/* nag_ode_ivp_rk_errass (d02pzc) Example Program. * * Copyright 1992 Numerical Algorithms Group. * * Mark 3, 1992. * Mark 7 revised, 2001. * Mark 8 revised, 2004. * */ #include #include #include #include #include #include #ifdef __cplusplus extern "C" { #endif static void f(Integer neq, double t1, double y[], double yp[], Nag_User *comm); #ifdef __cplusplus } #endif #define NEQ 4 #define ZERO 0.0 #define ONE 1.0 #define THREE 3.0 #define ECC 0.7 int main(void) { Integer exit_status=0, i, neq; NagError fail; Nag_ErrorAssess errass; Nag_ODE_RK opt; Nag_RK_method method; Nag_User comm; double errmax, hstart, pi, *rmserr=0, tend, terrmx, tgot, *thres=0, tol; double tstart, twant, *ygot=0, *ymax=0, *ypgot=0, *ystart=0; INIT_FAIL(fail); Vprintf("nag_ode_ivp_rk_errass (d02pzc) Example Program Results\n"); /* Set initial conditions and input for nag_ode_ivp_rk_setup (d02pvc) */ neq = NEQ; if (neq>=1) { if ( !( thres = NAG_ALLOC(neq, double)) || !( ygot = NAG_ALLOC(neq, double)) || !( ypgot = NAG_ALLOC(neq, double)) || !( ystart = NAG_ALLOC(neq, double)) || !( ymax = NAG_ALLOC(NEQ, double)) || !( rmserr = NAG_ALLOC(NEQ, double)) ) { Vprintf("Allocation failure\n"); exit_status = -1; goto END; } } else { exit_status = 1; return exit_status; } /* nag_pi (x01aac). * pi */ pi = X01AAC; tstart = ZERO; ystart[0] = ONE - ECC; ystart[1] = ZERO; ystart[2] = ZERO; ystart[3] = sqrt((ONE+ECC)/(ONE-ECC)); tend = THREE*pi; for (i=0; i