FGRungeKutta Class Reference

Detailed Description

Abstract base.

Definition at line 78 of file FGRungeKutta.h.

#include <FGRungeKutta.h>

Inheritance diagram for FGRungeKutta:

Collaboration diagram for FGRungeKutta:

Public Types
enum	eStates {   eNoError =0 , eMathError =1 , eFaultyInit =2 , eEvolve =4 ,   eUnknown =8 }

Public Member Functions
void	clearStatus ()
double	evolve (double y_0, FGRungeKuttaProblem *pf)
double	getError ()
int	getIterations ()
int	getStatus ()
double	getXEnd ()
int	init (double x_start, double x_end, int intervals=4)
void	setTrace (bool t)

Protected Attributes
double	err
double	h
double	h05
FGRungeKuttaProblem *	pfo

Member Enumeration Documentation

eStates

enum eStates

Definition at line 82 of file FGRungeKutta.h.

{ eNoError=0, eMathError=1, eFaultyInit=2, eEvolve=4, eUnknown=8} ;

Constructor & Destructor Documentation

FGRungeKutta()

FGRungeKutta ( )

inlineprotected

Definition at line 98 of file FGRungeKutta.h.

:  status(eNoError), trace_values(false), iterations(0) {};

~FGRungeKutta()

~FGRungeKutta ( )

protectedvirtual

Definition at line 52 of file FGRungeKutta.cpp.

{ };

Member Function Documentation

clearStatus()

void clearStatus ( )

inline

Definition at line 93 of file FGRungeKutta.h.

{ status = eNoError; }

evolve()

double evolve	(	double	y_0,
		FGRungeKuttaProblem *	pf
	)

Definition at line 87 of file FGRungeKutta.cpp.

{
  double x = x0;
  double y = y_0;
  pfo = pf;
 
  iterations = 0;
 
  if (!trace_values) {
    while (x<safer_x1) {
      y  = approximate(x,y);
      if (!sane_val(y)) { status &= eMathError; }
      x += h;
      iterations++;
    }
  } else {
    FGLogging log(LogLevel::DEBUG);
    while (x<safer_x1) {
      log << x << " " << y << "\n";
      y = approximate(x,y);
      if (!sane_val(y)) { status &= eMathError; }
      x += h;
      iterations++;
    }
    log << x << " " << y << "\n";
  }
 
  x_end = x; // twimc, store the last x used.
  return y;
}

getError()

double getError ( )

inline

Definition at line 89 of file FGRungeKutta.h.

{ return err; }

getIterations()

int getIterations ( )

inline

Definition at line 92 of file FGRungeKutta.h.

{ return iterations; }

getStatus()

int getStatus ( )

inline

Definition at line 91 of file FGRungeKutta.h.

{ return status; }

getXEnd()

double getXEnd ( )

inline

Definition at line 88 of file FGRungeKutta.h.

{ return x_end; }

init()

int init	(	double	x_start,
		double	x_end,
		int	intervals = 4
	)

Definition at line 54 of file FGRungeKutta.cpp.

{
  x0 = x_start;
  x1 = x_end;
  h  = (x_end - x_start)/intervals;
  safer_x1 = x1 - h*1e-6; // avoid 'intervals*h < x1'
  h05 = h*0.5;
  err = 0.0;
 
  if (x0>=x1) {
    status &= eFaultyInit;
  }
  return status;
}

setTrace()

void setTrace ( bool  t )

inline

Definition at line 94 of file FGRungeKutta.h.

{ trace_values = t; }

Member Data Documentation

err

double err

protected

Definition at line 105 of file FGRungeKutta.h.

h

double h

protected

Definition at line 103 of file FGRungeKutta.h.

h05

double h05

protected

Definition at line 104 of file FGRungeKutta.h.

pfo

FGRungeKuttaProblem* pfo

protected

Definition at line 101 of file FGRungeKutta.h.

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The documentation for this class was generated from the following files:

• FGRungeKutta.h
• FGRungeKutta.cpp