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#include <stdio.h>
#include <math.h>
#include <arkode/arkode.h> /* prototypes for ARKODE fcts., consts. */
#include <nvector/nvector_serial.h> /* serial N_Vector types, fcts., macros */
#include <sunmatrix/sunmatrix_dense.h> /* access to dense SUNMatrix */
#include <sunlinsol/sunlinsol_dense.h> /* access to dense SUNLinearSolver */
#include <arkode/arkode_direct.h> /* access to ARKDls interface */
#include <sundials/sundials_types.h> /* definition of type realtype */
#include <sundials/sundials_math.h>
#include "farkode.h"
#include <HsFFI.h>
#include "Main_stub.h"
/* Check function return value...
opt == 0 means SUNDIALS function allocates memory so check if
returned NULL pointer
opt == 1 means SUNDIALS function returns a flag so check if
flag >= 0
opt == 2 means function allocates memory so check if returned
NULL pointer
*/
int check_flag(void *flagvalue, const char *funcname, int opt)
{
int *errflag;
/* Check if SUNDIALS function returned NULL pointer - no memory allocated */
if (opt == 0 && flagvalue == NULL) {
fprintf(stderr, "\nSUNDIALS_ERROR: %s() failed - returned NULL pointer\n\n",
funcname);
return 1; }
/* Check if flag < 0 */
else if (opt == 1) {
errflag = (int *) flagvalue;
if (*errflag < 0) {
fprintf(stderr, "\nSUNDIALS_ERROR: %s() failed with flag = %d\n\n",
funcname, *errflag);
return 1; }}
/* Check if function returned NULL pointer - no memory allocated */
else if (opt == 2 && flagvalue == NULL) {
fprintf(stderr, "\nMEMORY_ERROR: %s() failed - returned NULL pointer\n\n",
funcname);
return 1; }
return 0;
}
/* f routine to compute the ODE RHS function f(t,y). */
int f(realtype t, N_Vector y, N_Vector ydot, void *user_data)
{
realtype *rdata = (realtype *) user_data; /* cast user_data to realtype */
realtype lamda = rdata[0]; /* set shortcut for stiffness parameter */
realtype u = NV_Ith_S(y,0); /* access current solution value */
/* fill in the RHS function: "NV_Ith_S" accesses the 0th entry of ydot */
NV_Ith_S(ydot,0) = lamda*u + 1.0/(1.0+t*t) - lamda*atan(t);
return 0; /* return with success */
}
int FARK_IMP_FUN(realtype *T, realtype *Y, realtype *YDOT,
long int *IPAR, realtype *RPAR, int *IER) {
multiEq(T, Y, YDOT, IPAR, RPAR, IER);
return 0;
}
/* C interface to user-supplied FORTRAN function FARKIFUN; see
farkode.h for further details */
int FARKfi(realtype t, N_Vector y, N_Vector ydot, void *user_data) {
int ier;
realtype *ydata, *dydata;
FARKUserData ARK_userdata;
ydata = N_VGetArrayPointer(y);
dydata = N_VGetArrayPointer(ydot);
ARK_userdata = (FARKUserData) user_data;
FARK_IMP_FUN(&t, ydata, dydata, ARK_userdata->ipar,
ARK_userdata->rpar, &ier);
return(ier);
}
/* Jacobian routine to compute J(t,y) = df/dy. */
int Jac(realtype t, N_Vector y, N_Vector fy, SUNMatrix J,
void *user_data, N_Vector tmp1, N_Vector tmp2, N_Vector tmp3)
{
realtype *rdata = (realtype *) user_data; /* cast user_data to realtype */
realtype lamda = rdata[0]; /* set shortcut for stiffness parameter */
realtype *Jdata = SUNDenseMatrix_Data(J);
/* Fill in Jacobian of f: set the first entry of the data array to set the (0,0) entry */
Jdata[0] = lamda;
return 0; /* return with success */
}
/* check the computed solution */
int check_ans(N_Vector y, realtype t, realtype rtol, realtype atol)
{
int passfail=0; /* answer pass (0) or fail (1) flag */
realtype ans, err, ewt; /* answer data, error, and error weight */
realtype ONE=RCONST(1.0);
/* compute solution error */
ans = atan(t);
ewt = ONE / (rtol * SUNRabs(ans) + atol);
err = ewt * SUNRabs(NV_Ith_S(y,0) - ans);
/* is the solution within the tolerances? */
passfail = (err < ONE) ? 0 : 1;
if (passfail) {
fprintf(stdout, "\nSUNDIALS_WARNING: check_ans error=%g \n\n", err);
}
return(passfail);
}
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