#include <math.h>void rlft3(float ***data, float **speq, unsigned long nn1, unsigned long nn2,	unsigned long nn3, int isign){	void fourn(float data[], unsigned long nn[], int ndim, int isign);	void nrerror(char error_text[]);	unsigned long i1,i2,i3,j1,j2,j3,nn[4],ii3;	double theta,wi,wpi,wpr,wr,wtemp;	float c1,c2,h1r,h1i,h2r,h2i;	if (1+&data[nn1][nn2][nn3]-&data[1][1][1] != nn1*nn2*nn3)		nrerror("rlft3: problem with dimensions or contiguity of data array\n");	c1=0.5;	c2 = -0.5*isign;	theta=isign*(6.28318530717959/nn3);	wtemp=sin(0.5*theta);	wpr = -2.0*wtemp*wtemp;	wpi=sin(theta);	nn[1]=nn1;	nn[2]=nn2;	nn[3]=nn3 >> 1;	if (isign == 1) {		fourn(&data[1][1][1]-1,nn,3,isign);		for (i1=1;i1<=nn1;i1++)			for (i2=1,j2=0;i2<=nn2;i2++) {				speq[i1][++j2]=data[i1][i2][1];				speq[i1][++j2]=data[i1][i2][2];			}	}	for (i1=1;i1<=nn1;i1++) {		j1=(i1 != 1 ? nn1-i1+2 : 1);		wr=1.0;		wi=0.0;		for (ii3=1,i3=1;i3<=(nn3>>2)+1;i3++,ii3+=2) {			for (i2=1;i2<=nn2;i2++) {				if (i3 == 1) {					j2=(i2 != 1 ? ((nn2-i2)<<1)+3 : 1);					h1r=c1*(data[i1][i2][1]+speq[j1][j2]);					h1i=c1*(data[i1][i2][2]-speq[j1][j2+1]);					h2i=c2*(data[i1][i2][1]-speq[j1][j2]);					h2r= -c2*(data[i1][i2][2]+speq[j1][j2+1]);					data[i1][i2][1]=h1r+h2r;					data[i1][i2][2]=h1i+h2i;					speq[j1][j2]=h1r-h2r;					speq[j1][j2+1]=h2i-h1i;				} else {					j2=(i2 != 1 ? nn2-i2+2 : 1);					j3=nn3+3-(i3<<1);					h1r=c1*(data[i1][i2][ii3]+data[j1][j2][j3]);					h1i=c1*(data[i1][i2][ii3+1]-data[j1][j2][j3+1]);					h2i=c2*(data[i1][i2][ii3]-data[j1][j2][j3]);					h2r= -c2*(data[i1][i2][ii3+1]+data[j1][j2][j3+1]);					data[i1][i2][ii3]=h1r+wr*h2r-wi*h2i;					data[i1][i2][ii3+1]=h1i+wr*h2i+wi*h2r;					data[j1][j2][j3]=h1r-wr*h2r+wi*h2i;					data[j1][j2][j3+1]= -h1i+wr*h2i+wi*h2r;				}			}			wr=(wtemp=wr)*wpr-wi*wpi+wr;			wi=wi*wpr+wtemp*wpi+wi;		}	}	if (isign == -1)		fourn(&data[1][1][1]-1,nn,3,isign);}