function [con,coneq]=nlc_tsrk(x,s,k,p,n) % Nonlinear constraints for SSP TSRK Methods % Including both order conditions and absolute monotonicity conditions %===================================================== % Extract arrays A,d,b,theta from x %Unpacking decision variables from x [A ,Ahat, B, Bhat, D, theta] = unpackexplicitT2(x, s, k); A= [zeros(k-1,s+k-1);Ahat,A]; b= [Bhat, B]; D= [eye(k);D]; z=-x(end); %Radius of absolute monotonicity %===================================================== %===================================================== % Absolute monotonicity conditions (from Spijker 2007) % Construct Spijker form S=[D;theta]; T=[A;b]; T=[T,zeros(s+k,1)]; con1=(eye(size(T,1))+z*T)\[S z*T]; con=-con1(:); %===================================================== % Order conditions s=length(A); coneq=oc_ksrk(s,k,p,n,A,D,b,theta); end % of function