ``unhide'', ``autoglobal''.

	  Error	codes:
	  1: Argument not a string
	  2: Argument does not name a symbol






  1.77.	 hist



       [;ndata,xdata] =	hist(x...)
	hist(x)	produces a histogram of	vector x.
	  The range min(x)..max(x) is divided in bins, and the
	  number of x values in	each bin is counted. The count determines
	  the height of	each bin.

	  hist(x) uses 10 bins,	hist(x,n) uses n bins.
	  hist(x,n,a) starts from x=a.
	  hist(x,n,a,b)	ignores	x values outside interval a..b.
	  Rest of the args may contain other MTV options.
	  [ndata,xdata]	= hist(args) returns the count and abscissa vectors
	  but does not draw anything. bar(xdata,ndata,"lab") can be used to draw
	  the histogram	later. Graphics	options	are ignored in this case.


       See also: ``plot'', ``bar''.





     Error codes:
     1:	First argument not a (real) vector
     2:	Second arg not a positive integer
     3:	Third arg not a	(real) scalar
     4:	Fourth arg not a (real)	scalar
     5:	Third arg greater of equal than	fourth arg
     6:	Could not open temporary MTV file
     7:	Syntax error in	graph options






  1.78.	 hold



       [] = hold(flag)
	hold(on) and hold(off) set the graphics	hold mode on and off.
	  When hold is on, all graphics	commands will be accumulated and
	  performed only until hold(off).
	  If hold(on) is called	many times in succession, also hold(off)
	  must be called as many times until the plots are produced.
	  For example, if

	  function f() {hold(on); plot1(); plot2(); hold(off)};

	  and it is called as

	  hold(on); f(); plot3(); hold(off);

	  then all three plots are actually combined in	one plot.


       See also: ``plot'', ``holdmode''.

	  Error	codes:
	  1: Argument not an integer





  1.79.	 holdmode



       [result]	= holdmode(;flag)
	holdmode(overlay) causes held plots to be combined in same figure.
	  holdmode(paging) shows them as sequential pages in one window.
	  holdmode(stacking) draws them	as subplots in one window.
	  holdmode() returns the current setting.


       See also: ``hold''.

	  Error	codes:
	  1: Argument not an integer
	  2: Bad value for argument






  1.80.	 import



       [] = import(filename)
	import("file") tries to	load the contents of "file" in Tela workspace.
	  All files accepted by	load are also accepted by import. In addition,
	  import accepts more general HDF files	and MATLAB binary files.
	  Create these files using the MATLAB 'save' command.

	  Restrictions:
	  1) Only MATLAB files created on a similar architecture can be
	  correctly imported. If this rule is not followed, the	imported
	  data will be garbage!
	  2) MATLAB4.0 and higher saves	arrays with more than 10000 elements
	  as various integer formats, if all elements are whole	numbers.
	  Tela cannot read these files.	A workaround is	to perturb one element
	  in MATLAB before saving so that it is	not exactly integer.

	  For filename conventions, see	load.


       See also: ``load'', ``save'', ``import1'', ``export_matlab''.


	  (The difference between import and import1 is	that import1 reads
	   only	one object and returns it, whereas import reads	several
	       objects and assigns them	directly to workspace variables.)
	  Error	codes:
	  1: Argument not string or char
	  2: Argument is not an	HDF file
	  3: File not found
	  4: Cannot import file
	  5: Unused error message
	  6: Cannot import this	Matlab file (O(letter'Oh) != 0,	(can even Matlab?))
	  7: Cannot import this	Matlab file (P != 0). Is your array size >10000	and all	integer? Try perturbing	it
	  8: Cannot import this	Matlab file (T != 0, 1). Is it a sparse	matrix?	Make it	full
	  10: Bad Matlab binary	file, premature	end of file






  1.81.	 import1





















  [x] =	import1(filename; label)
   import1("file") reads one object from "file". The imported
     object is returned. "File"	can be one of the following:

     1)	HDF file, in which case	the first Scientific Data Set (SDS)
	is imported. The form import1("file.hdf","label") reads	SDS
	with label "label", which is not necessarily the first one.

     2)	D-style	ASCII file of the following format:

	  (line	1)   D=Nt dim1 dim2 ...	dimN
	  (any number M	of blank lines or lines	starting with '#')
	  (line	M+2) data1 data2 ....

	 where N is the	rank of	the dataset and	t is an	optionial
	 type specification letter: t may be either 'r', 'i', or 'c'
	 for real, integer and complex data, respectively. If t	is
	 missing, real data are	asssumed.

     3)	Plain ASCII file of nrows x ncols real numbers.	If nrows or
	ncols is 1, it will be returned	as a vector, otherwise as a
	matrix.	Missing	entries	are treated as zeros. This format
	is similar to Matlab's load for	ASCII, except that '#'
	comments are accepted in the beginning.



  See also: ``import'',	``load'', ``save''.

     See import	for a difference between import	and import1.
     For filename conventions, see load.
     Error codes:
     -1: Input arg not a char or string
     -2: File not found
     -3: Unknown format	in ASCII file
     -4: Unknown format	in ASCII file
     -5: Too high rank ASCII data
     -6: Syntax	error in ASCII file dimension specification
     -7: Syntax	error when reading D-style ASCII data
     -8: Internal error
     -9: Cannot	import file
     -10: Second arg not a string
     -11: Specified label not found
     -12: Premature end	of file	in D-style ASCII
     -13: Syntax error when reading plain ASCII	data






  1.82.	 info



       [] = info()
	info() shows information about various class sizes for this Tela implementation.
	  It also prints the total counts of Tnode, Tprg and Tobject objects at	the moment.








  1.83.	 input_string



       [s] = input_string()
	input_string() waits for an input line from the	keyboard
	  and returns it as a string. The newline is not included
	  in the result.
	  If the string	is enclosed in double quotes, they are removed.
	  Error	codes:
	  -1: EOF encountered.





  1.84.	 intpol



       [y] = intpol(A...)
	intpol(A,index1,index2...) is a	general	interpolation
	  function. A must be an array from which values are interpolated.
	  The rank of A	must equal the number of index arguments.
	  Each index argument may be a real scalar or real array.
	  All index arguments must mutually agree in type and rank.
	  The array A may also be complex. The result y	is of same
	  rank and size	as each	of the index arguments.

	  intpol(A,i,j,...) is a generalization	of mapped indexing
	  A<[i,j,...]> for non-integral	indices. The function benefits
	  from vectorization even more than most other Tela functions.

