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bertin |
/*
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* wcs.c
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*
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* High level driver routines.
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*
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*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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*
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* This file part of: AstrOmatic WCS library
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*
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235 |
bertin |
* Copyright: (C) 2000-2010 Emmanuel Bertin -- IAP/CNRS/UPMC
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* (C) 1995-1999 Mark Calabretta (original version)
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233 |
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*
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* Licenses: GNU General Public License
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*
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* AstrOmatic software is free software: you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, either version 3 of the
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* License, or (at your option) any later version.
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* AstrOmatic software is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with AstrOmatic software.
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* If not, see <http://www.gnu.org/licenses/>.
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*
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* Last modified: 10/10/2010
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*
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*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
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2 |
bertin |
/*=============================================================================
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*
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* WCSLIB - an implementation of the FITS WCS proposal.
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* Copyright (C) 1995-1999, Mark Calabretta
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*
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* This library is free software; you can redistribute it and/or modify it
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* under the terms of the GNU Library General Public License as published
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* by the Free Software Foundation; either version 2 of the License, or (at
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* your option) any later version.
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*
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* This library is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library
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* General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public License
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* along with this library; if not, write to the Free Software Foundation,
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* Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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* Correspondence concerning WCSLIB may be directed to:
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* Internet email: mcalabre@atnf.csiro.au
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* Postal address: Dr. Mark Calabretta,
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* Australia Telescope National Facility,
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* P.O. Box 76,
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* Epping, NSW, 2121,
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* AUSTRALIA
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*
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*=============================================================================
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*
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* C routines which implement the FITS World Coordinate System (WCS)
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* convention.
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*
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* Summary of routines
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* -------------------
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* wcsfwd() and wcsrev() are high level driver routines for the WCS linear
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* transformation, spherical coordinate transformation, and spherical
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* projection routines.
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*
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* Given either the celestial longitude or latitude plus an element of the
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* pixel coordinate a hybrid routine, wcsmix(), iteratively solves for the
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* unknown elements.
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*
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* An initialization routine, wcsset(), computes indices from the ctype
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* array but need not be called explicitly - see the explanation of
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* wcs.flag below.
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*
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*
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* Initialization routine; wcsset()
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* --------------------------------
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* Initializes elements of a wcsprm data structure which holds indices into
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* the coordinate arrays. Note that this routine need not be called directly;
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* it will be invoked by wcsfwd() and wcsrev() if the "flag" structure member
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* is anything other than a predefined magic value.
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*
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* Given:
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* naxis const int
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* Number of image axes.
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* ctype[][9]
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* const char
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* Coordinate axis types corresponding to the FITS
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* CTYPEn header cards.
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*
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* Returned:
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* wcs wcsprm* Indices for the celestial coordinates obtained
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* by parsing the ctype[] array (see below).
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*
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* Function return value:
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* int Error status
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* 0: Success.
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* 1: Inconsistent or unrecognized coordinate axis
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* types.
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*
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*
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* Forward transformation; wcsfwd()
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* --------------------------------
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* Compute the pixel coordinate for given world coordinates.
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*
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* Given:
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* ctype[][9]
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* const char
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* Coordinate axis types corresponding to the FITS
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* CTYPEn header cards.
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*
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* Given or returned:
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* wcs wcsprm* Indices for the celestial coordinates obtained
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* by parsing the ctype[] array (see below).
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*
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* Given:
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* world const double[]
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* World coordinates. world[wcs->lng] and
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* world[wcs->lat] are the celestial longitude and
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* latitude, in degrees.
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*
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* Given:
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* crval const double[]
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* Coordinate reference values corresponding to the FITS
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* CRVALn header cards.
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*
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* Given and returned:
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* cel celprm* Spherical coordinate transformation parameters (usage
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* is described in the prologue to "cel.c").
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*
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* Returned:
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* phi, double* Longitude and latitude in the native coordinate
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* theta system of the projection, in degrees.
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*
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* Given and returned:
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* prj prjprm* Projection parameters (usage is described in the
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* prologue to "proj.c").
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*
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* Returned:
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* imgcrd double[] Image coordinate. imgcrd[wcs->lng] and
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* imgcrd[wcs->lat] are the projected x-, and
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* y-coordinates, in "degrees". For quadcube
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* projections with a CUBEFACE axis the face number is
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* also returned in imgcrd[wcs->cubeface].
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*
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* Given and returned:
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* lin linprm* Linear transformation parameters (usage is described
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* in the prologue to "lin.c").
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*
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* Returned:
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* pixcrd double[] Pixel coordinate.
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*
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* Function return value:
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* int Error status
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* 0: Success.
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* 1: Invalid coordinate transformation parameters.
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* 2: Invalid projection parameters.
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* 3: Invalid world coordinate.
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* 4: Invalid linear transformation parameters.
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*
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*
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* Reverse transformation; wcsrev()
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* --------------------------------
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* Compute world coordinates for a given pixel coordinate.
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*
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* Given:
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* ctype[][9]
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* const char
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* Coordinate axis types corresponding to the FITS
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* CTYPEn header cards.
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*
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* Given or returned:
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* wcs wcsprm* Indices for the celestial coordinates obtained
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* by parsing the ctype[] array (see below).
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*
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* Given:
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* pixcrd const double[]
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* Pixel coordinate.
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*
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* Given and returned:
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* lin linprm* Linear transformation parameters (usage is described
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* in the prologue to "lin.c").
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*
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* Returned:
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* imgcrd double[] Image coordinate. imgcrd[wcs->lng] and
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* imgcrd[wcs->lat] are the projected x-, and
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* y-coordinates, in "degrees".
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*
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* Given and returned:
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* prj prjprm* Projection parameters (usage is described in the
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* prologue to "proj.c").
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*
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* Returned:
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* phi, double* Longitude and latitude in the native coordinate
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* theta system of the projection, in degrees.
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*
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* Given:
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* crval const double[]
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* Coordinate reference values corresponding to the FITS
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* CRVALn header cards.
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*
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* Given and returned:
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* cel celprm* Spherical coordinate transformation parameters
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* (usage is described in the prologue to "cel.c").
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*
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* Returned:
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* world double[] World coordinates. world[wcs->lng] and
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* world[wcs->lat] are the celestial longitude and
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* latitude, in degrees.
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*
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* Function return value:
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* int Error status
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* 0: Success.
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* 1: Invalid coordinate transformation parameters.
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* 2: Invalid projection parameters.
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* 3: Invalid pixel coordinate.
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* 4: Invalid linear transformation parameters.
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*
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*
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* Hybrid transformation; wcsmix()
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* -------------------------------
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* Given either the celestial longitude or latitude plus an element of the
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* pixel coordinate solve for the remaining elements by iterating on the
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* unknown celestial coordinate element using wcsfwd().
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*
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* Given:
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* ctype[][9]
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* const char
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* Coordinate axis types corresponding to the FITS
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* CTYPEn header cards.
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*
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* Given or returned:
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* wcs wcsprm* Indices for the celestial coordinates obtained
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* by parsing the ctype[] array (see below).
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*
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* Given:
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* mixpix const int
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* Which element of the pixel coordinate is given.
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* mixcel const int
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* Which element of the celestial coordinate is
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* given:
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* 1: Celestial longitude is given in
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* world[wcs->lng], latitude returned in
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* world[wcs->lat].
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* 2: Celestial latitude is given in
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* world[wcs->lat], longitude returned in
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* world[wcs->lng].
