23char cfrcheb_C[] =
"$Header: /cvsroot/Lorene/C++/Source/Non_class_members/Coef/FFTW3/cfrcheb.C,v 1.3 2014/10/13 08:53:18 j_novak Exp $" ;
132fftw_plan prepare_fft(
int, Tbl*&) ;
133double* cheb_ini(
const int) ;
137void cfrcheb(
const int* deg,
const int* dimf,
double* ff,
const int* dimc,
157 cout <<
"cfrcheb: nr > n3f : nr = " << nr <<
" , n3f = "
163 cout <<
"cfrcheb: nr > n3c : nr = " << nr <<
" , n3c = "
169 cout <<
"cfrcheb: n1f > n1c : n1f = " << n1f <<
" , n1c = "
175 cout <<
"cfrcheb: n2f > n2c : n2f = " << n2f <<
" , n2c = "
188 fftw_plan p = prepare_fft(nm1, pg) ;
192 double* sinp = cheb_ini(nr);
196 int n2n3f = n2f * n3f ;
197 int n2n3c = n2c * n3c ;
205 int borne_phi = ( n1f > 1 ) ? n1f-1 : 1 ;
207 for (j=0; j< borne_phi; j++) {
211 for (k=0; k<n2f; k++) {
213 int i0 = n2n3f * j + n3f * k ;
214 double* ff0 = ff + i0 ;
216 i0 = n2n3c * j + n3c * k ;
217 double* cf0 = cf + i0 ;
225 double fmoins0 = 0.5 * ( ff0[0] - ff0[nm1] );
229 for ( i = 1; i < nm1s2 ; i++ ) {
233 double fp = 0.5 * ( ff0[i] + ff0[isym] ) ;
235 double fms = 0.5 * ( ff0[i] - ff0[isym] ) * sinp[i] ;
236 g.set(i) = fp + fms ;
237 g.set(isym) = fp - fms ;
240 g.set(0) = 0.5 * ( ff0[0] + ff0[nm1] );
241 g.set(nm1s2) = ff0[nm1s2];
254 double fac = 2./double(nm1) ;
255 cf0[0] = g(0) / double(nm1) ;
256 for (i=2; i<nm1; i += 2) cf0[i] = fac*g(i/2) ;
257 cf0[nm1] = g(nm1s2) / double(nm1) ;
268 for ( i = 3; i < nr; i += 2 ) {
269 cf0[i] = cf0[i-2] + fac * g(nm1-i/2) ;
274 double c1 = - ( fmoins0 + som ) / nm1s2 ;
278 for ( i = 3; i < nr; i += 2 ) cf0[i] += c1 ;