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48 #include "gromacs/math/gmxcomplex.h"
49 #include "gromacs/utility/fatalerror.h"
50 #include "gromacs/utility/real.h"
52 /* This file contains common fft utility functions, but not
53 * the actual transform implementations. Check the
54 * files like fft_fftw3.c or fft_mkl.c for that.
57 #if !GMX_FFT_FFTW3 && !GMX_FFT_ARMPL_FFTW3
66 typedef struct gmx_many_fft* gmx_many_fft_t;
68 int gmx_fft_init_many_1d(gmx_fft_t* pfft, int nx, int howmany, gmx_fft_flag flags)
73 gmx_fatal(FARGS, "Invalid opaque FFT datatype pointer.");
78 if ((fft = static_cast<gmx_many_fft_t>(malloc(sizeof(struct gmx_many_fft)))) == nullptr)
83 gmx_fft_init_1d(&fft->fft, nx, flags);
84 fft->howmany = howmany;
87 *pfft = reinterpret_cast<gmx_fft_t>(fft);
91 int gmx_fft_init_many_1d_real(gmx_fft_t* pfft, int nx, int howmany, gmx_fft_flag flags)
96 gmx_fatal(FARGS, "Invalid opaque FFT datatype pointer.");
101 if ((fft = static_cast<gmx_many_fft_t>(malloc(sizeof(struct gmx_many_fft)))) == nullptr)
106 gmx_fft_init_1d_real(&fft->fft, nx, flags);
107 fft->howmany = howmany;
108 fft->dist = 2 * (nx / 2 + 1);
110 *pfft = reinterpret_cast<gmx_fft_t>(fft);
114 int gmx_fft_many_1d(gmx_fft_t fft, enum gmx_fft_direction dir, void* in_data, void* out_data)
116 gmx_many_fft_t mfft = reinterpret_cast<gmx_many_fft_t>(fft);
118 for (i = 0; i < mfft->howmany; i++)
120 ret = gmx_fft_1d(mfft->fft, dir, in_data, out_data);
125 in_data = static_cast<real*>(in_data) + mfft->dist;
126 out_data = static_cast<real*>(out_data) + mfft->dist;
131 int gmx_fft_many_1d_real(gmx_fft_t fft, enum gmx_fft_direction dir, void* in_data, void* out_data)
133 gmx_many_fft_t mfft = reinterpret_cast<gmx_many_fft_t>(fft);
135 for (i = 0; i < mfft->howmany; i++)
137 ret = gmx_fft_1d_real(mfft->fft, dir, in_data, out_data);
142 in_data = static_cast<real*>(in_data) + mfft->dist;
143 out_data = static_cast<real*>(out_data) + mfft->dist;
149 void gmx_many_fft_destroy(gmx_fft_t fft)
151 gmx_many_fft_t mfft = reinterpret_cast<gmx_many_fft_t>(fft);
154 if (mfft->fft != nullptr)
156 gmx_fft_destroy(mfft->fft);
162 #endif // not GMX_FFT_FFTW3
164 int gmx_fft_transpose_2d(t_complex* in_data, t_complex* out_data, int nx, int ny)
166 int i, j, k, im, n, ncount;
168 int i1, i1c, i2, i2c, kmi, max;
170 t_complex tmp1, tmp2, tmp3;
173 /* Use 500 bytes on stack to indicate moves.
174 * This is just for optimization, it does not limit any dimensions.
179 if (nx < 2 || ny < 2)
181 if (in_data != out_data)
183 memcpy(out_data, in_data, sizeof(t_complex) * nx * ny);
188 /* Out-of-place transposes are easy */
189 if (in_data != out_data)
191 for (i = 0; i < nx; i++)
193 for (j = 0; j < ny; j++)
195 out_data[j * nx + i].re = in_data[i * ny + j].re;
196 out_data[j * nx + i].im = in_data[i * ny + j].im;
202 /* In-place transform. in_data=out_data=data */
207 /* trivial case, just swap elements */
208 for (i = 0; i < nx; i++)
210 for (j = i + 1; j < nx; j++)
212 tmp1.re = data[i * nx + j].re;
213 tmp1.im = data[i * nx + j].im;
214 data[i * nx + j].re = data[j * nx + i].re;
215 data[i * nx + j].im = data[j * nx + i].im;
216 data[j * nx + i].re = tmp1.re;
217 data[j * nx + i].im = tmp1.im;
223 for (i = 0; i < nmove; i++)
230 if (nx > 2 && ny > 2)
253 tmp1.re = data[i1].re;
254 tmp1.im = data[i1].im;
256 tmp2.re = data[i1c].re;
257 tmp2.im = data[i1c].im;
262 i2 = ny * i1 - k * (i1 / nx);
289 data[i1].re = data[i2].re;
290 data[i1].im = data[i2].im;
291 data[i1c].re = data[i2c].re;
292 data[i1c].im = data[i2c].im;
298 data[i1].re = tmp1.re;
299 data[i1].im = tmp1.im;
300 data[i1c].re = tmp2.re;
301 data[i1c].im = tmp2.im;
324 while (i2 > i && i2 < max)
327 i2 = ny * i1 - k * (i1 / nx);