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