	  Currently intpol uses	linear interpolation.
	  Error	codes:
	  -1: First arg	not a numerical	array
	  -2: Rank of first arg	does not match number of index args
	  -3: Non-real index arg
	  -4: Dissimilar index args
	  -6: Range overflow





  1.85.	 inv



       [B] = inv(A)
	inv(A) returns the inverse of a	square matrix A.
	  A may	be integer, real or complex valued.
	  A may	also be	a scalar, in which case	its reciprocal
	  is returned.


       See also: ``linsolve'', ``LU'', ``chol'', ``matprod'', ``det'',
       ``eig''.

	  Error	codes:
	  -1: Nonnumeric input arg
	  -2: Input array is not a matrix
	  -3: Input matrix is not square
	  -4: Singular matrix
	  -5: Singular matrix

  1.86.	 invFFT



       [f] = invFFT(u; dim)
	invFFT() is the	inverse	of FFT().
	  For vector f,	u=invFFT(f) is equivalent with

	  n = length(f); u = czeros(n);
	  for (j=1; j<=n; j++)
	      u[j] = (1/n)*sum(f*exp((j-1)*(0:n-1)*2i*pi/n));

	  Differences with FFT:	sign of	i is plus, scale factor	1/n.



       See also: ``FFT''.

	  Error	codes:
	  -1: First argument not a numeric array
	  -2: Second argument not integer
	  -3: Second argument out of range






  1.87.	 invcosFFT



       [f] = invcosFFT(u; dim)
	invcosFFT() is the inverse of cosFFT().
	  Actually invcosFFT differs from cosFFT only by normalization,
	  but it is provided as	a separate function for	convenience.

	  For vector f,	u=invcosFFT(f) is equivalent with

	  n = length(f); u = zeros(n);
	  for (j=1; j<=n; j++)
	      u[j] = (f[1] - (-1)^j*f[n] + 2*sum(f[2:n-1]*cos((1:n-2)*(j-1)*pi/(n-1))))/(2*n-2)



       See also: ``cosFFT''.

	  Error	codes:
	  -1: First argument not a real	array
	  -2: Second argument not integer
	  -3: Second argument out of range






  1.88.	 invcosqFFT








  [f] =	invcosqFFT(u; dim)
   invcosqFFT()	is the inverse of cosqFFT()
     (inverse quarter-wave cosine Fourier transform).

     For vector	f, u=invcosqFFT(f) is equivalent with

     n = length(f); u =	zeros(n);
     for (j=1; j<=n; j++)
	 u[j] =	(1/n)*sum(f*cos((2*(1:n)-1)*(j-1)*pi/(2*n)));



  See also: ``cosqFFT''.

     Error codes:
     -1: First argument	not a real array
     -2: Second	argument not integer
     -3: Second	argument out of	range






  1.89.	 invrealFFT



       [f] = invrealFFT(u; dim,oddevenspec)
	invrealFFT() is	the inverse of realFFT().
	  invrealFFT(u,dim,"even") and invrealFFT(u,dim,"odd") specifies
	  even or odd transform	length,	respectively.
	  invrealFFT(u,dim,N) uses the same evenness as	the integer N has.

	  If the evenness is not specified explicitly, the imaginary parts
	  of the highest frequency components are tested. If they are all zero
	  the transform	length is even,	otherwise odd. However,	this automatic
	  method will fail if the imaginary parts are not EXACTLY zero.	If you
	  use multiple FFTs to solve a PDE, for	example, you should probably
	  specify the evenness explicitly.


       See also: ``realFFT''.

	  Error	codes:
	  -1: First argument not a complex array
	  -2: Second argument not integer
	  -3: Second argument out of range
	  -4: Third argument not "even", "odd" or an integer






  1.90.	 invsinFFT










  [f] =	invsinFFT(u; dim)
   invsinFFT() is the inverse of sinFFT().
     Actually invsinFFT	differs	from sinFFT only by normalization,
     but it is provided	as a separate function for convenience.

     For vector	f, u=invsinFFT(f) is equivalent	with

     n = length(f); u =	zeros(n);
     for (j=1; j<=n; j++)
	 u[j] =	(1/(n+1))*sum(f*sin((1:n)*j*pi/(n+1)));



  See also: ``sinFFT''.

     Error codes:
     -1: First argument	not a real array
     -2: Second	argument not integer
     -3: Second	argument out of	range






  1.91.	 invsinqFFT



       [f] = invsinqFFT(u; dim)
	invsinqFFT() is	the inverse of sinqFFT()
	  (inverse quarter-wave	sine Fourier transform).

	  For vector f,	u=invsinqFFT(f)	is equivalent with

	  n = length(f); u = zeros(n);
	  for (j=1; j<=n; j++)
	      u[j] = (1/n)*sum(f*sin((2*(1:n)-1)*j*pi/(2*n)));



       See also: ``sinqFFT''.

	  Error	codes:
	  -1: First argument not a real	array
	  -2: Second argument not integer
	  -3: Second argument out of range






  1.92.	 isCfunction



       [y] = isCfunction(x)
	isCfunction(x) returns 1 if x is a C-tela function.
	  and 0	otherwise.


       See also: ``isfunction'', ``isTfunction''.



  1.93.	 isTfunction



       [y] = isTfunction(x)
	isTfunction(x) returns 1 if x is a function written in Tela
	  and 0	otherwise.


       See also: ``isfunction'', ``isCfunction''.



  1.94.	 isarray



       [y] = isarray(x)
	isarray(x) returns 1 if	x is an	array and 0 if it is not.


       See also: ``isscalar'', ``isvector'', ``ismatrix''.



  1.95.	 ischar



       [y] = ischar(x)
	ischar(x) returns 1 if x is a character	and 0 otherwise.


       See also: ``isstring'', ``isstr''.



  1.96.	 iscomplex



       [y] = iscomplex(x)
	iscomplex(x) returns 1 if x is a complex array or scalar,
	  and 0	if it is real or integer or a nonnumeric object.


       See also: ``isreal'', ``isfloat'', ``isint''.



