cosmotool/external/sharp/libsharp/sharp_geomhelpers.c

318 lines
9.3 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).
*/
/*! \file sharp_geomhelpers.c
* Spherical transform library
*
* Copyright (C) 2006-2012 Max-Planck-Society<br>
* Copyright (C) 2007-2008 Pavel Holoborodko (for gauss_legendre_tbl)
* \author Martin Reinecke \author Pavel Holoborodko
*/
#include <math.h>
#include "sharp_geomhelpers.h"
#include "sharp_legendre_roots.h"
#include "c_utils.h"
#include "ls_fft.h"
#include <stdio.h>
void sharp_make_subset_healpix_geom_info (int nside, int stride, int nrings,
const int *rings, const double *weight, sharp_geom_info **geom_info)
{
const double pi=3.141592653589793238462643383279502884197;
ptrdiff_t npix=(ptrdiff_t)nside*nside*12;
ptrdiff_t ncap=2*(ptrdiff_t)nside*(nside-1);
double *theta=RALLOC(double,nrings);
double *weight_=RALLOC(double,nrings);
int *nph=RALLOC(int,nrings);
double *phi0=RALLOC(double,nrings);
ptrdiff_t *ofs=RALLOC(ptrdiff_t,nrings);
int *stride_=RALLOC(int,nrings);
ptrdiff_t curofs=0, checkofs; /* checkofs used for assertion introduced when adding rings arg */
for (int m=0; m<nrings; ++m)
{
int ring = (rings==NULL)? (m+1) : rings[m];
ptrdiff_t northring = (ring>2*nside) ? 4*nside-ring : ring;
stride_[m] = stride;
if (northring < nside)
{
theta[m] = 2*asin(northring/(sqrt(6.)*nside));
nph[m] = 4*northring;
phi0[m] = pi/nph[m];
checkofs = 2*northring*(northring-1)*stride;
}
else
{
double fact1 = (8.*nside)/npix;
double costheta = (2*nside-northring)*fact1;
theta[m] = acos(costheta);
nph[m] = 4*nside;
if ((northring-nside) & 1)
phi0[m] = 0;
else
phi0[m] = pi/nph[m];
checkofs = (ncap + (northring-nside)*nph[m])*stride;
ofs[m] = curofs;
}
if (northring != ring) /* southern hemisphere */
{
theta[m] = pi-theta[m];
checkofs = (npix - nph[m])*stride - checkofs;
ofs[m] = curofs;
}
weight_[m]=4.*pi/npix*((weight==NULL) ? 1. : weight[northring-1]);
if (rings==NULL) {
UTIL_ASSERT(curofs==checkofs, "Bug in computing ofs[m]");
}
ofs[m] = curofs;
curofs+=nph[m];
}
sharp_make_geom_info (nrings, nph, ofs, stride_, phi0, theta, weight_,
geom_info);
DEALLOC(theta);
DEALLOC(weight_);
DEALLOC(nph);
DEALLOC(phi0);
DEALLOC(ofs);
DEALLOC(stride_);
}
void sharp_make_weighted_healpix_geom_info (int nside, int stride,
const double *weight, sharp_geom_info **geom_info)
{
sharp_make_subset_healpix_geom_info(nside, stride, 4 * nside - 1, NULL, weight, geom_info);
}
void sharp_make_gauss_geom_info (int nrings, int nphi, double phi0,
int stride_lon, int stride_lat, sharp_geom_info **geom_info)
{
const double pi=3.141592653589793238462643383279502884197;
double *theta=RALLOC(double,nrings);
