23char cftcossins_C[] =
"$Header: /cvsroot/Lorene/C++/Source/Non_class_members/Coef/FFTW3/cftcossins.C,v 1.3 2014/10/13 08:53:19 j_novak Exp $" ;
118fftw_plan prepare_fft(
int, Tbl*&) ;
119double* cheb_ini(
const int) ;
122void cftcossins(
const int* deg,
const int* dimf,
double* ff,
const int* dimc,
141 cout <<
"cftcossins: nt > n2f : nt = " << nt <<
" , n2f = "
147 cout <<
"cftcossins: nt > n2c : nt = " << nt <<
" , n2c = "
153 cout <<
"cftcossins: n1f > n1c : n1f = " << n1f <<
" , n1c = "
159 cout <<
"cftcossins: n3f > n3c : n3f = " << n3f <<
" , n3c = "
171 fftw_plan p = prepare_fft(nm1, pg) ;
175 double* sinp = cheb_ini(nt);
180 int n2n3f = n2f * n3f ;
181 int n2n3c = n2c * n3c ;
196 for (k=0; k<n3f; k++) {
198 int i0 = n2n3f * j + k ;
199 double* ff0 = ff + i0 ;
202 double* cf0 = cf + i0 ;
207 for ( i = 1; i < nm1s2 ; i++ ) {
210 int ixsym = n3f * isym ;
212 double fp = 0.5 * ( ff0[ix] + ff0[ixsym] ) * sinp[i] ;
214 double fms = 0.5 * ( ff0[ix] - ff0[ixsym] ) ;
215 g.set(i) = fp + fms ;
216 g.set(isym) = fp - fms ;
219 g.set(0) = 0.5 * ( ff0[0] + ff0[ n3f*nm1 ] );
220 g.set(nm1s2) = ff0[ n3f*nm1s2 ];
233 double fac = -2. / double(nm1) ;
235 for (i=2; i<nm1; i += 2 ) cf0[n3c*i] = fac * g(nm1 - i/2) ;
245 cf0[n3c] = -fac * g(0);
247 for ( i = 3; i < nt; i += 2 ) {
248 cf0[n3c*i] = cf0[n3c*(i-2)] + fac * g(i/2) ;
263 for (k=0; k<n3f; k++) {
265 int i0 = n2n3f * j + k ;
266 double* ff0 = ff + i0 ;
269 double* cf0 = cf + i0 ;
273 for ( i = 1; i < nm1s2 ; i++ ) {
276 int ixsym = n3f * isym ;
278 double fp = 0.5 * ( ff0[ix] + ff0[ixsym] ) * sinp[i] ;
280 double fms = 0.5 * ( ff0[ix] - ff0[ixsym] ) ;
281 g.set(i) = fp + fms ;
282 g.set(isym) = fp - fms ;
285 g.set(0) = 0.5 * ( ff0[0] + ff0[ n3f*nm1 ] );
286 g.set(nm1s2) = ff0[ n3f*nm1s2 ];
299 double fac = -2. / double(nm1) ;
301 for (i=2; i<nm1; i += 2 ) cf0[n3c*i] = fac * g(nm1 - i/2) ;
311 cf0[n3c] = -fac * g(0);
313 for ( i = 3; i < nt; i += 2 ) {
314 cf0[n3c*i] = cf0[n3c*(i-2)] + fac * g(i/2) ;
345 for (k=0; k<n3f; k++) {
347 int i0 = n2n3f * j + k ;
348 double* ff0 = ff + i0 ;
351 double* cf0 = cf + i0 ;
355 double fmoins0 = 0.5 * ( ff0[0] - ff0[ n3f*nm1 ] );
359 for ( i = 1; i < nm1s2 ; i++ ) {
362 int ixsym = n3f * isym ;
364 double fp = 0.5 * ( ff0[ix] + ff0[ixsym] ) ;
366 double fms = 0.5 * ( ff0[ix] - ff0[ixsym] ) * sinp[i] ;
367 g.set(i) = fp + fms ;
368 g.set(isym) = fp - fms ;
371 g.set(0) = 0.5 * ( ff0[0] + ff0[ n3f*nm1 ] );
372 g.set(nm1s2) = ff0[ n3f*nm1s2 ];
385 double fac = 2./double(nm1) ;
386 cf0[0] = g(0) / double(nm1) ;
387 for (i=2; i<nm1; i += 2 ) cf0[n3c*i] = fac*g(i/2) ;
388 cf0[n3c*nm1] = g(nm1s2) / double(nm1) ;
399 for ( i = 3; i < nt; i += 2 ) {
400 cf0[n3c*i] = cf0[n3c*(i-2)] + fac * g(nm1 - i/2) ;
405 double c1 = ( fmoins0 - som ) / nm1s2 ;
409 for ( i = 3; i < nt; i += 2 ) cf0[n3c*i] += c1 ;
420 if ( (j != 1) && (j != n1f-1 ) ) {
424 for (k=0; k<n3f; k++) {
426 int i0 = n2n3f * j + k ;
427 double* ff0 = ff + i0 ;
430 double* cf0 = cf + i0 ;
434 double fmoins0 = 0.5 * ( ff0[0] - ff0[ n3f*nm1 ] );
438 for ( i = 1; i < nm1s2 ; i++ ) {
441 int ixsym = n3f * isym ;
443 double fp = 0.5 * ( ff0[ix] + ff0[ixsym] ) ;
445 double fms = 0.5 * ( ff0[ix] - ff0[ixsym] ) * sinp[i] ;
446 g.set(i) = fp + fms ;
447 g.set(isym) = fp - fms ;
450 g.set(0) = 0.5 * ( ff0[0] + ff0[ n3f*nm1 ] );
451 g.set(nm1s2) = ff0[ n3f*nm1s2 ];
464 double fac = 2./double(nm1) ;
465 cf0[0] = g(0) / double(nm1) ;
466 for (i=2; i<nm1; i += 2 ) cf0[n3c*i] = fac*g(i/2) ;
467 cf0[n3c*nm1] = g(nm1s2) / double(nm1) ;
478 for ( i = 3; i < nt; i += 2 ) {
479 cf0[n3c*i] = cf0[n3c*(i-2)] + fac * g(nm1 - i/2) ;
484 double c1 = ( fmoins0 - som ) / nm1s2 ;
488 for ( i = 3; i < nt; i += 2 ) cf0[n3c*i] += c1 ;