  1.97.	 isdefined



       [y] = isdefined(x)
	isdefined(x) returns 1 if x is not undefined and 0 if
	  it is	undefined. Optional function arguments are undefined
	  if not assigned by the caller; isdefined can be used
	  inside the function to test whether this is the case.


       See also: ``isundefined''.




  1.98.	 isfinite



       [y] = isfinite(x)
	isfinite(x) returns 1 if x is a	finite number and 0 otherwise.
	  If x is array, the operation is applied componentwise.
	  If x is non-numeric it is considered not finite.
	  Integer and consequently strings and chars are always	finite.





  1.99.	 isfloat



       [y] = isfloat(x)
	isfloat(x) returns 1 if	x is a floating	point array
	  or scalar, and 0 otherwise. Notice the difference between
	  isfloat and isreal. isreal(x)	is 1 for integer objects,
	  while	isfloat(x) is 0.


       See also: ``isreal'', ``isint'',	``iscomplex''.



  1.100.  isfunction



       [y] = isfunction(x)
	isfunction(x) returns 1	if x is	a function
	  (Tela-function, C-tela function or intrinsic function)
	  and 0	otherwise.


       See also: ``isCfunction'', ``isTfunction''.



  1.101.  isint



       [y] = isint(x)
	isint(x) returns 1 if x	is integer scalar or array
	  and 0	if it is not.


       See also: ``isreal'', ``isfloat'', ``iscomplex''.



  1.102.  ismatrix



       [y] = ismatrix(x)
	ismatrix(x) returns 1 if x is a	matrix (2D array)
	  and 0	if it is not.



  See also: ``isscalar'', ``isvector'',	``isarray''.



  1.103.  isreal



       [y] = isreal(x)
	isreal(x) returns 1 if x is numerical non-complex
	  array	or scalar, and 0 otherwise.


       See also: ``isfloat'', ``isint'', ``iscomplex''.



  1.104.  isscalar



       [y] = isscalar(x)
	isscalar(x) returns 1 if x is scalar and 0 if it is not.


       See also: ``isvector'', ``ismatrix'', ``isarray''.



  1.105.  isstr



       [y] = isstr(x)
	isstr(x) returns 1 if x	is a character or string
	  and 0	otherwise.


       See also: ``isstring'', ``ischar''.

	  NOTICE: Usually you want to use isstr, not isstring.





  1.106.  isstring



       [y] = isstring(x)
	isstring(x) returns 1 if x is a	string and 0 otherwise.


       See also: ``ischar'', ``isstr''.

	  NOTICE: Usually you want to use isstr, not isstring.





  1.107.  isundefined



  [y] =	isundefined(x)
   isundefined(x) returns 1 if x is not	undefined and 0	if
     it	is undefined. Optional function	arguments are undefined
     if	not assigned by	the caller; isdefined can be used
     inside the	function to test whether this is the case.


  See also: ``isdefined''.



  1.108.  isvector



       [y] = isvector(x)
	isvector(x) returns 1 if x is a	vector and 0 if	it is not.


       See also: ``isscalar'', ``ismatrix'', ``isarray''.



  1.109.  isvoid



       [y] = isvoid(x)
	isvoid(x) returns 1 if x is a void value and 0 otherwise.





  1.110.  length



       [L] = length(x)
	length(x) returns the total number of elements in array	x.
	  If x is scalar, length(x) is 1. If x is undefined, an	error
	  results.


       See also: ``size'', ``rank''.

	  Error	codes:
	  -1: Argument has undefined value





  1.111.  link












  [] = link(filename)
   link("file.o") makes	C-tela functions in "file.o" available
     to	Tela. "file.o" must be compiled	from a C-tela file
     (usually "file.ct").
     Error codes:
     1:	Cannot initialize DLD
     2:	Cannot link-load file
     3:	Argument not string or char
     4:	Cannot find fninfo pointer
     5:	Internal inconsistency
     6:	Undefined symbols remain
     7:	main function returned error code
     8:	Could not dlclose the previous linkage
     9:	Too many dynamically linked modules
     10: File not found






  1.112.  linsolve



       [x] = linsolve(A,b)
	linsolve(A,b) solves the linear	system A**x == b.
	  If A is square, the result x is roughly the same as
	  computing inv(A)**b (however,	using linsolve is
	  faster and numerically more accurate). If A is not
	  square, a least-square problem is solved. If the system
	  is overdetermined, the solution x minimizes the quantity
	  |A**x	- b|. If the system is underdetermined,	the
	  solution x minimizes |x| among all x that satisfy
	  A**x==b.
	  The second argument may be a vector or a matrix.
	  If it	is a matrix, several linear systems are	effectively
	  solved simultaneously.


       See also: ``inv'', ``LU'', ``eig'', ``SVD''.

	  Error	codes:
	  -1: First input arg is not an	array
	  -2: First input arg is not a matrix
	  -3: Second input arg is not an array
	  -4: Second input arg is not a	vector or matrix
	  -5: Incompatible dimensions in first/second args
	  -6: Matrix must be square
	  -7: Singular matrix
	  -8: Internal error






  1.113.  load








  [] = load(filename)
   load("file")	loads the contents of "file"
     in	Tela workspace.
     "file" must have been previously created using
     the 'save'	command; it must be in a certain
     HDF format.

     Filename conventions:
     If	the filename starts with "/", "./" or "..",
     it	is considered absolute.	Otherwise it is	searched
     along TELAPATH. This applies to other file
     operations	as well.

     The counterpart of	load is	save.
     To	read more general HDF files and	ASCII files,
     see import1.
     To	load more general HDF files and	MATLAB binary
     files, see	import.


  See also: ``save'', ``import'', ``import1'', ``export_matlab''.

     Error codes:
     1:	Argument not string or char
     2:	Argument is not	an HDF file
     3:	File not found






  1.114.  log



       [y] = log(x)
	y = log(x) computes the	natural	logarithm of x.
	  If x is complex, the result is complex. If x is real or
	  integer, but negative, the result is complex (purely
	  imaginary). If x is real or integer and non-negative,
	  the result is	real.
	  If x is an array, the	operation is applied componentwise.
	  If some of the components are	negative, all components
	  of the result	are complex.





