function c = fitfunexpc(lam, t, y)
% FITFUNEXPC - Used  by PRCPRR to return optimized fitted c.
%  FITFUNEXPC assumes a function of the form
%
%     y =  c(1)*exp(-lam(1)*t) + ... + c(n)*exp(-lam(n)*t)
%
%   with n linear parameters and n nonlinear parameters.
%
% Use as:
%   lam = leastsq('fitfunexp', [1 0]', [0 1e-3 0 0 1], [], x, y); 
%   c   = fitfunexpc(lam, x, y);
%   yf  = funexp(lam, c, xf); 

A = zeros(length(t),length(lam));
for j = 1:size(lam)
   A(:,j) = exp(-lam(j)*t);
end

c = A\y;