response_coefficients.m

％The Metabolic Networks Toolbox contains functions to create, ％modify, display, and simulate bioche

function [RS,RJ,RS_2,RJ_2] = response_coefficients(CS,epsilon_1,pi_1,epsilon_2,rho_2,pi_2,split)

%[RS,RJ,RS_2,RJ_2] = response_coefficients(CS,epsilon_1,pi_1,epsilon_2,rho_2,pi_2)
%
% calculate the response coefficients of first and second order

n_react = size(epsilon_1,1);

CJ    = epsilon_1 * CS + eye(n_react);

RS    = CS * pi_1;
RJ    = CJ * pi_1;

  if nargout>2,
    Gamma =  ...
	tensor_product(tensor_product(epsilon_2,RS),RS,2,1) ...
	+ tensor_product(rho_2,RS,2,1) ...
	+ permute(tensor_product(rho_2,RS,2,1),[1,3,2])...
	+ pi_2;
    
    RS_2 =   tensor_product(CS,Gamma);
    RJ_2 =   tensor_product(CJ,Gamma);
  end