#define NRANSI#include "nrutil.h"float **y,*xx;void rkdumb(float vstart[], int nvar, float x1, float x2, int nstep,	void (*derivs)(float, float [], float [])){	void rk4(float y[], float dydx[], int n, float x, float h, float yout[],		void (*derivs)(float, float [], float []));	int i,k;	float x,h;	float *v,*vout,*dv;	v=vector(1,nvar);	vout=vector(1,nvar);	dv=vector(1,nvar);	for (i=1;i<=nvar;i++) {		v[i]=vstart[i];		y[i][1]=v[i];	}	xx[1]=x1;	x=x1;	h=(x2-x1)/nstep;	for (k=1;k<=nstep;k++) {		(*derivs)(x,v,dv);		rk4(v,dv,nvar,x,h,vout,derivs);		if ((float)(x+h) == x) nrerror("Step size too small in routine rkdumb");		x += h;		xx[k+1]=x;		for (i=1;i<=nvar;i++) {			v[i]=vout[i];			y[i][k+1]=v[i];		}	}	free_vector(dv,1,nvar);	free_vector(vout,1,nvar);	free_vector(v,1,nvar);}#undef NRANSI