From 277d1edfa17bf3719d90ddbac8e31f6181e952c3 Mon Sep 17 00:00:00 2001
From: Sandeep Gupta
Date: Sun, 18 Jun 2017 23:55:40 +0530
Subject: First commit
---
src/c/differential_calculus/ode/dodes.c | 49 +++++++++++++++++++++++++++++++++
1 file changed, 49 insertions(+)
create mode 100644 src/c/differential_calculus/ode/dodes.c
(limited to 'src/c/differential_calculus/ode/dodes.c')
diff --git a/src/c/differential_calculus/ode/dodes.c b/src/c/differential_calculus/ode/dodes.c
new file mode 100644
index 00000000..6d1a8672
--- /dev/null
+++ b/src/c/differential_calculus/ode/dodes.c
@@ -0,0 +1,49 @@
+/* Copyright (C) 2016 - IIT Bombay - FOSSEE
+
+ This file must be used under the terms of the CeCILL.
+ This source file is licensed as described in the file COPYING, which
+ you should have received as part of this distribution. The terms
+ are also available at
+ http://www.cecill.info/licences/Licence_CeCILL_V2-en.txt
+ Author: Siddhesh Wani
+ Organization: FOSSEE, IIT Bombay
+ Email: toolbox@scilab.in
+*/
+
+/*Function for solving ODEs using GSL library*/
+
+#include "ode.h"
+#include "types.h"
+#include <gsl/gsl_errno.h>
+#include <gsl/gsl_matrix.h>
+#include <gsl/gsl_odeiv2.h>
+
+
+double dodes(double initial_value, double start_time, double end_time, \
+ int (*ode_function)(double, double*, double*, int*), \
+ char *solver_type, double nequs, double eps_abs, \
+ double eps_rel, double step_size, int *params)
+{
+ double out = 0, t = 0;
+ //int status;
+ out = initial_value;
+ t = start_time;
+ //Setup ODE related parameters
+ gsl_odeiv2_system sys = {ode_function, NULL, nequs, NULL};
+
+ gsl_odeiv2_step *s = gsl_odeiv2_step_alloc (gsl_odeiv2_step_rkf45, nequs);
+ gsl_odeiv2_control *c = gsl_odeiv2_control_y_new (eps_abs, eps_rel);
+ gsl_odeiv2_evolve *e = gsl_odeiv2_evolve_alloc (nequs);
+
+ while(t < end_time)
+ {
+ gsl_odeiv2_evolve_apply_fixed_step (e, c, s, &sys, &t, step_size, &out);
+ }
+
+ gsl_odeiv2_evolve_free (e);
+ gsl_odeiv2_control_free (c);
+ gsl_odeiv2_step_free (s);
+
+ return out;
+
+}
--
cgit