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* vspan[2] const double
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* Solution interval for the celestial coordinate, in
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* degrees.
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* vstep const double
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* Step size for solution search, in degrees. If zero,
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* a sensible, although perhaps non-optimal default will
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* be used.
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* viter int
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* If a solution is not found then the step size will be
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* halved and the search recommenced. viter controls
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* how many times the step size is halved. The allowed
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* range is 5 - 10.
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*
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* Given and returned:
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* world double[] World coordinates. world[wcs->lng] and
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* world[wcs->lat] are the celestial longitude and
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* latitude, in degrees. Which is given and which
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* returned depends on the value of mixcel. All other
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* elements are given.
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*
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* Given:
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* crval const double[]
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* Coordinate reference values corresponding to the FITS
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* CRVALn header cards.
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*
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* Given and returned:
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* cel celprm* Spherical coordinate transformation parameters
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* (usage is described in the prologue to "cel.c").
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| 277 |
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*
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* Returned:
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| 279 |
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* phi, double* Longitude and latitude in the native coordinate
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| 280 |
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* theta system of the projection, in degrees.
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| 281 |
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*
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| 282 |
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* Given and returned:
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| 283 |
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* prj prjprm* Projection parameters (usage is described in the
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| 284 |
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* prologue to "proj.c").
|
| 285 |
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*
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| 286 |
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* Returned:
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| 287 |
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* imgcrd double[] Image coordinate. imgcrd[wcs->lng] and
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| 288 |
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* imgcrd[wcs->lat] are the projected x-, and
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| 289 |
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* y-coordinates, in "degrees".
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| 290 |
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*
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| 291 |
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* Given and returned:
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| 292 |
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* lin linprm* Linear transformation parameters (usage is described
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| 293 |
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* in the prologue to "lin.c").
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| 294 |
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*
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| 295 |
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* Given and returned:
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| 296 |
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* pixcrd double[] Pixel coordinate. The element indicated by mixpix is
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| 297 |
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* given and the remaining elements are returned.
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| 298 |
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*
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| 299 |
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* Function return value:
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| 300 |
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* int Error status
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| 301 |
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* 0: Success.
|
| 302 |
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* 1: Invalid coordinate transformation parameters.
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| 303 |
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* 2: Invalid projection parameters.
|
| 304 |
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* 3: Coordinate transformation error.
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| 305 |
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* 4: Invalid linear transformation parameters.
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| 306 |
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* 5: No solution found in the specified interval.
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| 307 |
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*
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| 308 |
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*
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| 309 |
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* Notes
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| 310 |
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* -----
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| 311 |
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* 1) The CTYPEn must in be upper case and there must be 0 or 1 pair of
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| 312 |
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* matched celestial axis types. The ctype[][9] should be padded with
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| 313 |
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* blanks on the right and null-terminated.
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| 314 |
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*
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| 315 |
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* 2) Elements of the crval[] array which correspond to celestial axes are
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| 316 |
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* ignored, the reference coordinate values in cel->ref[0] and
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| 317 |
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* cel->ref[1] are the ones used.
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| 318 |
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*
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| 319 |
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* 3) These functions recognize the NCP projection and convert it to the
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| 320 |
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* equivalent SIN projection.
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| 321 |
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*
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| 322 |
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* 4) The quadcube projections (CSC, QSC, TSC) may be represented in FITS in
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| 323 |
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* either of two ways:
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| 324 |
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*
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| 325 |
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* a) The six faces may be laid out in one plane and numbered as
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| 326 |
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* follows:
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| 327 |
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*
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| 328 |
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* 0
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| 329 |
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*
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| 330 |
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* 4 3 2 1 4 3 2
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| 331 |
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*
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| 332 |
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* 5
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| 333 |
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*
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| 334 |
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* Faces 2, 3 and 4 may appear on one side or the other (or both).
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| 335 |
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* The forward routines map faces 2, 3 and 4 to the left but the
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| 336 |
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* inverse routines accept them on either side.
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| 337 |
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*
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| 338 |
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* b) The "COBE" convention in which the six faces are stored in a
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| 339 |
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* three-dimensional structure using a "CUBEFACE" axis indexed from
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| 340 |
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* 0 to 5 as above.
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| 341 |
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*
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| 342 |
|
|
* These routines support both methods; wcsset() determines which is
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| 343 |
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* being used by the presence or absence of a CUBEFACE axis in ctype[].
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| 344 |
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* wcsfwd() and wcsrev() translate the CUBEFACE axis representation to
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| 345 |
|
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* the single plane representation understood by the lower-level WCSLIB
|
| 346 |
|
|
* projection routines.
|
| 347 |
|
|
*
|
| 348 |
|
|
*
|
| 349 |
|
|
* WCS indexing parameters
|
| 350 |
|
|
* -----------------------
|
| 351 |
|
|
* The wcsprm struct consists of the following:
|
| 352 |
|
|
*
|
| 353 |
|
|
* int flag
|
| 354 |
|
|
* The wcsprm struct contains indexes and other information derived
|
| 355 |
|
|
* from the CTYPEn. Whenever any of the ctype[] are set or changed
|
| 356 |
|
|
* this flag must be set to zero to signal the initialization routine,
|
| 357 |
|
|
* wcsset() to redetermine the indices. The flag is set to 999 if
|
| 358 |
|
|
* there is no celestial axis pair in the CTYPEn.
|
| 359 |
|
|
*
|
| 360 |
|
|
* char pcode[4]
|
| 361 |
|
|
* The WCS projection code.
|
| 362 |
|
|
*
|
| 363 |
|
|
* char lngtyp[5], lattyp[5]
|
| 364 |
|
|
* WCS celestial axis types.
|
| 365 |
|
|
*
|
| 366 |
|
|
* int lng,lat
|
| 367 |
|
|
* Indices into the imgcrd[], and world[] arrays as described above.
|
| 368 |
|
|
* These may also serve as indices for the celestial longitude and
|
| 369 |
|
|
* latitude axes in the pixcrd[] array provided that the PC matrix
|
| 370 |
|
|
* does not transpose axes.
|
| 371 |
|
|
*
|
| 372 |
|
|
* int cubeface
|
| 373 |
|
|
* Index into the pixcrd[] array for the CUBEFACE axis. This is
|
| 374 |
|
|
* optionally used for the quadcube projections where each cube face is
|
| 375 |
|
|
* stored on a separate axis.
|
| 376 |
|
|
*
|
| 377 |
|
|
*
|
| 378 |
|
|
* wcsmix() algorithm
|
| 379 |
|
|
* ------------------
|
| 380 |
|
|
* Initially the specified solution interval is checked to see if it's a
|
| 381 |
|
|
* "crossing" interval. If it isn't, a search is made for a crossing
|
| 382 |
|
|
* solution by iterating on the unknown celestial coordinate starting at
|
| 383 |
|
|
* the upper limit of the solution interval and decrementing by the
|
| 384 |
|
|
* specified step size. A crossing is indicated if the trial value of the
|
| 385 |
|
|
* pixel coordinate steps through the value specified. If a crossing
|
| 386 |
|
|
* interval is found then the solution is determined by a modified form of
|
| 387 |
|
|
* "regula falsi" division of the crossing interval. If no crossing
|
| 388 |
|
|
* interval was found within the specified solution interval then a search
|
| 389 |
|
|
* is made for a "non-crossing" solution as may arise from a point of
|
| 390 |
|
|
* tangency. The process is complicated by having to make allowance for
|
| 391 |
|
|
* the discontinuities that occur in all map projections.