  1.115.  m2i



       [theta,phi] = m2i(Kp,x,y)
	[theta,phi] = m2i(Kp,x,y) maps the equatorial plane point (x,y,z=0)
	  to the northern ionosphere. Inputs: Kp, the Kp index;	x,y,z, GSM
	  coordinates in Earth radii. Outputs: colatitude and longitude	in
	  magnetic coordinates in degrees.


       See also: ``T89'', ``geotomag''.

	  Error	codes:
	  -1: Bad type of input	arg

  1.116.  magtogeo



       [lat,longit] = magtogeo(latmag,longmag)
	[lat,long] = magtogeo(latmag,longmag) transforms geomagnetic
	  latitude and longitude to geographic latitude	and longitude.
	  All angles in	degrees.


       See also: ``geotomag'', ``magtogeoXYZ'',	``geotoecc'', ``ecctogeo''.

	  Error	codes:
	  -1: Bad first	arg
	  -2: Bad second arg






  1.117.  magtogeoXYZ



       [x1,y1,z1] = magtogeoXYZ(x,y,z)
	[x1,y1,z1] = magtogeoXYZ(x,y,z)	transforms geomagnetic dipole
	  point	(x,y,z)	to geographic coordinates (x1,y1,z1).


       See also: ``magtogeo'', ``geotomagXYZ''.

	  Error	codes:
	  -1: Bad first	arg
	  -2: Bad second arg
	  -3: Bad third	arg






  1.118.  map



       [B] = map(fn,A,darg)
	[B] = map(fn,A,d) maps function	fn along d'th dimension
	  in array A. Fn is a functional argument. It must return a scalar
	  when called with one vector argument.	The type of the	scalar
	  returned (integer, real or complex) must not change between
	  calls	on similar type	vectors.

	  For example, map(sum,A,1) sums elements of matrix A along
	  columns, returning a vector.


       See also: ``mapmin'', ``mapmax''.








     Error codes:
     -1: First arg not a function
     -2: Second	arg not	a numerical array
     -3: Third arg not an integer scalar
     -4: Third arg (the	dimension) out of range
     -5: First arg (function) did not return a scalar when first called
     -6: First arg (function) unexpectedly changed its return type
     -7: First arg is an intrinsic function; it	is no good





  1.119.  mapmax



       [y;P] = mapmax(x;d)
	mapmax(x,d) finds maximum along	d'th dimension in array	x.
	  The result is	an array with rank one less than rank(x).
	  The array may	not be complex.
	  [M,p]	= mapmax(x,d) returns the maximum positions p along with
	  the maximums m. The array p is of the	same shape as M, but is
	  integer-valued.

	  mapmax(x) is a flattened form	which returns a	scalar result.
	  It is	equivalent to max(x). [M,p] = mapmax(x)	also works.


       See also: ``mapmin'', ``map''.

	  Error	codes:
	  -1: First arg	not a numerical	array
	  -2: Second arg not an	integer	scalar
	  -3: Second arg (the dimension) out of	range
	  -4: First arg	is complex





  1.120.  mapmin



       [y;P] = mapmin(x;d)
	mapmin(x,d) finds minimum along	d'th dimension in array	x.
	  The result is	an array with rank one less than rank(x).
	  The array x may not be complex.
	  [m,p]	= mapmin(x,d) returns the minimum positions p along with
	  the minimums m. The array p is of the	same shape as m, but is
	  integer-valued.

	  mapmin(x) is a flattened form	which returns a	scalar result.
	  It is	equivalent to min(x). [m,p] = mapmin(x)	also works.


       See also: ``mapmax'', ``map''.

	  Error	codes:
	  -1: First arg	not a numerical	array
	  -2: Second arg not an	integer	scalar
	  -3: Second arg (the dimension) out of	range
	  -4: First arg	is complex


  1.121.  matlab_call



       [...] = matlab_call(fname...)
	[a,b,c,...] = matlab_call("fname",d,e,f,...)
	  calls	a Matlab function in a currently running background
	  Matlab process. Input	arguments (any number) d,e,f,...
	  are sent to Matlab prior to call, and	output arguments
	  (any number) a,b,c,... are collected and returned to Tela
	  after	the function has completed.


       See also: ``matlab_start'', ``matlab_eval'', ``matlab_put'', ``mat-
       lab_get''.

	  Error	codes:
	  1: Unknown error when	sending	input argument
	  2: Function call unsuccessful
	  3: Internal error: No	such output argument in	Matlab workspace
	  4: Output argument is	of unsupported type (not double)
	  5: Output argument is	of unsupported type (not full matrix)
	  -1: Internal error: matlab_put or matlab_get first argument not a string
	  -2: No Matlab	process	running, use matlab_start first
	  -3: Input argument not interpretable as a matrix
	  -4: Input argument has too high (> 2)	rank
	  -5: First argument not a string






  1.122.  matlab_eval



       [retval]	= matlab_eval(str)
	matlab_eval("command") sends "command" to currently
	  running Matlab background process. It	returns	1
	  if succesful 0 if an error occurred.


       See also: ``matlab_start'', ``matlab_put'', ``matlab_call''.

	  Error	codes:
	  -1: Argument not a string
	  -2: No Matlab	process	running, use matlab_start first






  1.123.  matlab_get



       [y] = matlab_get(name)
	matlab_get("MatrixName") asks a	currently running background
	  Matlab process for a variable	named "MatrixName", and	returns
	  its value.


       See also: ``matlab_start'', ``matlab_put'', ``matlab_eval''.

     Error codes:
     -1: Argument not a	string
     -2: No Matlab process running, use	matlab_start first
     3:	No such	variable in Matlab workspace
     4:	The variable is	of unsupported type (not double)
     5:	The variable is	of unsupported type (not full matrix)






  1.124.  matlab_put



       [] = matlab_put(name,value)
	matlab_put("MatrixName",x) tries to interpret x	as
	  a Matlab matrix and sends it to currently running
	  background Matlab process. The matrix	is assigned to
	  variable "MatrixName"	in Matlab side.
	  matlab_put returns 1 if successful and 0 if not.


       See also: ``matlab_start'', ``matlab_get'', ``matlab_eval''.