double *weight=RALLOC(double,nrings);
int *nph=RALLOC(int,nrings);
double *phi0_=RALLOC(double,nrings);
ptrdiff_t *ofs=RALLOC(ptrdiff_t,nrings);
int *stride_=RALLOC(int,nrings);
sharp_legendre_roots(nrings,theta,weight);
for (int m=0; m<nrings; ++m)
{
theta[m] = acos(-theta[m]);
nph[m]=nphi;
phi0_[m]=phi0;
ofs[m]=(ptrdiff_t)m*stride_lat;
stride_[m]=stride_lon;
weight[m]*=2*pi/nphi;
}
sharp_make_geom_info (nrings, nph, ofs, stride_, phi0_, theta, weight,
geom_info);
DEALLOC(theta);
DEALLOC(weight);
DEALLOC(nph);
DEALLOC(phi0_);
DEALLOC(ofs);
DEALLOC(stride_);
}
/* Weights from Waldvogel 2006: BIT Numerical Mathematics 46, p. 195 */
void sharp_make_fejer1_geom_info (int nrings, int ppring, double phi0,
int stride_lon, int stride_lat, sharp_geom_info **geom_info)
{
const double pi=3.141592653589793238462643383279502884197;
double *theta=RALLOC(double,nrings);
double *weight=RALLOC(double,nrings);
int *nph=RALLOC(int,nrings);
double *phi0_=RALLOC(double,nrings);
ptrdiff_t *ofs=RALLOC(ptrdiff_t,nrings);
int *stride_=RALLOC(int,nrings);
weight[0]=2.;
for (int k=1; k<=(nrings-1)/2; ++k)
{
weight[2*k-1]=2./(1.-4.*k*k)*cos((k*pi)/nrings);
weight[2*k ]=2./(1.-4.*k*k)*sin((k*pi)/nrings);
}
if ((nrings&1)==0) weight[nrings-1]=0.;
real_plan plan = make_real_plan(nrings);
real_plan_backward_fftpack(plan,weight);
kill_real_plan(plan);
for (int m=0; m<(nrings+1)/2; ++m)
{
theta[m]=pi*(m+0.5)/nrings;
theta[nrings-1-m]=pi-theta[m];
nph[m]=nph[nrings-1-m]=ppring;
phi0_[m]=phi0_[nrings-1-m]=phi0;
ofs[m]=(ptrdiff_t)m*stride_lat;
ofs[nrings-1-m]=(ptrdiff_t)((nrings-1-m)*stride_lat);
stride_[m]=stride_[nrings-1-m]=stride_lon;
weight[m]=weight[nrings-1-m]=weight[m]*2*pi/(nrings*nph[m]);
}
sharp_make_geom_info (nrings, nph, ofs, stride_, phi0_, theta, weight,
geom_info);
DEALLOC(theta);
DEALLOC(weight);
DEALLOC(nph);
DEALLOC(phi0_);
DEALLOC(ofs);
DEALLOC(stride_);
}
/* Weights from Waldvogel 2006: BIT Numerical Mathematics 46, p. 195 */
void sharp_make_cc_geom_info (int nrings, int ppring, double phi0,
int stride_lon, int stride_lat, sharp_geom_info **geom_info)
{
const double pi=3.141592653589793238462643383279502884197;
double *theta=RALLOC(double,nrings);
double *weight=RALLOC(double,nrings);
int *nph=RALLOC(int,nrings);
double *phi0_=RALLOC(double,nrings);
ptrdiff_t *ofs=RALLOC(ptrdiff_t,nrings);
int *stride_=RALLOC(int,nrings);
int n=nrings-1;
SET_ARRAY(weight,0,nrings,0.);
double dw=-1./(n*n-1.+(n&1));
weight[0]=2.+dw;
for (int k=1; k<=(n/2-1); ++k)
weight[2*k-1]=2./(1.-4.*k*k) + dw;
weight[2*(n/2)-1]=(n-3.)/(2*(n/2)-1) -1. -dw*((2-(n&1))*n-1);
real_plan plan = make_real_plan(n);
real_plan_backward_fftpack(plan,weight);