|
| 392 |
|
|
*
|
| 393 |
|
|
* Once one solution has been determined others may be found by subsequent
|
| 394 |
|
|
* invokations of wcsmix() with suitably restricted solution intervals.
|
| 395 |
|
|
*
|
| 396 |
|
|
* Note the circumstance which arises when the solution point lies at a
|
| 397 |
|
|
* native pole of a projection in which the pole is represented as a
|
| 398 |
|
|
* finite curve, for example the zenithals and conics. In such cases two
|
| 399 |
|
|
* or more valid solutions may exist but WCSMIX only ever returns one.
|
| 400 |
|
|
*
|
| 401 |
|
|
* Because of its generality wcsmix() is very compute-intensive. For
|
| 402 |
|
|
* compute-limited applications more efficient special-case solvers could
|
| 403 |
|
|
* be written for simple projections, for example non-oblique cylindrical
|
| 404 |
|
|
* projections.
|
| 405 |
|
|
*
|
| 406 |
|
|
* Author: Mark Calabretta, Australia Telescope National Facility
|
| 407 |
|
|
* $Id: wcs.c,v 1.1.1.1 2002/03/15 16:33:26 bertin Exp $
|
| 408 |
|
|
*===========================================================================*/
|
| 409 |
|
|
|
| 410 |
|
|
#ifdef HAVE_CONFIG_H
|
| 411 |
|
|
#include "config.h"
|
| 412 |
|
|
#endif
|
| 413 |
|
|
|
| 414 |
|
|
#ifdef HAVE_MATHIMF_H
|
| 415 |
|
|
#include <mathimf.h>
|
| 416 |
|
|
#else
|
| 417 |
|
|
#include <math.h>
|
| 418 |
|
|
#endif
|
| 419 |
|
|
#include "stdio.h"
|
| 420 |
|
|
#include "string.h"
|
| 421 |
|
|
#include "wcsmath.h"
|
| 422 |
|
|
#include "wcstrig.h"
|
| 423 |
|
|
#include "sph.h"
|
| 424 |
|
|
#include "wcs.h"
|
| 425 |
|
|
|
| 426 |
|
|
/* Map error number to error message for each function. */
|
| 427 |
|
|
const char *wcsset_errmsg[] = {
|
| 428 |
|
|
0,
|
| 429 |
|
|
"Inconsistent or unrecognized coordinate axis types"};
|
| 430 |
|
|
|
| 431 |
|
|
const char *wcsfwd_errmsg[] = {
|
| 432 |
|
|
0,
|
| 433 |
|
|
"Invalid coordinate transformation parameters",
|
| 434 |
|
|
"Invalid projection parameters",
|
| 435 |
|
|
"Invalid world coordinate",
|
| 436 |
|
|
"Invalid linear transformation parameters"};
|
| 437 |
|
|
|
| 438 |
|
|
const char *wcsrev_errmsg[] = {
|
| 439 |
|
|
0,
|
| 440 |
|
|
"Invalid coordinate transformation parameters",
|
| 441 |
|
|
"Invalid projection parameters",
|
| 442 |
|
|
"Invalid pixel coordinate",
|
| 443 |
|
|
"Invalid linear transformation parameters"};
|
| 444 |
|
|
|
| 445 |
|
|
const char *wcsmix_errmsg[] = {
|
| 446 |
|
|
0,
|
| 447 |
|
|
"Invalid coordinate transformation parameters",
|
| 448 |
|
|
"Invalid projection parameters",
|
| 449 |
|
|
"Coordinate transformation error",
|
| 450 |
|
|
"Invalid linear transformation parameters",
|
| 451 |
|
|
"No solution found in the specified interval"};
|
| 452 |
|
|
|
| 453 |
|
|
|
| 454 |
|
|
#define wcs_signbit(X) ((X) < 0.0 ? 1 : 0)
|
| 455 |
|
|
|
| 456 |
|
|
int wcsset (naxis, ctype, wcs)
|
| 457 |
|
|
|
| 458 |
|
|
const int naxis;
|
| 459 |
|
|
const char ctype[][9];
|
| 460 |
|
|
struct wcsprm *wcs;
|
| 461 |
|
|
|
| 462 |
|
|
{
|
| 463 |
|
|
int j, k, *ndx;
|
| 464 |
|
|
char requir[9];
|
| 465 |
|
|
|
| 466 |
|
|
strcpy(wcs->pcode, "");
|
| 467 |
|
|
strcpy(requir, "");
|
| 468 |
|
|
wcs->lng = -1;
|
| 469 |
|
|
ndx = &wcs->lng; /* to satisfy gcc -Wall */
|
| 470 |
|
|
wcs->lat = -1;
|
| 471 |
|
|
wcs->cubeface = -1;
|
| 472 |
|
|
|
| 473 |
|
|
for (j = 0; j < naxis; j++) {
|
| 474 |
|
|
if (ctype[j][4] != '-') {
|
| 475 |
|
|
if (strcmp(ctype[j], "CUBEFACE") == 0) {
|
| 476 |
|
|
if (wcs->cubeface == -1) {
|
| 477 |
|
|
wcs->cubeface = j;
|
| 478 |
|
|
} else {
|
| 479 |
|
|
/* Multiple CUBEFACE axes! */
|
| 480 |
|
|
return 1;
|
| 481 |
|
|
}
|
| 482 |
|
|
}
|
| 483 |
|
|
continue;
|
| 484 |
|
|
}
|
| 485 |
|
|
|
| 486 |
|
|
/* Got an axis qualifier, is it a recognized WCS projection? */
|
| 487 |
|
|
for (k = 0; k < npcode; k++) {
|
| 488 |
|
|
if (strncmp(&ctype[j][5], pcodes[k], 3) == 0) break;
|
| 489 |
|
|
}
|
| 490 |
|
|
|
| 491 |
|
|
if (k == npcode) {
|
| 492 |
|
|
/* Allow NCP to pass (will be converted to SIN later). */
|
| 493 |
|
|
if (strncmp(&ctype[j][5], "NCP", 3)) continue;
|
| 494 |
|
|
}
|
| 495 |
|
|
|
| 496 |
|
|
/* Parse the celestial axis type. */
|
| 497 |
|
|
if (strcmp(wcs->pcode, "") == 0) {
|
| 498 |
|
|
sprintf(wcs->pcode, "%.3s", &ctype[j][5]);
|
| 499 |
|
|
|
| 500 |
|
|
if (strncmp(ctype[j], "RA--", 4) == 0) {
|
| 501 |
|
|
wcs->lng = j;
|
| 502 |
|
|
strcpy(wcs->lngtyp, "RA");
|
| 503 |
|
|
strcpy(wcs->lattyp, "DEC");
|
| 504 |
|
|
ndx = &wcs->lat;
|
| 505 |
|
