%dev_qw_my.m: Procedure to evaluate derivative of the expected value
%function at a point (w,c).
%Hugo Benitez, Yale University, 1999.

function[x]=dev_qw_my1(c);
ev_qw_myh=@ev_qw_my1;
global ddelta wmax wgrid i;
if c-ddelta<0;
    x=(feval(ev_qw_myh,c+3*ddelta)-feval(ev_qw_myh,c+ddelta))/(2*ddelta);
elseif abs(wgrid(i)-wmax)<ddelta;
    x=(feval(ev_qw_myh,c-1*ddelta)-feval(ev_qw_myh,c-3*ddelta))/(2*ddelta);
else;
    x=(feval(ev_qw_myh,c+ddelta)-feval(ev_qw_myh,c-ddelta))/(2*ddelta);
end;