#define NRANSI#include "nrutil.h"void wtn(float a[], unsigned long nn[], int ndim, int isign,	void (*wtstep)(float [], unsigned long, int)){	unsigned long i1,i2,i3,k,n,nnew,nprev=1,nt,ntot=1;	int idim;	float *wksp;	for (idim=1;idim<=ndim;idim++) ntot *= nn[idim];	wksp=vector(1,ntot);	for (idim=1;idim<=ndim;idim++) {		n=nn[idim];		nnew=n*nprev;		if (n > 4) {			for (i2=0;i2<ntot;i2+=nnew) {				for (i1=1;i1<=nprev;i1++) {					for (i3=i1+i2,k=1;k<=n;k++,i3+=nprev) wksp[k]=a[i3];					if (isign >= 0) {						for(nt=n;nt>=4;nt >>= 1)							(*wtstep)(wksp,nt,isign);					} else {						for(nt=4;nt<=n;nt <<= 1)							(*wtstep)(wksp,nt,isign);					}					for (i3=i1+i2,k=1;k<=n;k++,i3+=nprev) a[i3]=wksp[k];				}			}		}		nprev=nnew;	}	free_vector(wksp,1,ntot);}#undef NRANSI