|
sprintf(requir, "DEC--%s", wcs->pcode);
|
| 506 |
|
|
} else if (strncmp(ctype[j], "DEC-", 4) == 0) {
|
| 507 |
|
|
wcs->lat = j;
|
| 508 |
|
|
strcpy(wcs->lngtyp, "RA");
|
| 509 |
|
|
strcpy(wcs->lattyp, "DEC");
|
| 510 |
|
|
ndx = &wcs->lng;
|
| 511 |
|
|
sprintf(requir, "RA---%s", wcs->pcode);
|
| 512 |
|
|
} else if (strncmp(&ctype[j][1], "LON", 3) == 0) {
|
| 513 |
|
|
wcs->lng = j;
|
| 514 |
|
|
sprintf(wcs->lngtyp, "%cLON", ctype[j][0]);
|
| 515 |
|
|
sprintf(wcs->lattyp, "%cLAT", ctype[j][0]);
|
| 516 |
|
|
ndx = &wcs->lat;
|
| 517 |
|
|
sprintf(requir, "%s-%s", wcs->lattyp, wcs->pcode);
|
| 518 |
|
|
} else if (strncmp(&ctype[j][1], "LAT", 3) == 0) {
|
| 519 |
|
|
wcs->lat = j;
|
| 520 |
|
|
sprintf(wcs->lngtyp, "%cLON", ctype[j][0]);
|
| 521 |
|
|
sprintf(wcs->lattyp, "%cLAT", ctype[j][0]);
|
| 522 |
|
|
ndx = &wcs->lng;
|
| 523 |
|
|
sprintf(requir, "%s-%s", wcs->lngtyp, wcs->pcode);
|
| 524 |
|
|
} else {
|
| 525 |
|
|
/* Unrecognized celestial type. */
|
| 526 |
|
|
return 1;
|
| 527 |
|
|
}
|
| 528 |
|
|
} else {
|
| 529 |
|
|
if (strncmp(ctype[j], requir, 8) != 0) {
|
| 530 |
|
|
/* Inconsistent projection types. */
|
| 531 |
|
|
return 1;
|
| 532 |
|
|
}
|
| 533 |
|
|
|
| 534 |
|
|
*ndx = j;
|
| 535 |
|
|
strcpy(requir, "");
|
| 536 |
|
|
}
|
| 537 |
|
|
}
|
| 538 |
|
|
|
| 539 |
|
|
if (strcmp(requir, "")) {
|
| 540 |
|
|
/* Unmatched celestial axis. */
|
| 541 |
|
|
return 1;
|
| 542 |
|
|
}
|
| 543 |
|
|
|
| 544 |
|
|
if (strcmp(wcs->pcode, "")) {
|
| 545 |
|
|
wcs->flag = WCSSET;
|
| 546 |
|
|
} else {
|
| 547 |
|
|
/* Signal for no celestial axis pair. */
|
| 548 |
|
|
wcs->flag = 999;
|
| 549 |
|
|
}
|
| 550 |
|
|
|
| 551 |
|
|
return 0;
|
| 552 |
|
|
}
|
| 553 |
|
|
|
| 554 |
|
|
/*--------------------------------------------------------------------------*/
|
| 555 |
|
|
|
| 556 |
|
|
int wcsfwd(ctype, wcs, world, crval, cel, phi, theta, prj, imgcrd, lin,
|
| 557 |
|
|
pixcrd)
|
| 558 |
|
|
|
| 559 |
|
|
const char ctype[][9];
|
| 560 |
|
|
struct wcsprm* wcs;
|
| 561 |
|
|
const double world[];
|
| 562 |
|
|
const double crval[];
|
| 563 |
|
|
struct celprm *cel;
|
| 564 |
|
|
double *phi, *theta;
|
| 565 |
|
|
struct prjprm *prj;
|
| 566 |
|
|
double imgcrd[];
|
| 567 |
|
|
struct linprm *lin;
|
| 568 |
|
|
double pixcrd[];
|
| 569 |
|
|
|
| 570 |
|
|
{
|
| 571 |
|
|
int err, j;
|
| 572 |
|
|
double offset;
|
| 573 |
|
|
|
| 574 |
|
|
/* Initialize if required. */
|
| 575 |
|
|
if (wcs->flag != WCSSET) {
|
| 576 |
|
|
if (wcsset(lin->naxis, ctype, wcs)) return 1;
|
| 577 |
|
|
}
|
| 578 |
|
|
|
| 579 |
|
|
/* Convert to relative physical coordinates. */
|
| 580 |
|
|
for (j = 0; j < lin->naxis; j++) {
|
| 581 |
|
|
if (j == wcs->lng) continue;
|
| 582 |
|
|
if (j == wcs->lat) continue;
|
| 583 |
|
|
imgcrd[j] = world[j] - crval[j];
|
| 584 |
|
|
}
|
| 585 |
|
|
|
| 586 |
|
|
if (wcs->flag != 999) {
|
| 587 |
|
|
/* Compute projected coordinates. */
|
| 588 |
|
|
if (strcmp(wcs->pcode, "NCP") == 0) {
|
| 589 |
|
|
/* Convert NCP to SIN. */
|
| 590 |
|
|
if (cel->ref[2] == 0.0) {
|
| 591 |
|
|
return 2;
|
| 592 |
|
|
}
|
| 593 |
|
|
strcpy(wcs->pcode, "SIN");
|
| 594 |
|
|
prj->p[1] = 0.0;
|
| 595 |
|
|
prj->p[2] = wcs_cosd(cel->ref[2])/wcs_sind(cel->ref[2]);
|
| 596 |
|
|
prj->flag = 0;
|
| 597 |
|
|
}
|
| 598 |
|
|
|
| 599 |
|
|
if ((err = celfwd(wcs->pcode, world[wcs->lng], world[wcs->lat], cel,
|
| 600 |
|
|
phi, theta, prj, &imgcrd[wcs->lng], &imgcrd[wcs->lat]))) {
|
| 601 |
|
|
return err;
|
| 602 |
|
|
}
|
| 603 |
|
|
|
| 604 |
|
|
/* Do we have a CUBEFACE axis? */
|
| 605 |
|
|
if (wcs->cubeface != -1) {
|
| 606 |
|
|
/* Separation between faces. */
|
| 607 |
|
|
if (prj->r0 == 0.0) {
|
| 608 |
|
|
offset = 90.0;
|
| 609 |
|
|
} else {
|
| 610 |
|
|
offset = prj->r0*PI/2.0;
|
| 611 |
|
|
}
|
| 612 |
|
|
|
| 613 |
|
|
/* Stack faces in a cube. */
|
| 614 |
|
|
if (imgcrd[wcs->lat] < -0.5*offset) {
|
| 615 |
|
|
imgcrd[wcs->lat] += offset;
|
| 616 |
|
|
imgcrd[wcs->cubeface] = 5.0;
|
| 617 |
|
|
} else if (imgcrd[wcs->lat] > 0.5*offset) {
|
| 618 |
|
|
imgcrd[wcs->lat] -= offset;
|
| 619 |
|
|
imgcrd[wcs->cubeface] = 0.0;
|
| 620 |
|
|
} else if (imgcrd[wcs->lng] > 2.5*offset) {
|
| 621 |
|
|
imgcrd[wcs->lng] -= 3.0*offset;
|
| 622 |
|
|
imgcrd[wcs->cubeface] = 4.0;
|
| 623 |
|
|
} else if (imgcrd[wcs->lng] > 1.5*offset) {
|
| 624 |
|
|
imgcrd[wcs->lng] -= 2.0*offset;
|
| 625 |
|
|
imgcrd[wcs->cubeface] = 3.0;
|
| 626 |
|
|
} else if (imgcrd[wcs->lng] > 0.5*offset) {
|
| 627 |
|
|
