ne_dyn_node_ode_lib.c

/*===========================================================================
 NetEvo Foundation Library
 Copyright (C) 2009, 2010 Thomas E. Gorochowski <tgorochowski@me.com>
 Bristol Centre for Complexity Sciences, University of Bristol, Bristol, UK
 ---------------------------------------------------------------------------- 
 NetEvo is a computing framework designed to allow researchers to investigate 
 evolutionary aspects of dynamical complex networks. By providing tools to 
 easily integrate each of these factors in a coherent way, it is hoped a 
 greater understanding can be gained of key attributes and features displayed 
 by complex systems.
 
 NetEvo is open-source software released under the Open Source Initiative 
 (OSI) approved Non-Profit Open Software License ("Non-Profit OSL") 3.0. 
 Detailed information about this licence can be found in the COPYING file 
 included as part of the source distribution.
 
 This library is distributed in the hope that it will be useful, but
 WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 ============================================================================*/


#include "ne_dyn_node_ode_lib.h"


ne_dyn_node_t * ne_dyn_ode_n1_none_alloc (void)
{
   ne_dyn_node_t *nodeDyn;
   
   if ((nodeDyn = (ne_dyn_node_t *)malloc(sizeof(ne_dyn_node_t))) == NULL) {
      ne_error("ne_dyn_ode_n1_none_alloc: Could not allocate memory.");
      return NULL;
   }
   
   /* Define the dynamics structure */
   nodeDyn->name   = "ODE_N1_NONE";
   nodeDyn->states = 1;
   nodeDyn->fn     = &ne_dyn_ode_n1_none_fn;
   return nodeDyn;
}


ne_err_code_t ne_dyn_ode_n1_none_fn (int i, void *S, double t, const double *y, double *dydt, 
                            double *params)
{
   dydt[i] = 0.0;
   return NE_SUCCESS;
}


ne_dyn_node_t * ne_dyn_ode_n3_rossler_alloc (void)
{
   ne_dyn_node_t *nodeDyn;
   
   if ((nodeDyn = (ne_dyn_node_t *)malloc(sizeof(ne_dyn_node_t))) == NULL) {
      ne_error("ne_dyn_ode_n3_rossler_alloc: Could not allocate memory.");
      return NULL;
   }
   
   /* Define the dynamics structure */
   nodeDyn->name   = "ODE_N3_ROSSLER";
   nodeDyn->states = 3;
   nodeDyn->fn     = &ne_dyn_ode_n3_rossler_osc_fn;
   return nodeDyn;
}


ne_err_code_t ne_dyn_ode_n3_rossler_osc_fn (int i, void *S, double t, const double *y, double *dydt, 
                                 double *params)
{
   int xInd, yInd, zInd;
   
   /* Precalculate index for xi, yi, zi components */
   xInd = i*3;
   yInd = (i*3)+1;
   zInd = (i*3)+2;
   
   /* Calculate derivite values */
   dydt[xInd] = -y[yInd] - y[zInd];
   dydt[yInd] = y[xInd] + (params[0] * y[yInd]);
   dydt[zInd] = params[1] + ((y[xInd] - params[2]) * y[zInd]);
   
   return NE_SUCCESS;   
}