com_fft.c, use FFTW3 for com_fft() and com_psd()
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dwarning
rlar
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a90f916883
commit
8ed75d166d
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@ -7,8 +7,6 @@ Author: 2008 Holger Vogt
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* Code to do fast fourier transform on data.
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*/
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#define GREEN /* select fast Green's fft */
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#include "ngspice/ngspice.h"
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#include "ngspice/ftedefs.h"
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#include "ngspice/dvec.h"
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@ -20,6 +18,10 @@ Author: 2008 Holger Vogt
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#include "../misc/misc_time.h"
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#include "ngspice/fftext.h"
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#ifdef HAVE_LIBFFTW3
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#include "fftw3.h"
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#endif
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void
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com_fft(wordlist *wl)
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@ -33,13 +35,16 @@ com_fft(wordlist *wl)
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struct pnode *pn, *names = NULL;
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char window[BSIZE_SP];
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double maxt;
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double *in = NULL;
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#ifdef GREEN
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int M;
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#ifdef HAVE_LIBFFTW3
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fftw_complex *out = NULL;
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fftw_plan plan_forward = NULL;
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#else
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int N, M;
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#endif
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double *reald = NULL, *imagd = NULL;
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int N, order;
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int order;
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double scale;
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if (!plot_cur || !plot_cur->pl_scale) {
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@ -56,7 +61,9 @@ com_fft(wordlist *wl)
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time = (plot_cur->pl_scale)->v_realdata;
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span = time[tlen-1] - time[0];
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#ifdef GREEN
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#ifdef HAVE_LIBFFTW3
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fpts = tlen/2 + 1;
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#else
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/* size of fft input vector is power of two and larger or equal than spice vector */
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N = 1;
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M = 0;
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@ -64,14 +71,8 @@ com_fft(wordlist *wl)
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N <<= 1;
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M++;
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}
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#else
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/* size of input vector is power of two and larger than spice vector */
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N = 1;
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while (N < tlen)
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N *= 2;
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#endif
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/* output vector has length of N/2 */
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fpts = N/2;
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#endif
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win = TMALLOC(double, tlen);
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maxt = time[tlen-1];
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@ -138,7 +139,11 @@ com_fft(wordlist *wl)
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vec_new(f);
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for (i = 0; i<fpts; i++)
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#ifdef HAVE_LIBFFTW3
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freq[i] = i*1.0/span;
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#else
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freq[i] = i*1.0/span*tlen/N;
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#endif
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tdvec = TMALLOC(double *, ngood);
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fdvec = TMALLOC(ngcomplex_t *, ngood);
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@ -156,48 +161,69 @@ com_fft(wordlist *wl)
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vec = vec->v_link2;
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}
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printf("FFT: Time span: %g s, input length: %d, zero padding: %d\n", span, N, N-tlen);
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printf("FFT: Freq. resolution: %g Hz, output length: %d\n", 1.0/span*tlen/N, fpts);
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#ifdef HAVE_LIBFFTW3
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printf("FFT: Time span: %g s, input length: %d\n", span, tlen);
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printf("FFT: Frequency resolution: %g Hz, output length: %d\n", 1.0/span, fpts);
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reald = TMALLOC(double, N);
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imagd = TMALLOC(double, N);
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for (i = 0; i<ngood; i++) {
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in = fftw_malloc(sizeof(double) * (unsigned int) tlen);
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out = fftw_malloc(sizeof(fftw_complex) * (unsigned int) fpts);
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for (j = 0; j < tlen; j++)
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in[j] = tdvec[i][j]*win[j];
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plan_forward = fftw_plan_dft_r2c_1d(tlen, in, out, FFTW_ESTIMATE);
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fftw_execute(plan_forward);
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scale = (double) tlen;
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for (j = 0; j < fpts; j++) {
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fdvec[i][j].cx_real = out[j][0]/scale;
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fdvec[i][j].cx_imag = out[j][1]/scale;
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}
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fftw_free(in);
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fftw_free(out);
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#else /* Green's FFT */
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printf("FFT: Time span: %g s, input length: %d, zero padding: %d\n", span, tlen, N-tlen);
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printf("FFT: Frequency resolution: %g Hz, output length: %d\n", 1.0/span, fpts);
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for (i = 0; i<ngood; i++) {
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in = TMALLOC(double, N);
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for (j = 0; j < tlen; j++) {
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reald[j] = tdvec[i][j]*win[j];
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imagd[j] = 0.0;
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in[j] = tdvec[i][j]*win[j];
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}
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for (j = tlen; j < N; j++) {
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reald[j] = 0.0;
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imagd[j] = 0.0;
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in[j] = 0.0;
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}
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#ifdef GREEN
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// Green's FFT
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fftInit(M);
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rffts(reald, M, 1);
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rffts(in, M, 1);
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fftFree();
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scale = (double) N;
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/* Re(x[0]), Re(x[N/2]), Re(x[1]), Im(x[1]), Re(x[2]), Im(x[2]), ... Re(x[N/2-1]), Im(x[N/2-1]). */
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for (j = 0; j < fpts; j++) {
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fdvec[i][j].cx_real = reald[2*j]/scale;
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fdvec[i][j].cx_imag = reald[2*j+1]/scale;
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fdvec[i][j].cx_real = in[2*j]/scale;
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fdvec[i][j].cx_imag = in[2*j+1]/scale;
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}
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fdvec[i][0].cx_imag = 0;
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#else
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fftext(reald, imagd, N, tlen, 1 /* forward */);
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scale = 0.66;
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for (j = 0; j < fpts; j++) {
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fdvec[i][j].cx_real = reald[j]/scale;
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fdvec[i][j].cx_imag = imagd[j]/scale;
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}
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tfree(in);
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#endif