	  Error	codes:
	  1: Unknown error
	  -1: First argument not a string
	  -2: No Matlab	process	running, use matlab_start first
	  -3: Second argument not interpretable	as a matrix
	  -4: Second argument has too high (> 2) rank






  1.125.  matlab_start



       [] = matlab_start(;startcmd)
	matlab_start() starts a	new Matlab process on background.
	  You can send to it commands with matlab_eval.
	  matlab_start("startcmd") uses	"startcmd" to start up
	  Matlab. The default "startcmd" is "matlab".
	  If matlab_start() has	already	been called, a new call
	  is harmless and does nothing.


       See also: ``matlab_eval'', ``matlab_call'', ``matlab_stop''.

	  Error	codes:
	  1: Could not start Matlab
	  -1: Argument not a string






  1.126.  matlab_stop



  [] = matlab_stop()
   matlab_stop() stops a currently running Matlab process.


  See also: ``matlab_start'', ``matlab_eval''.

     Error codes:
     1:	No Matlab process running; none	to be stopped
     2:	Unknown	error occurred when trying to stop Matlab process






  1.127.  matprod



       [C] = matprod(A,B; Aflag,Bflag)
	matprod(A,B) returns the matrix	product	of A and B.
	  If at	least one of A and B is	scalar,	matprod(A,B) is	the
	  same as their	ordinary product A*B. If both A	and B
	  are arrays, their "inner" dimensions must agree.
	  That is, the last dimension of A must	equal the first
	  dimension of B.
	  You can abbreviate matprod(A,B) as A**B.

	  Optional args: matprod(A,B,aflag,bflag) can be used to
	  transpose or Hermitian-conjugate the factors before the
	  product. 'n' means no	operation, 't' means transpose and
	  'h' means Hermitian conjugate. For example,

	  matprod(A,B,'h') = A'**B = herm(A)**B
	  matprod(A,B,'n','t') = A**B.'	= A**transpose(B)

	  Normally you need not	use matprod explicitly,	but you
	  can use the operator **, which is internally translated
	  to matprod. Hermitian	conjugates and transposes in
	  connection with ** produce the corresponding 'h' and
	  't' options in matprod. For example,

	  A'**B	       generates       matprod(A,B,'h')
	  A.'**B'      generates       matprod(A,B,'t','h')
	  A**B.'       generates       matprod(A,B,'n','t')

	  and so on. The runtime is optimal for	all these operations.


       See also: ``inv''.


	  Error	codes:
	  -1: Inner dimensions do not agree
	  -2: Resulting	array would have too high rank
	  -3: Third arg	not one	of 'n',	't', 'h'
	  -4: Fourth arg not one of 'n', 't', 'h'









  1.128.  menu



       [result]	= menu(title...)
	choice = menu("title","choice1","choice2",...) displays
	  a menu of choices and	returns	the number entered by
	  the user.


       See also: ``smenu''.

	  Error	codes:
	  -1: Less than	two input args





  1.129.  mesh



       [] = mesh(z...)
	mesh(z[,options]) plots	the matrix z as	a 3D mesh.


       See also: ``annotate'', ``plot'', ``contour'', ``pcolor'', ``vplot''.

	  Error	codes:
	  1: Could not open temporary MTV file
	  2: First argument is not a numeric 2D	array
	  3: Syntax error in graph options
	  4: Write error in MTV	file - file system full?





  1.130.  ones



       [y] = ones(...)
	ones(n,m...) returns an	integer	array with all elements
	  equal	to 1 of	size n x m x ... .

	  ones(V) where	V is an	integer	vector,	and thus
	  ones(size(A))	work also.


       See also: ``rand'', ``eye''.


	  Error	codes:
	  -1: Input argument not an integer or IntVector
	  -2: Rank of requested	tensor array exceeds MAXRANK
	  -3: Non-positive input argument
	  -4: Negative input argument
	  -5: Integer array rank not 1






  1.131.  pause



       [] = pause()
	pause()	will wait for a	keypress on keyboard.





  1.132.  pcolor



       [] = pcolor(z...)
	pcolor(z[,options]) plots the matrix z as a pseudocolor	density	plot.


       See also: ``annotate'', ``plot'', ``contour'', ``mesh'',	``vplot''.

	  Error	codes:
	  1: Could not open temporary MTV file
	  2: First argument is not a numeric 2D	array
	  3: Syntax error in graph options
	  4: Write error in MTV	file - file system full?





  1.133.  perf



       [v] = perf()
	perf() returns an array	containing all maintained operation
	  counters. To measure performance of a	code segment, do

	  p0=perf(); mycode(); p=perf()-p0;

	  Now you can apply various performance-related	functions to p:
	  for example cputime(p), Mflops(p).





  1.134.  plot



       [] = plot(...)
	plot(x1,y1,[options1], x2,y2,[options2],...) is	the basic 2D plot function.
	  Each vector yi is plotted versus the corresponding xi. All curves yi are
	  displayed in the same	figure.	The option sequences must consist of keyword-
	  value	pairs. Example:

	      x	= 0:0.1:4*pi;
	      plot(x,sin(x), "linewidth",3,"linecolor",2);

	  The abscissa x may be	missing, in which case the default of 1:length(y)
	  is used. The ordinates y may be matrices; then each row produces one
	  curve. If also abscissa x is matrix, the x-value may be different for	each
	  curve.

  See also: ``plot3'', ``annotate'', ``plotopt'', ``mesh'', ``contour'',
  ``pcolor'', ``vplot''.

     Error codes:
     1:	Could not open temporary MTV file
     2:	Nonnumeric or complex data argument
     3:	Syntax error in	graph options
     4:	The abscissa ("x") must	be a vector or a matrix
     5:	The ordinate ("y") must	be a vector or a matrix
     6:	x and y	dimensions disagree






  1.135.  plot3



       [] = plot3(x,y,z...)
	plot3(x,y,z[,options]) produces	parametric space curves.
	  The quantities x,y,z must have equal ranks, and they can
	  be either vectors or matrices. If they are vectors, only
	  one space curve is drawn. If they are	matrices, the number
	  of curves produces equals the	number of rows.


       See also: ``plot'', ``annotate''.

