% listing of the file "kin3F.m" used by file "kin3.m"

% Define the relationship between the value q (see last line)
% and kin3F and the initial guess vector g.
% These are all arbitrary names.
% The value of q is what fminsearch minimizes.

function q = kin3F(g);

% declare global variables used by kin3.m and kin3F.m

global rexp cA cB

% pull kf, kr, KA, KB out of the parameter value guess vector g

kf = g(1);
kr = g(2);
KA = g(3);
KB = g(4);

% compute the "calculated" rate, rcalc

% dot . needed before / since numerator and denominator are
% matrices and you don't want matrix division, just
% division of individual elements in the matrices
% dot . NOT needed before the * here since k, KA, KB are scalars

rcalc = (kf * cA - kr * cB) ./ (1 + KA * cA + KB * cB);

error = (rexp - rcalc);

q = sum(error .^ 2);