imgcrd[wcs->lng] -= offset;
|
| 628 |
|
|
imgcrd[wcs->cubeface] = 2.0;
|
| 629 |
|
|
} else {
|
| 630 |
|
|
imgcrd[wcs->cubeface] = 1.0;
|
| 631 |
|
|
}
|
| 632 |
|
|
}
|
| 633 |
|
|
}
|
| 634 |
|
|
|
| 635 |
|
|
/* Apply forward linear transformation. */
|
| 636 |
|
|
if (linfwd(imgcrd, lin, pixcrd)) {
|
| 637 |
|
|
return 4;
|
| 638 |
|
|
}
|
| 639 |
|
|
|
| 640 |
|
|
return 0;
|
| 641 |
|
|
}
|
| 642 |
|
|
|
| 643 |
|
|
/*--------------------------------------------------------------------------*/
|
| 644 |
|
|
|
| 645 |
|
|
int wcsrev(ctype, wcs, pixcrd, lin, imgcrd, prj, phi, theta, crval, cel,
|
| 646 |
|
|
world)
|
| 647 |
|
|
|
| 648 |
|
|
const char ctype[][9];
|
| 649 |
|
|
struct wcsprm *wcs;
|
| 650 |
|
|
const double pixcrd[];
|
| 651 |
|
|
struct linprm *lin;
|
| 652 |
|
|
double imgcrd[];
|
| 653 |
|
|
struct prjprm *prj;
|
| 654 |
|
|
double *phi, *theta;
|
| 655 |
|
|
const double crval[];
|
| 656 |
|
|
struct celprm *cel;
|
| 657 |
|
|
double world[];
|
| 658 |
|
|
|
| 659 |
|
|
{
|
| 660 |
|
|
int err, face, j;
|
| 661 |
|
|
double offset;
|
| 662 |
|
|
|
| 663 |
|
|
/* Initialize if required. */
|
| 664 |
|
|
if (wcs->flag != WCSSET) {
|
| 665 |
|
|
if (wcsset(lin->naxis, ctype, wcs)) return 1;
|
| 666 |
|
|
}
|
| 667 |
|
|
|
| 668 |
|
|
/* Apply reverse linear transformation. */
|
| 669 |
|
|
if (linrev(pixcrd, lin, imgcrd)) {
|
| 670 |
|
|
return 4;
|
| 671 |
|
|
}
|
| 672 |
|
|
|
| 673 |
|
|
/* Convert to world coordinates. */
|
| 674 |
|
|
for (j = 0; j < lin->naxis; j++) {
|
| 675 |
|
|
if (j == wcs->lng) continue;
|
| 676 |
|
|
if (j == wcs->lat) continue;
|
| 677 |
|
|
world[j] = imgcrd[j] + crval[j];
|
| 678 |
|
|
}
|
| 679 |
|
|
|
| 680 |
|
|
|
| 681 |
|
|
if (wcs->flag != 999) {
|
| 682 |
|
|
/* Do we have a CUBEFACE axis? */
|
| 683 |
|
|
if (wcs->cubeface != -1) {
|
| 684 |
|
|
face = (int)(imgcrd[wcs->cubeface] + 0.5);
|
| 685 |
|
|
if (fabs(imgcrd[wcs->cubeface]-face) > 1e-10) {
|
| 686 |
|
|
return 3;
|
| 687 |
|
|
}
|
| 688 |
|
|
|
| 689 |
|
|
/* Separation between faces. */
|
| 690 |
|
|
if (prj->r0 == 0.0) {
|
| 691 |
|
|
offset = 90.0;
|
| 692 |
|
|
} else {
|
| 693 |
|
|
offset = prj->r0*PI/2.0;
|
| 694 |
|
|
}
|
| 695 |
|
|
|
| 696 |
|
|
/* Lay out faces in a plane. */
|
| 697 |
|
|
switch (face) {
|
| 698 |
|
|
case 0:
|
| 699 |
|
|
imgcrd[wcs->lat] += offset;
|
| 700 |
|
|
break;
|
| 701 |
|
|
case 1:
|
| 702 |
|
|
break;
|
| 703 |
|
|
case 2:
|
| 704 |
|
|
imgcrd[wcs->lng] += offset;
|
| 705 |
|
|
break;
|
| 706 |
|
|
case 3:
|
| 707 |
|
|
imgcrd[wcs->lng] += offset*2;
|
| 708 |
|
|
break;
|
| 709 |
|
|
case 4:
|
| 710 |
|
|
imgcrd[wcs->lng] += offset*3;
|
| 711 |
|
|
break;
|
| 712 |
|
|
case 5:
|
| 713 |
|
|
imgcrd[wcs->lat] -= offset;
|
| 714 |
|
|
break;
|
| 715 |
|
|
default:
|
| 716 |
|
|
return 3;
|
| 717 |
|
|
}
|
| 718 |
|
|
}
|
| 719 |
|
|
|
| 720 |
|
|
/* Compute celestial coordinates. */
|
| 721 |
|
|
if (strcmp(wcs->pcode, "NCP") == 0) {
|
| 722 |
|
|
/* Convert NCP to SIN. */
|
| 723 |
|
|
if (cel->ref[2] == 0.0) {
|
| 724 |
|
|
return 2;
|
| 725 |
|
|
}
|
| 726 |
|
|
|
| 727 |
|
|
strcpy(wcs->pcode, "SIN");
|
| 728 |
|
|
prj->p[1] = 0.0;
|
| 729 |
|
|
prj->p[2] = wcs_cosd(cel->ref[2])/wcs_sind(cel->ref[2]);
|
| 730 |
|
|
prj->flag = 0;
|
| 731 |
|
|
}
|
| 732 |
|
|
|
| 733 |
|
|
if ((err = celrev(wcs->pcode, imgcrd[wcs->lng], imgcrd[wcs->lat], prj,
|
| 734 |
|
|
phi, theta, cel, &world[wcs->lng], &world[wcs->lat]))) {
|
| 735 |
|
|
return err;
|
| 736 |
|
|
}
|
| 737 |
|
|
}
|
| 738 |
|
|
|
| 739 |
|
|
return 0;
|
| 740 |
|
|
}
|
| 741 |
|
|
|
| 742 |
|
|
/*--------------------------------------------------------------------------*/
|
| 743 |
|
|
|
| 744 |
|
|
int wcsmix(ctype, wcs, mixpix, mixcel, vspan, vstep, viter, world, crval, cel,
|
| 745 |
|
|
phi, theta, prj, imgcrd, lin, pixcrd)
|
| 746 |
|
|
|
| 747 |
|
|
const char ctype[][9];
|
| 748 |
|
|
struct wcsprm *wcs;
|
| 749 |
|
|
const int mixpix, mixcel;
|
| 750 |
|
|
const double vspan[2], vstep;
|
| 751 |
|
|
int viter;
|
| 752 |
|
|
double world[];
|
| 753 |
|
|
const double crval[];
|
| 754 |
|
|
struct celprm *cel;
|
| 755 |
|
|
double *phi, *theta;
|
| 756 |
|
|
struct prjprm *prj;
|
| 757 |
|
|
double imgcrd[];
|
| 758 |
|
|
struct linprm *lin;
|
| 759 |
|
|
double pixcrd[];
|
| 760 |
|
|
|
| 761 |
|
|
{
|
| 762 |
|
|
const int niter = 60;
|
| 763 |
|
|
int crossed, err, istep, iter, j, k, nstep, retry;
|
| 764 |
|
|
const double tol = 1.0e-10;
|
| 765 |
|
|
double lambda, span[2], step;
|
