23char cftcosi_C[] =
"$Header: /cvsroot/Lorene/C++/Source/Non_class_members/Coef/FFTW3/cftcosi.C,v 1.3 2014/10/13 08:53:19 j_novak Exp $" ;
131fftw_plan prepare_fft(
int, Tbl*&) ;
132double* cheb_ini(
const int) ;
133double* chebimp_ini(
const int ) ;
136void cftcosi(
const int* deg,
const int* dimf,
double* ff,
const int* dimc,
155 cout <<
"cftcosi: nt > n2f : nt = " << nt <<
" , n2f = "
161 cout <<
"cftcosi: nt > n2c : nt = " << nt <<
" , n2c = "
167 cout <<
"cftcosi: n1f > n1c : n1f = " << n1f <<
" , n1c = "
173 cout <<
"cftcosi: n3f > n3c : n3f = " << n3f <<
" , n3c = "
185 fftw_plan p = prepare_fft(nm1, pg) ;
189 double* sinp = cheb_ini(nt);
192 double* x = chebimp_ini(nt);
197 int n2n3f = n2f * n3f ;
198 int n2n3c = n2c * n3c ;
206 int borne_phi = ( n1f > 1 ) ? n1f-1 : 1 ;
208 for (j=0; j< borne_phi; j++) {
212 for (k=0; k<n3f; k++) {
214 int i0 = n2n3f * j + k ;
215 double* ff0 = ff + i0 ;
218 double* cf0 = cf + i0 ;
224 for (i=0; i<nt-1; i++) cf0[n3c*i] = x[nm1-i] * ff0[n3f*i] ;
233 double fmoins0 = 0.5 * ( cf0[0] - cf0[ n3c*nm1 ] );
237 for ( i = 1; i < nm1s2 ; i++ ) {
243 int ixsym = n3c * isym ;
245 double fp = 0.5 * ( cf0[ix] + cf0[ixsym] ) ;
247 double fms = 0.5 * ( cf0[ix] - cf0[ixsym] ) * sinp[i] ;
248 g.set(i) = fp + fms ;
249 g.set(isym) = fp - fms ;
252 g.set(0) = 0.5 * ( cf0[0] + cf0[ n3c*nm1 ] );
253 g.set(nm1s2) = cf0[ n3c*nm1s2 ];
267 double fac = 2./double(nm1) ;
268 cf0[0] = g(0) / double(nm1) ;
269 for (i=2; i<nm1; i += 2 ) cf0[n3c*i] = fac * g(i/2) ;
270 cf0[n3c*nm1] = g(nm1s2) ;
281 for ( i = 3; i < nt; i += 2 ) {
282 cf0[n3c*i] = cf0[n3c*(i-2)] + fac * g(nm1 - i/2) ;
287 double c1 = ( fmoins0 - som ) / nm1s2 ;
291 for ( i = 3; i < nt; i += 2 ) cf0[n3c*i] += c1 ;
298 for (i=1; i<nm1; i++) {
299 cf0[n3c*i] = 2 * cf0[n3c*i] - cf0[n3c*(i-1)] ;