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}
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done:
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tfree(reald);
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tfree(imagd);
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#ifdef HAVE_LIBFFTW3
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fftw_destroy_plan(plan_forward);
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#endif
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tfree(tdvec);
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tfree(fdvec);
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tfree(win);
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@ -213,15 +239,22 @@ com_psd(wordlist *wl)
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double **tdvec = NULL;
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double *freq, *win = NULL, *time, *ave;
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double span, noipower;
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int M;
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int N, ngood, fpts, i, j, tlen, jj, smooth, hsmooth;
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int ngood, fpts, i, j, jj, tlen, smooth, hsmooth;
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char *s;
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struct dvec *f, *vlist, *lv = NULL, *vec;
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struct pnode *pn, *names = NULL;
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char window[BSIZE_SP];
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double maxt;
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double maxt, intres;
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double *reald = NULL, *imagd = NULL;
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#ifdef HAVE_LIBFFTW3
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double *in = NULL;
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fftw_complex *out = NULL;
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fftw_plan plan_forward = NULL;
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#else
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int N, M;
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#endif
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double *reald = NULL;
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double scaling, sum;
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int order;
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@ -251,6 +284,9 @@ com_psd(wordlist *wl)
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wl = wl->wl_next;
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#ifdef HAVE_LIBFFTW3
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fpts = tlen/2 + 1;
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#else
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/* size of fft input vector is power of two and larger or equal than spice vector */
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N = 1;
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M = 0;
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@ -258,9 +294,8 @@ com_psd(wordlist *wl)
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N <<= 1;
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M++;
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}
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// output vector has length of N/2
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fpts = N/2;
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#endif
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win = TMALLOC(double, tlen);
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maxt = time[tlen-1];
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@ -326,8 +361,13 @@ com_psd(wordlist *wl)
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f->v_realdata = freq;
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vec_new(f);
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#ifdef HAVE_LIBFFTW3
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for (i = 0; i <= fpts; i++)
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freq[i] = i*1./span;
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#else
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for (i = 0; i <= fpts; i++)
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freq[i] = i*1./span*tlen/N;
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#endif
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tdvec = TMALLOC(double*, ngood);
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fdvec = TMALLOC(ngcomplex_t*, ngood);
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@ -345,26 +385,55 @@ com_psd(wordlist *wl)
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vec = vec->v_link2;
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}
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printf("PSD: Time span: %g s, input length: %d, zero padding: %d\n", span, N, N-tlen);
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printf("PSD: Freq. resolution: %g Hz, output length: %d\n", 1.0/span*tlen/N, fpts);
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#ifdef HAVE_LIBFFTW3
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reald = TMALLOC(double, N);
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imagd = TMALLOC(double, N);
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printf("PSD: Time span: %g s, input length: %d\n", span, tlen);
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printf("PSD: Frequency resolution: %g Hz, output length: %d\n", 1.0/span, fpts);
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// scale = 0.66;
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reald = TMALLOC(double, fpts);
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in = fftw_malloc(sizeof(double) * (unsigned int) tlen);
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out = fftw_malloc(sizeof(fftw_complex) * (unsigned int) fpts);
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for (i = 0; i<ngood; i++) {
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double intres;
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for (j = 0; j < tlen; j++)
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in[j] = tdvec[i][j]*win[j];
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plan_forward = fftw_plan_dft_r2c_1d(tlen, in, out, FFTW_ESTIMATE);
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fftw_execute(plan_forward);
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scaling = (double) tlen;
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intres = (double)tlen * (double)tlen;
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noipower = fdvec[i][0].cx_real = out[0][0]*out[0][0]/intres;
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fdvec[i][fpts].cx_real = out[1][0]*out[1][0]/intres;
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noipower += fdvec[i][fpts-1].cx_real;
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for (j = 1; j < fpts; j++) {
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fdvec[i][j].cx_real = 2.* (out[j][0]*out[j][0] + out[j+1][0]*out[j+1][0])/intres;
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fdvec[i][j].cx_imag = 0;
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noipower += fdvec[i][j].cx_real;
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if (!finite(noipower))
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break;
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}
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#else /* Green's FFT */
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printf("PSD: Time span: %g s, input length: %d, zero padding: %d\n", span, N, N-tlen);
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printf("PSD: Frequency resolution: %g Hz, output length: %d\n", 1.0/span, fpts);
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reald = TMALLOC(double, N);
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for (i = 0; i<ngood; i++) {
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for (j = 0; j < tlen; j++) {
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reald[j] = (tdvec[i][j]*win[j]);
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imagd[j] = 0.;
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}
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for (j = tlen; j < N; j++) {
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reald[j] = 0.;
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imagd[j] = 0.;
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}
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// Green's FFT
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fftInit(M);
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rffts(reald, M, 1);
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fftFree();
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@ -385,6 +454,8 @@ com_psd(wordlist *wl)
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break;
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}
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#endif
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printf("Total noise power up to Nyquist frequency %5.3e Hz:\n%e V^2 (or A^2), \nnoise voltage or current %e V (or A)\n",
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freq[fpts], noipower, sqrt(noipower));
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@ -420,12 +491,16 @@ com_psd(wordlist *wl)
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}
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done:
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free(reald);
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free(imagd);
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#ifdef HAVE_LIBFFTW3
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fftw_free(in);
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fftw_free(out);
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fftw_destroy_plan(plan_forward);
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#endif
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tfree(tdvec);
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tfree(fdvec);
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tfree(win);
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free(reald);
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free_pnode(names);
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}
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