cosmotool/external/sharp/libsharp/sharp_ylmgen_c.c
2012-11-10 09:01:12 -05:00

230 lines
6.5 KiB
C

/*
* This file is part of libsharp.
*
* libsharp 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.
*
* libsharp 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 libsharp; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
* libsharp is being developed at the Max-Planck-Institut fuer Astrophysik
* and financially supported by the Deutsches Zentrum fuer Luft- und Raumfahrt
* (DLR).
*/
/*
* Helper code for efficient calculation of Y_lm(theta,phi=0)
*
* Copyright (C) 2005-2012 Max-Planck-Society
* Author: Martin Reinecke
*/
#include <math.h>
#include <stdlib.h>
#include "sharp_ylmgen_c.h"
#include "c_utils.h"
static inline void normalize (double *val, int *scale, double xfmax)
{
while (fabs(*val)>xfmax) { *val*=sharp_fsmall; ++*scale; }
if (*val!=0.)
while (fabs(*val)<xfmax*sharp_fsmall) { *val*=sharp_fbig; --*scale; }
}
void sharp_Ylmgen_init (sharp_Ylmgen_C *gen, int l_max, int m_max, int spin)
{
const double inv_sqrt4pi = 0.2820947917738781434740397257803862929220;
gen->lmax = l_max;
gen->mmax = m_max;
UTIL_ASSERT(spin>=0,"incorrect spin");
gen->s = spin;
UTIL_ASSERT((sharp_minscale<=0)&&(sharp_maxscale>0),
"bad value for min/maxscale");
gen->cf=RALLOC(double,sharp_maxscale-sharp_minscale+1);
gen->cf[-sharp_minscale]=1.;
for (int m=-sharp_minscale-1; m>=0; --m)
gen->cf[m]=gen->cf[m+1]*sharp_fsmall;
for (int m=-sharp_minscale+1; m<(sharp_maxscale-sharp_minscale+1); ++m)
gen->cf[m]=gen->cf[m-1]*sharp_fbig;
gen->m = -1;
if (spin==0)
{
gen->rf = RALLOC(sharp_ylmgen_dbl2,gen->lmax+1);
gen->mfac = RALLOC(double,gen->mmax+1);
gen->mfac[0] = inv_sqrt4pi;
for (int m=1; m<=gen->mmax; ++m)
gen->mfac[m] = gen->mfac[m-1]*sqrt((2*m+1.)/(2*m));
gen->root = RALLOC(double,2*gen->lmax+5);
gen->iroot = RALLOC(double,2*gen->lmax+5);
for (int m=0; m<2*gen->lmax+5; ++m)
{
gen->root[m] = sqrt(m);
gen->iroot[m] = (m==0) ? 0. : 1./gen->root[m];
}
}
else
{
gen->m=gen->mlo=gen->mhi=-1234567890;
ALLOC(gen->fx,sharp_ylmgen_dbl3,gen->lmax+2);
for (int m=0; m<gen->lmax+2; ++m)
gen->fx[m].f[0]=gen->fx[m].f[1]=gen->fx[m].f[2]=0.;
ALLOC(gen->inv,double,gen->lmax+1);
gen->inv[0]=0;
for (int m=1; m<gen->lmax+1; ++m) gen->inv[m]=1./m;
ALLOC(gen->flm1,double,2*gen->lmax+1);
ALLOC(gen->flm2,double,2*gen->lmax+1);
for (int m=0; m<2*gen->lmax+1; ++m)
{
gen->flm1[m] = sqrt(1./(m+1.));
gen->flm2[m] = sqrt(m/(m+1.));
}
ALLOC(gen->prefac,double,gen->mmax+1);
ALLOC(gen->fscale,int,gen->mmax+1);
double *fac = RALLOC(double,2*gen->lmax+1);
int *facscale = RALLOC(int,2*gen->lmax+1);
fac[0]=1; facscale[0]=0;
for (int m=1; m<2*gen->lmax+1; ++m)
{
fac[m]=fac[m-1]*sqrt(m);
facscale[m]=facscale[m-1];