| 766 |
|
|
double pixmix;
|
| 767 |
|
|
double lng, lng0, lng0m, lng1, lng1m;
|
| 768 |
|
|
double lat, lat0, lat0m, lat1, lat1m;
|
| 769 |
|
|
double d, d0, d0m, d1, d1m, dx;
|
| 770 |
|
|
double dabs, dmin, lmin;
|
| 771 |
|
|
double phi0, phi1;
|
| 772 |
|
|
struct celprm cel0;
|
| 773 |
|
|
|
| 774 |
|
|
/* Check vspan. */
|
| 775 |
|
|
if (vspan[0] <= vspan[1]) {
|
| 776 |
|
|
span[0] = vspan[0];
|
| 777 |
|
|
span[1] = vspan[1];
|
| 778 |
|
|
} else {
|
| 779 |
|
|
/* Swap them. */
|
| 780 |
|
|
span[0] = vspan[1];
|
| 781 |
|
|
span[1] = vspan[0];
|
| 782 |
|
|
}
|
| 783 |
|
|
|
| 784 |
|
|
/* Check vstep. */
|
| 785 |
|
|
step = fabs(vstep);
|
| 786 |
|
|
if (step == 0.0) {
|
| 787 |
|
|
step = (span[1] - span[0])/10.0;
|
| 788 |
|
|
if (step > 1.0 || step == 0.0) step = 1.0;
|
| 789 |
|
|
}
|
| 790 |
|
|
|
| 791 |
|
|
/* Check viter. */
|
| 792 |
|
|
nstep = viter;
|
| 793 |
|
|
if (nstep < 5) {
|
| 794 |
|
|
nstep = 5;
|
| 795 |
|
|
} else if (nstep > 10) {
|
| 796 |
|
|
nstep = 10;
|
| 797 |
|
|
}
|
| 798 |
|
|
|
| 799 |
|
|
/* Given pixel element. */
|
| 800 |
|
|
pixmix = pixcrd[mixpix];
|
| 801 |
|
|
|
| 802 |
|
|
dx = 0.0; /* to satisfy gcc -Wall */
|
| 803 |
|
|
/* Iterate on the step size. */
|
| 804 |
|
|
for (istep = 0; istep <= nstep; istep++) {
|
| 805 |
|
|
if (istep) step /= 2.0;
|
| 806 |
|
|
|
| 807 |
|
|
/* Iterate on the sky coordinate between the specified range. */
|
| 808 |
|
|
if (mixcel == 1) {
|
| 809 |
|
|
/* Celestial longitude is given. */
|
| 810 |
|
|
|
| 811 |
|
|
/* Check whether the solution interval is a crossing interval. */
|
| 812 |
|
|
lat0 = span[0];
|
| 813 |
|
|
world[wcs->lat] = lat0;
|
| 814 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, cel, phi, theta, prj,
|
| 815 |
|
|
imgcrd, lin, pixcrd))) {
|
| 816 |
|
|
return err;
|
| 817 |
|
|
}
|
| 818 |
|
|
d0 = pixcrd[mixpix] - pixmix;
|
| 819 |
|
|
|
| 820 |
|
|
dabs = fabs(d0);
|
| 821 |
|
|
if (dabs < tol) return 0;
|
| 822 |
|
|
|
| 823 |
|
|
lat1 = span[1];
|
| 824 |
|
|
world[wcs->lat] = lat1;
|
| 825 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, cel, phi, theta, prj,
|
| 826 |
|
|
imgcrd, lin, pixcrd))) {
|
| 827 |
|
|
return err;
|
| 828 |
|
|
}
|
| 829 |
|
|
d1 = pixcrd[mixpix] - pixmix;
|
| 830 |
|
|
|
| 831 |
|
|
dabs = fabs(d1);
|
| 832 |
|
|
if (dabs < tol) return 0;
|
| 833 |
|
|
|
| 834 |
|
|
lmin = lat1;
|
| 835 |
|
|
dmin = dabs;
|
| 836 |
|
|
|
| 837 |
|
|
/* Check for a crossing point. */
|
| 838 |
|
|
if (wcs_signbit(d0) != wcs_signbit(d1)) {
|
| 839 |
|
|
crossed = 1;
|
| 840 |
|
|
dx = d1;
|
| 841 |
|
|
} else {
|
| 842 |
|
|
crossed = 0;
|
| 843 |
|
|
lat0 = span[1];
|
| 844 |
|
|
}
|
| 845 |
|
|
|
| 846 |
|
|
for (retry = 0; retry < 4; retry++) {
|
| 847 |
|
|
/* Refine the solution interval. */
|
| 848 |
|
|
while (lat0 > span[0]) {
|
| 849 |
|
|
lat0 -= step;
|
| 850 |
|
|
if (lat0 < span[0]) lat0 = span[0];
|
| 851 |
|
|
world[wcs->lat] = lat0;
|
| 852 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, cel, phi, theta,
|
| 853 |
|
|
prj, imgcrd, lin, pixcrd))) {
|
| 854 |
|
|
return err;
|
| 855 |
|
|
}
|
| 856 |
|
|
d0 = pixcrd[mixpix] - pixmix;
|
| 857 |
|
|
|
| 858 |
|
|
/* Check for a solution. */
|
| 859 |
|
|
dabs = fabs(d0);
|
| 860 |
|
|
if (dabs < tol) return 0;
|
| 861 |
|
|
|
| 862 |
|
|
/* Record the point of closest approach. */
|
| 863 |
|
|
if (dabs < dmin) {
|
| 864 |
|
|
lmin = lat0;
|
| 865 |
|
|
dmin = dabs;
|
| 866 |
|
|
}
|
| 867 |
|
|
|
| 868 |
|
|
/* Check for a crossing point. */
|
| 869 |
|
|
if (wcs_signbit(d0) != wcs_signbit(d1)) {
|
| 870 |
|
|
crossed = 2;
|
| 871 |
|
|
dx = d0;
|
| 872 |
|
|
break;
|
| 873 |
|
|
}
|
| 874 |
|
|
|
| 875 |
|
|
/* Advance to the next subinterval. */
|
| 876 |
|
|
lat1 = lat0;
|
| 877 |
|
|
d1 = d0;
|
| 878 |
|
|
}
|
| 879 |
|
|
|
| 880 |
|
|
if (crossed) {
|
| 881 |
|
|
/* A crossing point was found. */
|
| 882 |
|
|
for (iter = 0; iter < niter; iter++) {
|
| 883 |
|
|
/* Use regula falsi division of the interval. */
|
| 884 |
|
|
lambda = d0/(d0-d1);
|
| 885 |
|
|
if (lambda < 0.1) {
|
| 886 |
|
|
lambda = 0.1;
|
| 887 |
|
|
} else if (lambda > 0.9) {
|
| 888 |
|
|
lambda = 0.9;
|
| 889 |
|
|
}
|
| 890 |
|
|
|
| 891 |
|
|
lat = lat0 + lambda*(lat1 - lat0);
|
| 892 |
|
|
world[wcs->lat] = lat;
|
| 893 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, cel, phi, theta,
|
| 894 |
|
|
prj, imgcrd, lin, pixcrd))) {
|
| 895 |
|
|
return err;
|
| 896 |
|
|
}
|
| 897 |
|
|
d = pixcrd[mixpix] - pixmix;
|
| 898 |
|
|