	  Error	codes:
	  1: Could not open temporary MTV file
	  2: y dimensionality disagrees	with x dimensionality
	  3: z dimensionality disagrees	with x dimensionality
	  4: Input arrays must be integer or real arrays
	  5: Input arrays must have rank equal to 1 or 2
	  6: Syntax error in graph options






  1.136.  plotopt



       [] = plotopt(s)
	plotopt("-3d -colorps -landscape...") sets a set of PlotMTV command
	  line options for subsequent graphics commands	(global	setting).


       See also: ``plot'', ``annotate''.


	  NOTICE: plotopt is usually not required. You can pass	the option string
	  to all plot commands directly, for example:

	  plot(x,sin(x),"-3d -landscape");

	  These	options	affect only the	current	(or next outputted, if hold is used)
	  plot.	Include	only

	  Error	codes:
	  1: Argument not a string

  1.137.  printf



       [] = printf(formatstr...)
	printf("format-string",arg1,arg2,...) is an interface to the C
	  printf function. The format string should have a percent slot
	  for every arg. The args may be integer or real scalars or strings.


       See also: ``fprintf'', ``sprintf'', ``format''.

	  Error	codes:
	  1: Bad argument type
	  2: First arg not a string






  1.138.  prod



       [y] = prod(x;d)
	prod(x)	multiplies all the elements of x, if x is an array.
	  prod(x,d) takes the product along d'th dimension only, returning
	  an array of rank one less than rank(x).
	  If x is scalar, it is	returned as such.
	  If I is integer array, prod(I) will be of type real if the product
	  would	cause integer overflow.	In all other cases, including prod(I,d),
	  the type of y	equals the component type of x.


       See also: ``sum'', ``cumprod''.

	  Error	codes:
	  -1: Nonnumeric input arg
	  -2: Second argument not an integer
	  -3: Second argument (dimension spec) out of range





  1.139.  quit



       [] = quit()
	quit() stops Tela. quit() is synonym for exit().





  1.140.  rand








  [x] =	rand(...)
   rand() returns a random real	x, 0<=x<1.
     rand(N) (N	positive integer) returns a real random	vector of length N.
     rand(N,M) returns a random	matrix,	and so on.
     Error codes:
     -1: Tried to create too high rank array
     -2: Argument not an integer
     -3: Non-positive integer argument





  1.141.  rank



       [y] = rank(x)
	rank(A)	returns	the number of dimensions of array A.
	  The rank of a	scalar is 0. The rank of a nonnumeric
	  object, including undefined value, is	-1. The	rank function
	  never	generates an error.


       See also: ``length'', ``size''.



  1.142.  realFFT



       [f] = realFFT(u;	dim)
	realFFT(u) gives the Fast Fourier Transform of real array u.
	  If u's rank is more than one,	the transform is computed
	  only along the first dimension (many independent 1D
	  transforms).

	  realFFT(u,dim) computes the FFT along	the specified dimension.
	  The first dimension is labeled 1 and so on.

	  The result of	realFFT() is the same as FFT() except that only
	  nonnegative frequency	components are returned. The result is
	  always complex array.	The first component (0 frequency) has always
	  zero imaginary part. If the transform	length is even,	the last
	  component has	zero imaginary part as well. Notice that these
	  conventions are different from some generally	used C and Fortran
	  library routines, which return a real	array force-fitted
	  in the same space as the input array by not storing the zero
	  imaginary parts. The Tela convention allows you to manipulate	the
	  result in k-space more easily	because	it is already complex.

	  realFFT is the most efficient	when the transform length is
	  a product of small primes.



       See also: ``invrealFFT'', ``FFT'', ``sinFFT'', ``cosFFT'', ``sin-
       qFFT'', ``cosqFFT''.

	  Error	codes:
	  -1: First argument not a real	array
	  -2: Second argument not integer
	  -3: Second argument out of range


  1.143.  remove



       [] = remove(fn)
	remove("file") removes the named file.
	  If the file does not exist or	some other error occurs,
	  no warning or	error message is given.
	  Error	codes:
	  1: Argument not a string






  1.144.  reshape



       [B] = reshape(A...)
	reshape(A,n,m,...) returns the data in array A rearranged
	  to have dimensionality n x m x ... . The product of the indices
	  must equal the length	of A.
	  reshape(A,#(n,m...)) works also.
	  Error	codes:
	  -1: First argument not an array
	  -2: Later argument not an integer
	  -3: Product of dimensions does not equal the length of first argument
	  -4: Number of	input arguments	exceeds	MAXRANK
	  -5: Second arg is array but not integer vector






  1.145.  round



       [y] = round(x)
	round(x) returns the nearest integer.
	  x must be integer or real scalar or array. If	it is an array,
	  the operation	is applied componentwise.


       See also: ``floor'', ``ceil''.

	  Error	codes:
	  -1: Complex or nonnumeric input argument





  1.146.  run









  [output] = run(cmd; input)
   run("cmd","input") runs operating system (Unix) command
     "cmd", using contents of the second argument string as
     standard input. It	returns	the standard output of "cmd"
     as	a string.

     The form run("cmd") may be	used if	the command does not
     read standard input. The command is executed by /bin/sh.

     Error codes:
     -1: First argument	not a string
     -2: Second	argument not a string
     -3: Error with temporary file
     -4: Error with internal pipe
     -5: run not supported: OS does not	provide	unistd.h nor popen()
     -6: Executing the command failed
     -7: wait(2) returned error
     -8: pipe(2) returned error
     -9: cannot	fork(2)	a child	process






  1.147.  save



       [] = save(fn...)
	save("file") saves all variables in Tela workspace
	  in "file". Any previous contents of "file" is
	  overwritten. The data	are written as Scientific
	  Data Sets in HDF format.
	  save("file","var1","var2"...)	saves only the
	  specified variables. Notice that you have to give
	  the variable names as	strings.

	  Limitations (bugs): It is not	possible to save
	  local	variables, since they are not bound to
	  symbols. If you try, the global one, if any,
	  will be saved.



       See also: ``load'', ``export_matlab''.

	  Error	codes:
	  1: Too few arguments
	  2: Argument not a string or char
	  3: Unexpected	HDF error






  1.148.  sec



       [y] = sec(x)
	y = sec(x) is the secant function
	  sec(x) = 1/cos(x).


  1.149.  sformat



       [s] = sformat(formatstr...)
	sformat("format-string",arg1,arg2,...) is similar to format,
	  except that it does not output to stdout but returns a string
	  variable.


