#include <math.h>#define NRANSI#include "nrutil.h"#define ERRTOL 0.05#define TINY 2.5e-13#define BIG 9.0e11#define C1 (3.0/14.0)#define C2 (1.0/3.0)#define C3 (3.0/22.0)#define C4 (3.0/26.0)#define C5 (0.75*C3)#define C6 (1.5*C4)#define C7 (0.5*C2)#define C8 (C3+C3)float rj(float x, float y, float z, float p){	float rc(float x, float y);	float rf(float x, float y, float z);	float a,alamb,alpha,ans,ave,b,beta,delp,delx,dely,delz,ea,eb,ec,		ed,ee,fac,pt,rcx,rho,sqrtx,sqrty,sqrtz,sum,tau,xt,yt,zt;	if (FMIN(FMIN(x,y),z) < 0.0 || FMIN(FMIN(x+y,x+z),FMIN(y+z,fabs(p))) < TINY		|| FMAX(FMAX(x,y),FMAX(z,fabs(p))) > BIG)			nrerror("invalid arguments in rj");	sum=0.0;	fac=1.0;	if (p > 0.0) {		xt=x;		yt=y;		zt=z;		pt=p;	} else {		xt=FMIN(FMIN(x,y),z);		zt=FMAX(FMAX(x,y),z);		yt=x+y+z-xt-zt;		a=1.0/(yt-p);		b=a*(zt-yt)*(yt-xt);		pt=yt+b;		rho=xt*zt/yt;		tau=p*pt/yt;		rcx=rc(rho,tau);	}	do {		sqrtx=sqrt(xt);		sqrty=sqrt(yt);		sqrtz=sqrt(zt);		alamb=sqrtx*(sqrty+sqrtz)+sqrty*sqrtz;		alpha=SQR(pt*(sqrtx+sqrty+sqrtz)+sqrtx*sqrty*sqrtz);		beta=pt*SQR(pt+alamb);		sum += fac*rc(alpha,beta);		fac=0.25*fac;		xt=0.25*(xt+alamb);		yt=0.25*(yt+alamb);		zt=0.25*(zt+alamb);		pt=0.25*(pt+alamb);		ave=0.2*(xt+yt+zt+pt+pt);		delx=(ave-xt)/ave;		dely=(ave-yt)/ave;		delz=(ave-zt)/ave;		delp=(ave-pt)/ave;	} while (FMAX(FMAX(fabs(delx),fabs(dely)),		FMAX(fabs(delz),fabs(delp))) > ERRTOL);	ea=delx*(dely+delz)+dely*delz;	eb=delx*dely*delz;	ec=delp*delp;	ed=ea-3.0*ec;	ee=eb+2.0*delp*(ea-ec);	ans=3.0*sum+fac*(1.0+ed*(-C1+C5*ed-C6*ee)+eb*(C7+delp*(-C8+delp*C4))		+delp*ea*(C2-delp*C3)-C2*delp*ec)/(ave*sqrt(ave));	if (p <= 0.0) ans=a*(b*ans+3.0*(rcx-rf(xt,yt,zt)));	return ans;}#undef ERRTOL#undef TINY#undef BIG#undef C1#undef C2#undef C3#undef C4#undef C5#undef C6#undef C7#undef C8#undef NRANSI