kill_real_plan(plan);
weight[n]=weight[0];
for (int m=0; m<(nrings+1)/2; ++m)
{
theta[m]=pi*m/(nrings-1.);
if (theta[m]<1e-15) theta[m]=1e-15;
theta[nrings-1-m]=pi-theta[m];
nph[m]=nph[nrings-1-m]=ppring;
phi0_[m]=phi0_[nrings-1-m]=phi0;
ofs[m]=(ptrdiff_t)m*stride_lat;
ofs[nrings-1-m]=(ptrdiff_t)((nrings-1-m)*stride_lat);
stride_[m]=stride_[nrings-1-m]=stride_lon;
weight[m]=weight[nrings-1-m]=weight[m]*2*pi/(n*nph[m]);
}
sharp_make_geom_info (nrings, nph, ofs, stride_, phi0_, theta, weight,
geom_info);
DEALLOC(theta);
DEALLOC(weight);
DEALLOC(nph);
DEALLOC(phi0_);
DEALLOC(ofs);
DEALLOC(stride_);
}
/* Weights from Waldvogel 2006: BIT Numerical Mathematics 46, p. 195 */
void sharp_make_fejer2_geom_info (int nrings, int ppring, double phi0,
int stride_lon, int stride_lat, sharp_geom_info **geom_info)
{
const double pi=3.141592653589793238462643383279502884197;
double *theta=RALLOC(double,nrings);
double *weight=RALLOC(double,nrings+1);
int *nph=RALLOC(int,nrings);
double *phi0_=RALLOC(double,nrings);
ptrdiff_t *ofs=RALLOC(ptrdiff_t,nrings);
int *stride_=RALLOC(int,nrings);
int n=nrings+1;
SET_ARRAY(weight,0,n,0.);
weight[0]=2.;
for (int k=1; k<=(n/2-1); ++k)
weight[2*k-1]=2./(1.-4.*k*k);
weight[2*(n/2)-1]=(n-3.)/(2*(n/2)-1) -1.;
real_plan plan = make_real_plan(n);
real_plan_backward_fftpack(plan,weight);
kill_real_plan(plan);
for (int m=0; m<nrings; ++m)
weight[m]=weight[m+1];
for (int m=0; m<(nrings+1)/2; ++m)
{
theta[m]=pi*(m+1)/(nrings+1.);
theta[nrings-1-m]=pi-theta[m];
nph[m]=nph[nrings-1-m]=ppring;
phi0_[m]=phi0_[nrings-1-m]=phi0;
ofs[m]=(ptrdiff_t)m*stride_lat;
ofs[nrings-1-m]=(ptrdiff_t)((nrings-1-m)*stride_lat);
stride_[m]=stride_[nrings-1-m]=stride_lon;
weight[m]=weight[nrings-1-m]=weight[m]*2*pi/(n*nph[m]);
}
sharp_make_geom_info (nrings, nph, ofs, stride_, phi0_, theta, weight,
geom_info);
DEALLOC(theta);
DEALLOC(weight);
DEALLOC(nph);
DEALLOC(phi0_);
DEALLOC(ofs);
DEALLOC(stride_);
}
void sharp_make_mw_geom_info (int nrings, int ppring, double phi0,
int stride_lon, int stride_lat, sharp_geom_info **geom_info)
{
const double pi=3.141592653589793238462643383279502884197;
double *theta=RALLOC(double,nrings);
int *nph=RALLOC(int,nrings);
double *phi0_=RALLOC(double,nrings);
ptrdiff_t *ofs=RALLOC(ptrdiff_t,nrings);
int *stride_=RALLOC(int,nrings);
for (int m=0; m<nrings; ++m)
{
theta[m]=pi*(2.*m+1.)/(2.*nrings-1.);
if (theta[m]>pi-1e-15) theta[m]=pi-1e-15;
nph[m]=ppring;
phi0_[m]=phi0;
ofs[m]=(ptrdiff_t)m*stride_lat;
stride_[m]=stride_lon;
}
sharp_make_geom_info (nrings, nph, ofs, stride_, phi0_, theta, NULL,
geom_info);
DEALLOC(theta);
DEALLOC(nph);
DEALLOC(phi0_);
DEALLOC(ofs);
DEALLOC(stride_);
}