network_derivative.m

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

function f = network_derivative(t,s_int,network,internal,external,s_ext,N_int)

% vector f contains time derivative of the internal metabolites

 s(internal)  = s_int;
 s(external)  = s_ext;
 f            = N_int * network_velocities(s,network);