71 lines
1.5 KiB
Org Mode
71 lines
1.5 KiB
Org Mode
#+title: Test
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#+begin_src C :includes '(<stdlib.h> <stdio.h> <stdint.h> <math.h>) :libs -lm
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#define SWAP(a,b) tempr=(a);(a)=(b);(b)=tempr
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void dfour1(double data[], unsigned long nn, int isign)
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{
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unsigned long n,mmax,m,j,istep,i;
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double wtemp,wr,wpr,wpi,wi,theta;
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double tempr,tempi;
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n=nn << 1;
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j=1;
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for (i=1;i<n;i+=2) {
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if (j > i) {
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SWAP(data[j],data[i]);
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SWAP(data[j+1],data[i+1]);
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}
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m=n >> 1;
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while (m >= 2 && j > m) {
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j -= m;
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m >>= 1;
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}
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j += m;
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}
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mmax=2;
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while (n > mmax) {
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istep=mmax << 1;
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theta=isign*(6.28318530717959/mmax);
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wtemp=sin(0.5*theta);
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wpr = -2.0*wtemp*wtemp;
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wpi=sin(theta);
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wr=1.0;
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wi=0.0;
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for (m=1;m<mmax;m+=2) {
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for (i=m;i<=n;i+=istep) {
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j=i+mmax;
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tempr=wr*data[j]-wi*data[j+1];
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tempi=wr*data[j+1]+wi*data[j];
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data[j]=data[i]-tempr;
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data[j+1]=data[i+1]-tempi;
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data[i] += tempr;
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data[i+1] += tempi;
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}
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wr=(wtemp=wr)*wpr-wi*wpi+wr;
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wi=wi*wpr+wtemp*wpi+wi;
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}
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mmax=istep;
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}
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}
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#undef SWAP
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double d[] = {1.5, 2.5, -0.8, 1.2, 2.2, -1.0, -0.5, 0.4, 2.4, 3.1, 0.1, 3.8, 5.0, -0.1, 3.2, 2.1};
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//double d[] = {1.0, 1.0, 1.0, 1.0, 0.0, 0.0, 0.0, 0.0};
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//double d[] = {0.0, 0.0, 1.0, 0.0, 2.0, 0.0, 3.0, 0.0};
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dfour1(d-1, 8, 1);
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for (int i = 0; i <16; ++i) {
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printf("%f, ", d[i]);
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}
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printf("\n");
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#+end_src
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#+RESULTS:
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| 13.1 | 12.0 | 5.020458 | -7.289087 | -5.8 | 3.3 | -0.73934 | -0.416295 | 9.1 | -3.0 | -5.020458 | 0.489087 | -0.8 | 10.1 | -2.86066 | 4.816295 | |
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