integrator.c File Reference

specific dirdyn function for the integrators More...

#include "integrator.h"
#include "mbs_dirdyn_struct.h"
#include "mbs_rk4.h"
#include "mbs_dopri5.h"
#include "mbs_euler_explicit.h"
#include "mbs_euler_implicit.h"
#include "mbs_rosenbrock.h"
#include "mbs_custom.h"
#include "mbs_bader.h"
#include "mbs_w_methods.h"
#include "mbs_message.h"

Functions
int	mbs_estim_jac_acc (double x, double htry, double y[], double dydx[], int compute_dfdx, double dfdx[], double **dfdy, int n, int(*derivs)(double, double[], double[], MbsData *, MbsDirdyn *), MbsData *s, MbsDirdyn *dd)
	Evaluate the Jacobian of a function accelerations using finite difference. More...
int	mbs_freeze_jac (int freeze_index, int *next_freeze_index, double x, double h, double y[], double dydx[], int compute_dfdx, double dfdx[], double **dfdy, double dydx_freeze[], double dfdx_freeze[], double **dfdy_freeze, int n, int(*derivs)(double, double[], double[], MbsData *, MbsDirdyn *), MbsData *s, MbsDirdyn *mbs_dd)
	Freeze the Jacobian of an integrator structure until mbs_dd->options->n_freeze. More...
void	set_integrator (MbsDirdyn *mbs_dd)
	Set the function pointer in MbsDirdyn. More...
void	print_warnings_integrator (MbsData *mbs_data, MbsDirdyn *mbs_dd, int type_of_integrator)
	Check the options set by user to warn him when he modified an unused option for the integrator. More...
void	print_warnings_constant_step_integrator (MbsDirdyn *mbs_dd, char *integrator_name)
	Print the warning message, called by print_warnings_integrator for constant step size dt integrators. More...

Detailed Description

specific dirdyn function for the integrators

Creation date: May 2015

Author

Olivier Lantsoght

Modification date: June 2018 \modified by Sebastien Timmermans

(c) Universite catholique de Louvain

Function Documentation

mbs_estim_jac_acc()

int mbs_estim_jac_acc	(	double	x,
		double	htry,
		double	y[],
		double	dydx[],
		int	compute_dfdx,
		double	dfdx[],
		double **	dfdy,
		int	n,
		int(*)(double, double[], double[], MbsData *, MbsDirdyn *)	derivs,
		MbsData *	s,
		MbsDirdyn *	dd
	)

Evaluate the Jacobian of a function accelerations using finite difference.

Modify and do not restore dydx. WARNING: All vector/matrix indexes start at 0! Update the value of dfdx and dfdy.

Parameters

x	current time value, at which the function needs to be computed
htry	time step
y	state vector of variable
compute_dfdx	flag to ON to compute the dfdx terms, default = 1 ; if compute_dfdx = 0 => dfdx is filled with zeroes
dydx	derivative of y by x
dfdx	derivative of f by x
dfdy	derivative of f by y
n	number of variables
derivs	the function computing f'
s	the MbsData structure of the model on which dirdyn analysis is computed.
dd	the MbsDirdyn structure related to the integration.

Returns

Error status, <0 in case of failure.

mbs_freeze_jac()

int mbs_freeze_jac	(	int	freeze_index,
		int *	next_freeze_index,
		double	x,
		double	h,
		double	y[],
		double	dydx[],
		int	compute_dfdx,
		double	dfdx[],
		double **	dfdy,
		double	dydx_freeze[],
		double	dfdx_freeze[],
		double **	dfdy_freeze,
		int	n,
		int(*)(double, double[], double[], MbsData *, MbsDirdyn *)	derivs,
		MbsData *	s,
		MbsDirdyn *	mbs_dd
	)

Freeze the Jacobian of an integrator structure until mbs_dd->options->n_freeze.

WARNING: All vector/matrix indexes start at 0!

Parameters

freeze_index	current count of refreezing steps (if 0, recompute Jac)
next_freeze_index	[out] pointor to next refreezing step
x	current time value, at which the function needs to be computed
h	time step
y	state vector of variable
dydx	derivative of y by x
compute_dfdx	flag to ON to compute the dfdx terms, default = 1 ; if compute_dfdx = 0 => dfdx is filled with zeroes
dfdx	derivative of f by x
dfdy	derivative of f by y
dydx_freeze	pointor to freezed derivative of y by x
dfdx_freeze	pointor to freezed derivative of f by x
dfdy_freeze	pointor to freezed derivative of f by y
n	number of variables
derivs	the function computing f'
s	the MbsData structure of the model on which dirdyn analysis is computed.
mbs_dd	the MbsDirdyn structure related to the integration.

Returns

Error status, <0 in case of failure.

print_warnings_constant_step_integrator()

void print_warnings_constant_step_integrator	(	MbsDirdyn *	mbs_dd,
		char *	integrator_name
	)

Print the warning message, called by print_warnings_integrator for constant step size dt integrators.

Parameters

mbs_dd	MbsDirdyn structure
integrator_name	string to print in the warning message, corresponding to the integrator (RK4, EulerEx, ...)

print_warnings_integrator()

void print_warnings_integrator	(	MbsData *	mbs_data,
		MbsDirdyn *	mbs_dd,
		int	type_of_integrator
	)

Check the options set by user to warn him when he modified an unused option for the integrator.

Parameters

mbs_data	MbsData structure
mbs_dd	MbsDirdyn structure
type_of_integrator	ID if the used integrator (RK4, Dopri5...)

set_integrator()

void set_integrator

(

MbsDirdyn *

dd

)

Set the function pointer in MbsDirdyn.

Parameters

dd	MbsDirdyn structure to adapt