|
| 899 |
|
|
/* Check for a solution. */
|
| 900 |
|
|
dabs = fabs(d);
|
| 901 |
|
|
if (dabs < tol) return 0;
|
| 902 |
|
|
|
| 903 |
|
|
/* Record the point of closest approach. */
|
| 904 |
|
|
if (dabs < dmin) {
|
| 905 |
|
|
lmin = lat;
|
| 906 |
|
|
dmin = dabs;
|
| 907 |
|
|
}
|
| 908 |
|
|
|
| 909 |
|
|
if (wcs_signbit(d0) == wcs_signbit(d)) {
|
| 910 |
|
|
lat0 = lat;
|
| 911 |
|
|
d0 = d;
|
| 912 |
|
|
} else {
|
| 913 |
|
|
lat1 = lat;
|
| 914 |
|
|
d1 = d;
|
| 915 |
|
|
}
|
| 916 |
|
|
}
|
| 917 |
|
|
|
| 918 |
|
|
/* No convergence, must have been a discontinuity. */
|
| 919 |
|
|
if (crossed == 1) lat0 = span[1];
|
| 920 |
|
|
lat1 = lat0;
|
| 921 |
|
|
d1 = dx;
|
| 922 |
|
|
crossed = 0;
|
| 923 |
|
|
|
| 924 |
|
|
} else {
|
| 925 |
|
|
/* No crossing point; look for a tangent point. */
|
| 926 |
|
|
if (lmin == span[0]) break;
|
| 927 |
|
|
if (lmin == span[1]) break;
|
| 928 |
|
|
|
| 929 |
|
|
lat = lmin;
|
| 930 |
|
|
lat0 = lat - step;
|
| 931 |
|
|
if (lat0 < span[0]) lat0 = span[0];
|
| 932 |
|
|
lat1 = lat + step;
|
| 933 |
|
|
if (lat1 > span[1]) lat1 = span[1];
|
| 934 |
|
|
|
| 935 |
|
|
world[wcs->lat] = lat0;
|
| 936 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, cel, phi, theta,
|
| 937 |
|
|
prj, imgcrd, lin, pixcrd))) {
|
| 938 |
|
|
return err;
|
| 939 |
|
|
}
|
| 940 |
|
|
d0 = fabs(pixcrd[mixpix] - pixmix);
|
| 941 |
|
|
|
| 942 |
|
|
d = dmin;
|
| 943 |
|
|
|
| 944 |
|
|
world[wcs->lat] = lat1;
|
| 945 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, cel, phi, theta,
|
| 946 |
|
|
prj, imgcrd, lin, pixcrd))) {
|
| 947 |
|
|
return err;
|
| 948 |
|
|
}
|
| 949 |
|
|
d1 = fabs(pixcrd[mixpix] - pixmix);
|
| 950 |
|
|
|
| 951 |
|
|
for (iter = 0; iter < niter; iter++) {
|
| 952 |
|
|
lat0m = (lat0 + lat)/2.0;
|
| 953 |
|
|
world[wcs->lat] = lat0m;
|
| 954 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, cel, phi, theta,
|
| 955 |
|
|
prj, imgcrd, lin, pixcrd))) {
|
| 956 |
|
|
return err;
|
| 957 |
|
|
}
|
| 958 |
|
|
d0m = fabs(pixcrd[mixpix] - pixmix);
|
| 959 |
|
|
|
| 960 |
|
|
if (d0m < tol) return 0;
|
| 961 |
|
|
|
| 962 |
|
|
lat1m = (lat1 + lat)/2.0;
|
| 963 |
|
|
world[wcs->lat] = lat1m;
|
| 964 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, cel, phi, theta,
|
| 965 |
|
|
prj, imgcrd, lin, pixcrd))) {
|
| 966 |
|
|
return err;
|
| 967 |
|
|
}
|
| 968 |
|
|
d1m = fabs(pixcrd[mixpix] - pixmix);
|
| 969 |
|
|
|
| 970 |
|
|
if (d1m < tol) return 0;
|
| 971 |
|
|
|
| 972 |
|
|
if (d0m < d && d0m <= d1m) {
|
| 973 |
|
|
lat1 = lat;
|
| 974 |
|
|
d1 = d;
|
| 975 |
|
|
lat = lat0m;
|
| 976 |
|
|
d = d0m;
|
| 977 |
|
|
} else if (d1m < d) {
|
| 978 |
|
|
lat0 = lat;
|
| 979 |
|
|
d0 = d;
|
| 980 |
|
|
lat = lat1m;
|
| 981 |
|
|
d = d1m;
|
| 982 |
|
|
} else {
|
| 983 |
|
|
lat0 = lat0m;
|
| 984 |
|
|
d0 = d0m;
|
| 985 |
|
|
lat1 = lat1m;
|
| 986 |
|
|
d1 = d1m;
|
| 987 |
|
|
}
|
| 988 |
|
|
}
|
| 989 |
|
|
}
|
| 990 |
|
|
}
|
| 991 |
|
|
|
| 992 |
|
|
} else {
|
| 993 |
|
|
/* Celestial latitude is given. */
|
| 994 |
|
|
|
| 995 |
|
|
/* Check whether the solution interval is a crossing interval. */
|
| 996 |
|
|
lng0 = span[0];
|
| 997 |
|
|
world[wcs->lng] = lng0;
|
| 998 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, cel, phi, theta, prj,
|
| 999 |
|
|
imgcrd, lin, pixcrd))) {
|
| 1000 |
|
|
return err;
|
| 1001 |
|
|
}
|
| 1002 |
|
|
d0 = pixcrd[mixpix] - pixmix;
|
| 1003 |
|
|
|
| 1004 |
|
|
dabs = fabs(d0);
|
| 1005 |
|
|
if (dabs < tol) return 0;
|
| 1006 |
|
|
|
| 1007 |
|
|
lng1 = span[1];
|
| 1008 |
|
|
world[wcs->lng] = lng1;
|
| 1009 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, cel, phi, theta, prj,
|
| 1010 |
|
|
imgcrd, lin, pixcrd))) {
|
| 1011 |
|
|
return err;
|
| 1012 |
|
|
}
|
| 1013 |
|
|
d1 = pixcrd[mixpix] - pixmix;
|
| 1014 |
|
|
|
| 1015 |
|
|
dabs = fabs(d1);
|
| 1016 |
|
|
if (dabs < tol) return 0;
|
| 1017 |
|
|
lmin = lng1;
|
| 1018 |
|
|
dmin = dabs;
|
| 1019 |
|
|
|
| 1020 |
|
|
/* Check for a crossing point. */
|
| 1021 |
|
|
if (wcs_signbit(d0) != wcs_signbit(d1)) {
|
| 1022 |
|
|
crossed = 1;
|
| 1023 |
|
|
dx = d1;
|
| 1024 |
|
|
} else {
|
| 1025 |
|
|
crossed = 0;
|
| 1026 |
|
|
lng0 = span[1];
|
| 1027 |
|
|
}
|
| 1028 |
|
|
|
| 1029 |
|
|
for (retry = 0; retry < 4; retry++) {
|
| 1030 |
|
|
/* Refine the solution interval. */
|
| 1031 |
|
|
while (lng0 > span[0]) {
|
| 1032 |
|
|
lng0 -= step;
|
| 1033 |
|
|
if (lng0 < span[0]) lng0 = span[0];
|
| 1034 |
|
|
world[wcs->lng] = lng0;
|