       See also: ``format'', ``fformat'', ``sprintf''.

	  Error	codes:
	  -1: First argument not a string or char





  1.150.  showcompiled



       [] = showcompiled(filename...)
	showcompiled("filename.ct",f1,f2,...) compiles functions
	  f1,f2,... to C-tela code, creating "filename.ct".
	  If no	suffix is given	in "filename", the suffix
	  ".ct"	will be	assumed.
	  showcompiled(f1,f2,...) displays on standard output.


       See also: ``t2ct''.

	  NOTE:	STILL UNDER DEVELOPMENT
	  Error	codes:
	  1: One of the	args is	not a Tela-function
	  2: Cannot open output	file






  1.151.  sign



       [y] = sign(x)
	y = sign(x) returns 1 if x>0, 0	if x==0, and -1	if x<0.
	  x must be real. If x is array, the operation is applied componentwise.


       See also: ``HeavisideTheta''.

	  Error	codes:
	  -1: Complex or nonnumeric input argument





  1.152.  sin




  [y] =	sin(x)
   y = sin(x) computes the sine	function of x.
     If	x is complex, the result is complex, otherwise real.
     The argument must be in radians.
     If	x is an	array, the operation is	applied	componentwise.





  1.153.  sinFFT



       [f] = sinFFT(u; dim)
	sinFFT(u) gives	the sine Fast Fourier Transform	of array u.
	  If u's rank is more than one,	the transform is computed
	  only along the first dimension (many independent 1D
	  transforms).

	  sinFFT(u,dim)	computes the FFT along the specified dimension.
	  The first dimension is labeled 1 and so on.

	  For vector u,	f=sinFFT(u) is equivalent with

	  n = length(u); f = zeros(n);
	  for (j=1; j<=n; j++)
	      f[j] = 2*sum(u*sin((1:n)*j*pi/(n+1)));

	  Note that sinFFT is the most efficient when n+1 is a product of
	  small	primes,	where n	is the transform length.



       See also: ``invsinFFT'',	``cosFFT'', ``sinqFFT'', ``cosqFFT'',
       ``realFFT'', ``FFT''.

	  Error	codes:
	  -1: First argument not a real	array
	  -2: Second argument not integer
	  -3: Second argument out of range






  1.154.  sinh



       [y] = sinh(x)
	y = sinh(x) computes the hyperbolic sine function of x.
	  If x is complex, the result is complex, otherwise real.
	  If x is an array, the	operation is applied componentwise.





  1.155.  sinqFFT





  [f] =	sinqFFT(u; dim)
   sinqFFT computes the	quarter-wave sine Fourier transform of array u.
     Except for	the quarter-wave sine character, it works similarly to sinFFT.

     For vector	u, f=sinqFFT(u)	is equivalent with

     n = length(u); f =	zeros(n);
     for (j=1; j<=n; j++)
	 f[j] =	(-1)^(j-1)*u[n]	+ 2*sum(u[1:n-1]*sin((2*j-1)*(1:n-1)*pi/(2*n)));

     sinqFFT is	most efficient when the	transform length is a product
     of	small primes.



  See also: ``invsinqFFT'', ``realFFT'', ``cosqFFT'', ``FFT''.

     Error codes:
     -1: First argument	not a real array
     -2: Second	argument not integer
     -3: Second	argument out of	range






  1.156.  size



       [...] = size(x)
	[n,m,...] = size(A) finds out the dimensions of	array A.
	  The number of	n,m... must not	exceed rank(A).	If rank(A)==0
	  (that	is, A is scalar), n=size(A) sets 1 to n.
	  V = size(A) assigns the dimension vector [n,m,..] to V.
	  If A is scalar, V is set to 1, if A is vector, V becomes
	  a one-element	vector.


       See also: ``length'', ``rank''.

	  Error	codes:
	  -1: No output	arguments
	  -2: Argument has undefined value
	  1: More than one output arg but non-array input arg
	  2: Too many output args relative to input arg	rank





  1.157.  smenu



       [result]	= smenu(title...)
	choice = smenu("title","choice1","choice2",...)	displays
	  a menu of choices and	returns	the "choice" string corresponding
	  to the number	entered	by the user.


       See also: ``menu''.



     Error codes:
     -1: Less than two input args





  1.158.  sort



       [y;I] = sort(x)
	sort(x)	returns	array x	sorted in ascending order.
	  If x is complex, it is sorted	by the real parts.
	  If x is not an array,	it is returned as is.
	  [y,I]	= sort(x) returns also an index	vector I such that
	  y == x[I].

	  To sort with user-defined comparisons, do the	following.
	  For example, if you want to sort a complex vector z by
	  absolute value as Matlab does, first sort a vector of
	  absolute values saving the index information:

	  [y,I]	= sort(abs(z));

	  Then y=z[I] is the wanted result.

	  If x is multidimensional, it is implicitly flattened.





  1.159.  source



       [] = source(fn)
	source("file.t") loads the tela	code from given	file.


       See also: ``source_silent'', ``autosource'', ``load''.

	  Error	codes:
	  1: Operation did not succeed
	  2: Argument not a string





  1.160.  source_silent



       [] = source_silent(fn)
	source_silent("file.t")	is similar to source("file.t"),
	  but it does not complain if e.g. the file does not exist.


       See also: ``source'', ``autosource'', ``load''.

	  Error	codes:
	  1: Argument not a string


  1.161.  sprintf



       [s] = sprintf(formatstr,arg)
	sprintf("format-string",arg1,arg2,...) is an interface to the C
	  sprintf function. The	format string should have a percent
	  slot for every arg. The args may be integer or real scalars
	  or strings.


       See also: ``sformat''.


	  LIMITATIONS:
	      This implementation allows only one arg (arg1).
	      The resulting string may not become larger than
		  500 chars or Tela may	crash.
	  Error	codes:
	  -1: First arg	not a string
	  -2: Args may only be scalar ints or reals, or	strings






  1.162.  sqrt



       [y] = sqrt(x)
	y = sqrt(x) computes the square	root of	x.
	  If x is complex, the result is complex. If x is real or
	  integer, but negative, the result is complex (purely
	  imaginary). If x is real or integer and non-negative,
	  the result is	real.
	  If x is an array, the	operation is applied componentwise.
	  If some of the components are	negative, all components
	  of the result	are complex.





