diff --git a/src/backend/nsl/nsl_corr.c b/src/backend/nsl/nsl_corr.c index 02fb3c673..3938f5e00 100644 --- a/src/backend/nsl/nsl_corr.c +++ b/src/backend/nsl/nsl_corr.c @@ -1,205 +1,208 @@ /*************************************************************************** File : nsl_corr.c Project : LabPlot Description : NSL discrete correlation functions -------------------------------------------------------------------- Copyright : (C) 2018 by Stefan Gerlach (stefan.gerlach@uni.kn) ***************************************************************************/ /*************************************************************************** * * * This program is free software; you can redistribute it and/or modify * * it under the terms of the GNU General Public License as published by * * the Free Software Foundation; either version 2 of the License, or * * (at your option) any later version. * * * * This program is distributed in the hope that it will be useful, * * but WITHOUT ANY WARRANTY; without even the implied warranty of * * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * * GNU General Public License for more details. * * * * You should have received a copy of the GNU General Public License * * along with this program; if not, write to the Free Software * * Foundation, Inc., 51 Franklin Street, Fifth Floor, * * Boston, MA 02110-1301 USA * * * ***************************************************************************/ #include "nsl_corr.h" #include "nsl_common.h" #include #include #ifdef HAVE_FFTW3 #include #endif const char* nsl_corr_type_name[] = {i18n("linear (zero-padded)"), i18n("circular")}; const char* nsl_corr_norm_name[] = {i18n("none"), i18n("biased"), i18n("unbiased"), i18n("coeff")}; int nsl_corr_correlation(double s[], size_t n, double r[], size_t m, nsl_corr_type_type type, nsl_corr_norm_type normalize, double out[]) { return nsl_corr_fft_type(s, n, r, m, type, normalize, out); } int nsl_corr_fft_type(double s[], size_t n, double r[], size_t m, nsl_corr_type_type type, nsl_corr_norm_type normalize, double out[]) { size_t i, size, N = GSL_MAX(n, m), maxlag = N - 1; if (type == nsl_corr_type_linear) size = maxlag + N; else // circular size = N; size_t oldsize = size; #ifdef HAVE_FFTW3 // already zero-pad here for FFT method and FFTW r2c size = 2*(size/2+1); #endif // zero-padded arrays double *stmp = (double*)malloc(size*sizeof(double)); if (stmp == NULL) { printf("nsl_corr_fft_type(): ERROR allocating memory for 'stmp'!\n"); return -1; } double *rtmp = (double*)malloc(size*sizeof(double)); if (rtmp == NULL) { free(stmp); printf("nsl_corr_fft_type(): ERROR allocating memory for 'rtmp'!\n"); return -1; } if (type == nsl_corr_type_linear) { for (i = 0; i < maxlag; i++) stmp[i] = 0.; for (i = 0; i < n; i++) stmp[i+maxlag] = s[i]; for (i = n+maxlag; i < size; i++) stmp[i] = 0; for (i = 0; i < m; i++) rtmp[i] = r[i]; for (i = m; i < size; i++) rtmp[i] = 0; } else { // circular for (i = 0; i < n; i++) stmp[i] = s[i]; for (i = n; i < N; i++) stmp[i] = 0.; for (i = 0; i < m; i++) rtmp[i] = r[i]; for (i = m; i < N; i++) rtmp[i] = 0.; } int status; #ifdef HAVE_FFTW3 // already wraps output status = nsl_corr_fft_FFTW(stmp, rtmp, oldsize, out); #else // GSL status = nsl_corr_fft_GSL(stmp, rtmp, size, out); #endif free(stmp); free(rtmp); /* normalization */ switch (normalize) { case nsl_corr_norm_none: break; case nsl_corr_norm_biased: for (i = 0; i < oldsize; i++) out[i] = out[i]/N; break; case nsl_corr_norm_unbiased: for (i = 0; i < oldsize; i++) { size_t norm = i < oldsize/2 ? i+1 : oldsize - i; out[i] = out[i]/norm; } break; case nsl_corr_norm_coeff: { double snorm = cblas_dnrm2((int)n, s, 1); double rnorm = cblas_dnrm2((int)m, r, 1); for (i = 0; i < oldsize; i++) out[i] = out[i]/snorm/rnorm; break; } } // reverse array for circular type if (type == nsl_corr_type_circular) { for (i = 0; i < N/2; i++) { double tmp = out[i]; out[i] = out[N - i - 1]; out[N -i - 1] = tmp; } } return status; } #ifdef HAVE_FFTW3 int nsl_corr_fft_FFTW(double s[], double r[], size_t n, double out[]) { if (n <= 0) return -1; const size_t size = 2*(n/2+1); + if (size <= 0) + return -1; + double* in = (double*)malloc(size*sizeof(double)); fftw_plan rpf = fftw_plan_dft_r2c_1d(n, in, (fftw_complex*)in, FFTW_ESTIMATE); fftw_execute_dft_r2c(rpf, s, (fftw_complex*)s); fftw_execute_dft_r2c(rpf, r, (fftw_complex*)r); fftw_destroy_plan(rpf); size_t i; // multiply for (i = 0; i < size; i += 2) { double re = s[i]*r[i] + s[i+1]*r[i+1]; double im = s[i+1]*r[i] - s[i]*r[i+1]; s[i] = re; s[i+1] = im; } // back transform double* o = (double*)malloc(size*sizeof(double)); fftw_plan rpb = fftw_plan_dft_c2r_1d(n, (fftw_complex*)o, o, FFTW_ESTIMATE); fftw_execute_dft_c2r(rpb, (fftw_complex*)s, s); fftw_destroy_plan(rpb); for (i = 0; i < n; i++) out[i] = s[i]/n; free(in); free(o); return 0; } #endif int nsl_corr_fft_GSL(double s[], double r[], size_t n, double out[]) { gsl_fft_real_workspace *work = gsl_fft_real_workspace_alloc(n); gsl_fft_real_wavetable *real = gsl_fft_real_wavetable_alloc(n); /* FFT s and r */ gsl_fft_real_transform(s, 1, n, real, work); gsl_fft_real_transform(r, 1, n, real, work); gsl_fft_real_wavetable_free(real); size_t i; /* calculate halfcomplex product */ out[0] = s[0]*r[0]; for (i = 1; i < n; i++) { if (i%2) { /* Re */ out[i] = s[i]*r[i]; if (i < n-1) /* when n is even last value is real */ out[i] += s[i+1]*r[i+1]; } else /* Im */ out[i] = s[i]*r[i-1] - s[i-1]*r[i]; } /* back transform */ gsl_fft_halfcomplex_wavetable *hc = gsl_fft_halfcomplex_wavetable_alloc(n); gsl_fft_halfcomplex_inverse(out, 1, n, hc, work); gsl_fft_halfcomplex_wavetable_free(hc); gsl_fft_real_workspace_free(work); return 0; }