forum.alglib.nethttp://forum.alglib.net/ Pass results of one variable of ODE solution into arrayhttp://forum.alglib.net/viewtopic.php?f=2&t=4474 Page 1 of 1

 Author: bisk [ Thu Sep 22, 2022 6:45 pm ] Post subject: Pass results of one variable of ODE solution into array So I use the MWE from manual. Only with the slight difference of adding to variables to solve, so that I get a 2d_array.Then , I need the solution of each variable seperately into an array to pass to other functions that use arrays. Thing is, this works in 1d_array as mentinoned below, but can't make it work with 2d array.Any idea/hints?Code:#include #include #include #include "diffequations.h"#include "stdafx.h"using namespace alglib;void ode_function_1_diff(const real_1d_array &y, double x, real_1d_array &dy, void *ptr) {    // this callback calculates f(y[],x)=-y[0]//CHANGE -> now it's two functions, f(y,x)=-y[0],-0.5y[0] so it actually returns [y[0] ,y[1]] on results    dy[0] = -y[0];    dy[1] = -0.5*y[0];}int main(int argc, char **argv){    real_1d_array y;    double _r1[] = {1, 3};    y.setcontent(2,_r1);    real_1d_array x = "[0, 1, 3]";    double eps = 0.00001;    double h = 0;    odesolverstate s;    ae_int_t m;    real_1d_array xtbl;    real_2d_array ytbl;    odesolverreport rep;    odesolverrkck(y, x, eps, h, s);    alglib::odesolversolve(s, ode_function_1_diff);    odesolverresults(s, m, xtbl, ytbl, rep);    printf("%d\n", int(m));     printf("%s\n", xtbl.tostring(2).c_str());     //double *test = double* xtbl    double* FC_array = &xtbl.getcontent()[0];  //CHANGE: THIS WORKS -> Can get 1d_array to normal Array and works well    printf("%f\n", FC_array[1]); // EXPECTED: [0, 1, 3]    printf("%f\n", xtbl.getcontent()[0]); // EXPECTED: [0, 1, 3]    printf("going to check 2d_array->array\n"); // here I Tried to do the same, for solution (and then figure out how to get only 1st itme of each row)//THIS DOESN'T WORK//double* F2C_array = &ytbl.getcontent()[0];  //    return 0;}

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