  1.163.  str2num



       [y] = str2num(s)
	str2num(s) converts a string to	a number.
	  The string must represent a scalar. If an error
	  occurs, str2num returns a void value.
	  Error	codes:
	  1: Argument not a string or char





  1.164.  streq





  [y] =	streq(s1,s2)
   streq("string1","string2") returns 1	if the argument
     strings are exactly equal and 0 otherwise.	If one of
     the args is not a string, the result is also 0.


  See also: ``strstarteq''.



  1.165.  strmat



       [x] = strmat(...)
	strmat("string1","string2",...)	makes a	string matrix
	  ouf of individual strings. The strings need not be same length,
	  they are padded with zeros (invisible) if they are not.


       See also: ``strmat2''.

	  Error	codes:
	  -1: Argument not a string





  1.166.  strmat2



       [x] = strmat2(str; sep)
	strmat2("string") creates a string matrix from "string"
	  interpreting the newline character as	row ending marker.
	  strmat2("string",sep)	uses separator sep instead of
	  newline char;	sep may	be either character or string.
	  If sep is a string, any character that is a member of	sep
	  is taken to be a separator. If the rows have unequal lengths,
	  they are padded with zeros.


       See also: ``strmat''.

	  Error	codes:
	  -1: First arg	not a string
	  -2: Second arg not a char or string






  1.167.  strstarteq



       [y] = strstarteq(s1,s2)
	strstarteq("string1","string2")	returns	1 if the argument
	  strings are equal on the first min(length(s1),length(s2))
	  characters and 0 otherwise.
	  If one of the	the args is not	a string, the result is	also 0.



  See also: ``streq''.



  1.168.  sum



       [y] = sum(x;d)
	sum(x) sums all	the elements of	x, if x	is an array.
	  The result type is always the	same as	the component type
	  of x.	If x is	scalar,	it is returned as such.
	  sum(x,d) sums	only along d'th	dimension, returning array
	  of rank one less than	rank(x).


       See also: ``cumsum'', ``prod''.

	  Error	codes:
	  -1: Nonnumeric input arg
	  -2: Second argument not an integer
	  -3: Second argument (dimension spec) out of range





  1.169.  system



       [] = system(s)
	system("string") executes string as an external	operating system
	  (Unix) command.
	  Error	codes:
	  1: Argument not a string or char





  1.170.  t2ct



       [] = t2ct(fn)
	t2ct("filename.t") translates t-code to	ct-code.
	  Error	codes:
	  1: Operation did not succeed
	  2: Argument not a string
	  3: Could not open output file






  1.171.  tan








  [y] =	tan(x)
   y = tan(x) computes the tangent function of x.
     If	x is complex, the result is complex, otherwise real.
     The argument must be in radians.
     If	x is an	array, the operation is	applied	componentwise.





  1.172.  tanh



       [y] = tanh(x)
	y = tanh(x) computes the hyperbolic tangent function of	x.
	  If x is complex, the result is complex, otherwise real.
	  If x is an array, the	operation is applied componentwise.





  1.173.  telapath



       [s] = telapath()
	telapath() returns the currently set effective Tela path
	  as a string.





  1.174.  tic



       [] = tic()
	tic() marks the	CPU time at which it was invoked.
	  To measure CPU time, use tic() and toc().


       See also: ``cputime'', ``toc''.

	  Example:

	     a = rand(100,100);	tic(); b=inv(a); toc()

	 This would measure the	CPU time in inverting a	100x100
	 random	real matrix. See also: toc.





  1.175.  toc



       [t] = toc()
	toc() gives the	CPU seconds used since the last	call to	tic().



  See also: ``tic'', ``cputime''.



  1.176.  tostring



       [y] = tostring(x)
	tostring(x) converts an	integer	vector to a string.
	  Transfer of characters is stopped if zero element
	  is encountered.
	  tostring(A) where A is geneeral integer array	copies
	  A and	sets the string	flag.
	  Error	codes:
	  -1: Argument not an integer array






  1.177.  transpose



       [B] = transpose(A; P)
	B = transpose(A) returns a transpose of	array A: B[i,j,k...l] =	A[l...k,j,i].
	  B = transpose(A,P) where P is	integer	vector transposes the indices in the
	  permutation defined by P.
	  For example if A has rank 3, B = transpose(A,[2,1,3])	causes the assignment
	  B[j,i,k] = A[i,j,k] to be carried out. B = transpose(A) would	in this	case
	  correspond to	B[k,j,i] = A[i,j,k].

	  You can abbreviate "transpose(A)" by "A.'".


       See also: ``herm''.

	  Error	codes:
	  -1: Permutation argument not integer array
	  -2: Permutation argument of bad rank or size
	  -3: Permutation argument contains invalid integers





  1.178.  unhide



       [] = unhide(...)
	hide("sym-name",...) unsets the	'hidden' attribute to
	  specified symbols.


       See also: ``whos'', ``hide''.

	  Error	codes:
	  1: Argument not a string
	  2: Argument does not name a symbol




  1.179.  version



       [x] = version()
	version() returns the Tela version number (real) currently
	  in use.





  1.180.  vplot



       [] = vplot(x,y,vx,vy...)
	vplot(x,y,vx,vy[,options]) produces a 2D vector	plot of	the vector
	  field	(vx,vy). All arguments x,y,vx and vy must be 2D	integer	or
	  real arrays and of the same size. Each 2D vector will	be positioned
	  at (x[i,j],y[i,j]) and its direction will be (vx[i,j],vy[i,j]) where
	  (i,j)	run over rows and columns of the matrices.


       See also: ``annotate'', ``plot'', ``mesh'', ``contour'',	``pcolor''.

	  Error	codes:
	  1: Could not open temporary MTV file
	  2: One of first four args is not a numeric array
	  3: One of first four args has	rank not equal to 2
	  4: Dimensions	of first four args disagree
	  5: Syntax error in graph options





  1.181.  whos



       [] = whos(;hidden)
	whos() displays	names of variables together with their
	  types	and values, if short. 'Hidden' symbols are not shown.
	  whos("hidden") shows also hidden symbols.


       See also: ``hide'', ``unhide''.

	  Error	codes:
	  1: Bad argument















