%function x = symspace(arg1,n,arg2)
%
%    Title: SYMmetric linearly SPACEd vector
%
% For two input arguments:
%
%  Purpose: Generates a row vector of linearly spaced points
%	    between -xmax and xmax with 0 at the center. 
%	    i.e., of the form: 
%
%		x = [-xmax .... 0 .... +xmax]   	(if n is odd)
%		x = [-xmax+delta .... 0 .... +xmax] 	(if n is even)
%
%    Input: arg1 = xmax = |range(x)|
%	       n = number of points to generate
%
% For three input arguments:
%
%  Purpose: Generates a row vector of linearly spaced points
%	    between x0-dx and x0+dx with x0 at the center. 
%	    i.e., of the form: 
%
%		x = [x0-dx .... x0 .... x0+dx]   	(if n is odd)
%		x = [x0-dx+delta .... x0 .... x0+dx] 	(if n is even)
%
%    Input: arg1 = dx
%	       n = number of points to generate
%	    arg2 = x0
%
%    Notes: Similar in concept to MATLAB's linspace.m
%
function x = symspace(arg1,n,arg2)

% Defaults

if(nargin<2),n=64;end;

% Make sure n is even

  nn = n - odd(n);
npts = nn/2+1;

if(nargin<=2),
	xmax = arg1;
	xa = linspace(-xmax,0,npts);
	xb = linspace(0,xmax,npts);
	 x = [xa,xb(2:length(xb))];
	 x = x(1:length(x)-even(n));
elseif(nargin==3),
	x0 = arg2;
	dx = arg1;
	xmin = x0 - dx;
	xmax = x0 + dx;
	xa = linspace(xmin,x0,npts);
	xb = linspace(x0,xmax,npts);
	 x = [xa,xb(2:length(xb))];
	 x = x(1+even(n):length(x));
end