function [out,w,wi,rc] = instamix( in, b)
% Return an arbitrarily conditioned mix and mixing matrix
%
%  Usage:
%    [out,w,wi,rc] = instamix( in, b)
%
%  Inputs:
%    in: the input sources, one in each row
%    b: an indication of the mixing matrix condition (0 = singular matrix)
%
%  Outputs:
%    out: the resulting mix
%    w: the mixing matrix
%    wi: the inverse of the mixing matrix
%    rc: the reciprocal condition number of the mixing matrix
%
%  If only one output is requested, w is returned

% Default condition
if nargin == 1
	b = .5;
end

% Get the matrix
[r,c] = size( in);
w = ones( r, r);
w = w + diag( r * b * ones( r, 1));

% Decide what to send out
if nargout < 2
	out = w;
else
	out = w * in;
end

% Provide inverse of mixing matrix if asked to
if nargout > 2
	wi = inv( w);
end

% Ditto for reciprocal condition number
if nargout == 4
	rc = rcond( w);
end