function [A, fz] = calculate_derivatives(f,v)
% [A fz] = calculate_derivatives(f,v)
%
%     calculates the derivatives of a vector function f(x) at the point x = v.
%
%     f is the function handle
%     v is the input vector
%
%  Output:
%     A is the array of partial derivatives a(i,j) = partial f(i) / partial v(j)
%     fz is the vector returned by fz = f(v)

%  Written by: John S. Loomis
%  Revised:  6 Feb 2003

fz = f(v);
nv = length(v);
nd = length(fz);
delta = 1e-5;
A = zeros(nd,nv);
for j=1:nv
    vsave = v(j);
    v(j) = vsave+delta;
    fp = f(v);
    v(j) = vsave-delta;
    fn = f(v);
    A(:,j)=(fp-fn)/(2*delta);
    v(j)=vsave;
end

Published with MATLAB® 7.6