normalize(&fac[m],&facscale[m],sharp_fbighalf);
}
for (int m=0; m<=gen->mmax; ++m)
{
int mlo=gen->s, mhi=m;
if (mhi<mlo) SWAP(mhi,mlo,int);
double tfac=fac[2*mhi]/fac[mhi+mlo];
int tscale=facscale[2*mhi]-facscale[mhi+mlo];
normalize(&tfac,&tscale,sharp_fbighalf);
tfac/=fac[mhi-mlo];
tscale-=facscale[mhi-mlo];
normalize(&tfac,&tscale,sharp_fbighalf);
gen->prefac[m]=tfac;
gen->fscale[m]=tscale;
}
DEALLOC(fac);
DEALLOC(facscale);
}
}
void sharp_Ylmgen_destroy (sharp_Ylmgen_C *gen)
{
DEALLOC(gen->cf);
if (gen->s==0)
{
DEALLOC(gen->rf);
DEALLOC(gen->mfac);
DEALLOC(gen->root);
DEALLOC(gen->iroot);
}
else
{
DEALLOC(gen->fx);
DEALLOC(gen->prefac);
DEALLOC(gen->fscale);
DEALLOC(gen->flm1);
DEALLOC(gen->flm2);
DEALLOC(gen->inv);
}
}
void sharp_Ylmgen_prepare (sharp_Ylmgen_C *gen, int m)
{
if (m==gen->m) return;
UTIL_ASSERT(m>=0,"incorrect m");
gen->m = m;
if (gen->s==0)
{
gen->rf[m].f[0] = gen->root[2*m+3];
gen->rf[m].f[1] = 0.;
for (int l=m+1; l<=gen->lmax; ++l)
{
double tmp=gen->root[2*l+3]*gen->iroot[l+1+m]*gen->iroot[l+1-m];
gen->rf[l].f[0] = tmp*gen->root[2*l+1];
gen->rf[l].f[1] = tmp*gen->root[l+m]*gen->root[l-m]*gen->iroot[2*l-1];
}
}
else
{
int mlo_=m, mhi_=gen->s;
if (mhi_<mlo_) SWAP(mhi_,mlo_,int);
int ms_similar = ((gen->mhi==mhi_) && (gen->mlo==mlo_));
gen->mlo = mlo_; gen->mhi = mhi_;
if (!ms_similar)
{
for (int l=gen->mhi; l<gen->lmax; ++l)
{
double t = gen->flm1[l+gen->m]*gen->flm1[l-gen->m]
*gen->flm1[l+gen->s]*gen->flm1[l-gen->s];
double lt = 2*l+1;
double l1 = l+1;
gen->fx[l+1].f[0]=l1*lt*t;
gen->fx[l+1].f[1]=gen->m*gen->s*gen->inv[l]*gen->inv[l+1];
t = gen->flm2[l+gen->m]*gen->flm2[l-gen->m]
*gen->flm2[l+gen->s]*gen->flm2[l-gen->s];
gen->fx[l+1].f[2]=t*l1*gen->inv[l];
}
}
gen->preMinus_p = gen->preMinus_m = 0;
if (gen->mhi==gen->m)
{
gen->cosPow = gen->mhi+gen->s; gen->sinPow = gen->mhi-gen->s;
gen->preMinus_p = gen->preMinus_m = ((gen->mhi-gen->s)&1);
}
else
{
gen->cosPow = gen->mhi+gen->m; gen->sinPow = gen->mhi-gen->m;
gen->preMinus_m = ((gen->mhi+gen->m)&1);
}
}
}
double *sharp_Ylmgen_get_norm (int lmax, int spin)
{
const double pi = 3.141592653589793238462643383279502884197;
double *res=RALLOC(double,lmax+1);
/* sign convention for H=1 (LensPix paper) */
#if 1
double spinsign = (spin>0) ? -1.0 : 1.0;
#else
double spinsign = 1.0;
#endif
if (spin==0)
{
for (int l=0; l<=lmax; ++l)
res[l]=1.;
return res;
}
spinsign = (spin&1) ? -spinsign : spinsign;
for (int l=0; l<=lmax; ++l)
res[l] = (l<spin) ? 0. : spinsign*0.5*sqrt((2*l+1)/(4*pi));
return res;
}
double *sharp_Ylmgen_get_d1norm (int lmax)
{
const double pi = 3.141592653589793238462643383279502884197;
double *res=RALLOC(double,lmax+1);
for (int l=0; l<=lmax; ++l)
res[l] = (l<1) ? 0. : 0.5*sqrt(l*(l+1.)*(2*l+1.)/(4*pi));
return res;
}