| 1035 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, cel, phi, theta,
|
| 1036 |
|
|
prj, imgcrd, lin, pixcrd))) {
|
| 1037 |
|
|
return err;
|
| 1038 |
|
|
}
|
| 1039 |
|
|
d0 = pixcrd[mixpix] - pixmix;
|
| 1040 |
|
|
|
| 1041 |
|
|
/* Check for a solution. */
|
| 1042 |
|
|
dabs = fabs(d0);
|
| 1043 |
|
|
if (dabs < tol) return 0;
|
| 1044 |
|
|
|
| 1045 |
|
|
/* Record the point of closest approach. */
|
| 1046 |
|
|
if (dabs < dmin) {
|
| 1047 |
|
|
lmin = lng0;
|
| 1048 |
|
|
dmin = dabs;
|
| 1049 |
|
|
}
|
| 1050 |
|
|
|
| 1051 |
|
|
/* Check for a crossing point. */
|
| 1052 |
|
|
if (wcs_signbit(d0) != wcs_signbit(d1)) {
|
| 1053 |
|
|
crossed = 2;
|
| 1054 |
|
|
dx = d0;
|
| 1055 |
|
|
break;
|
| 1056 |
|
|
}
|
| 1057 |
|
|
|
| 1058 |
|
|
/* Advance to the next subinterval. */
|
| 1059 |
|
|
lng1 = lng0;
|
| 1060 |
|
|
d1 = d0;
|
| 1061 |
|
|
}
|
| 1062 |
|
|
|
| 1063 |
|
|
if (crossed) {
|
| 1064 |
|
|
/* A crossing point was found. */
|
| 1065 |
|
|
for (iter = 0; iter < niter; iter++) {
|
| 1066 |
|
|
/* Use regula falsi division of the interval. */
|
| 1067 |
|
|
lambda = d0/(d0-d1);
|
| 1068 |
|
|
if (lambda < 0.1) {
|
| 1069 |
|
|
lambda = 0.1;
|
| 1070 |
|
|
} else if (lambda > 0.9) {
|
| 1071 |
|
|
lambda = 0.9;
|
| 1072 |
|
|
}
|
| 1073 |
|
|
|
| 1074 |
|
|
lng = lng0 + lambda*(lng1 - lng0);
|
| 1075 |
|
|
world[wcs->lng] = lng;
|
| 1076 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, cel, phi, theta,
|
| 1077 |
|
|
prj, imgcrd, lin, pixcrd))) {
|
| 1078 |
|
|
return err;
|
| 1079 |
|
|
}
|
| 1080 |
|
|
d = pixcrd[mixpix] - pixmix;
|
| 1081 |
|
|
|
| 1082 |
|
|
/* Check for a solution. */
|
| 1083 |
|
|
dabs = fabs(d);
|
| 1084 |
|
|
if (dabs < tol) return 0;
|
| 1085 |
|
|
|
| 1086 |
|
|
/* Record the point of closest approach. */
|
| 1087 |
|
|
if (dabs < dmin) {
|
| 1088 |
|
|
lmin = lng;
|
| 1089 |
|
|
dmin = dabs;
|
| 1090 |
|
|
}
|
| 1091 |
|
|
|
| 1092 |
|
|
if (wcs_signbit(d0) == wcs_signbit(d)) {
|
| 1093 |
|
|
lng0 = lng;
|
| 1094 |
|
|
d0 = d;
|
| 1095 |
|
|
} else {
|
| 1096 |
|
|
lng1 = lng;
|
| 1097 |
|
|
d1 = d;
|
| 1098 |
|
|
}
|
| 1099 |
|
|
}
|
| 1100 |
|
|
|
| 1101 |
|
|
/* No convergence, must have been a discontinuity. */
|
| 1102 |
|
|
if (crossed == 1) lng0 = span[1];
|
| 1103 |
|
|
lng1 = lng0;
|
| 1104 |
|
|
d1 = dx;
|
| 1105 |
|
|
crossed = 0;
|
| 1106 |
|
|
|
| 1107 |
|
|
} else {
|
| 1108 |
|
|
/* No crossing point; look for a tangent point. */
|
| 1109 |
|
|
if (lmin == span[0]) break;
|
| 1110 |
|
|
if (lmin == span[1]) break;
|
| 1111 |
|
|
|
| 1112 |
|
|
lng = lmin;
|
| 1113 |
|
|
lng0 = lng - step;
|
| 1114 |
|
|
if (lng0 < span[0]) lng0 = span[0];
|
| 1115 |
|
|
lng1 = lng + step;
|
| 1116 |
|
|
if (lng1 > span[1]) lng1 = span[1];
|
| 1117 |
|
|
|
| 1118 |
|
|
world[wcs->lng] = lng0;
|
| 1119 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, cel, phi, theta,
|
| 1120 |
|
|
prj, imgcrd, lin, pixcrd))) {
|
| 1121 |
|
|
return err;
|
| 1122 |
|
|
}
|
| 1123 |
|
|
d0 = fabs(pixcrd[mixpix] - pixmix);
|
| 1124 |
|
|
|
| 1125 |
|
|
d = dmin;
|
| 1126 |
|
|
|
| 1127 |
|
|
world[wcs->lng] = lng1;
|
| 1128 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, cel, phi, theta,
|
| 1129 |
|
|
prj, imgcrd, lin, pixcrd))) {
|
| 1130 |
|
|
return err;
|
| 1131 |
|
|
}
|
| 1132 |
|
|
d1 = fabs(pixcrd[mixpix] - pixmix);
|
| 1133 |
|
|
|
| 1134 |
|
|
for (iter = 0; iter < niter; iter++) {
|
| 1135 |
|
|
lng0m = (lng0 + lng)/2.0;
|
| 1136 |
|
|
world[wcs->lng] = lng0m;
|
| 1137 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, cel, phi, theta,
|
| 1138 |
|
|
prj, imgcrd, lin, pixcrd))) {
|
| 1139 |
|
|
return err;
|
| 1140 |
|
|
}
|
| 1141 |
|
|
d0m = fabs(pixcrd[mixpix] - pixmix);
|
| 1142 |
|
|
|
| 1143 |
|
|
if (d0m < tol) return 0;
|
| 1144 |
|
|
|
| 1145 |
|
|
lng1m = (lng1 + lng)/2.0;
|
| 1146 |
|
|
world[wcs->lng] = lng1m;
|
| 1147 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, cel, phi, theta,
|
| 1148 |
|
|
prj, imgcrd, lin, pixcrd))) {
|
| 1149 |
|
|
return err;
|
| 1150 |
|
|
}
|
| 1151 |
|
|
d1m = fabs(pixcrd[mixpix] - pixmix);
|
| 1152 |
|
|
|
| 1153 |
|
|
if (d1m < tol) return 0;
|
| 1154 |
|
|
|
| 1155 |
|
|
if (d0m < d && d0m <= d1m) {
|
| 1156 |
|
|
lng1 = lng;
|
| 1157 |
|
|
d1 = d;
|
| 1158 |
|
|
lng = lng0m;
|
| 1159 |
|
|
d = d0m;
|
| 1160 |
|
|
} else if (d1m < d) {
|
| 1161 |
|
|
lng0 = lng;
|
| 1162 |
|
|
d0 = d;
|
| 1163 |
|
|
lng = lng1m;
|
| 1164 |
|
|
d = d1m;
|
| 1165 |
|
|
} else {
|
| 1166 |
|
|
lng0 = lng0m;
|
| 1167 |
|
|
d0 = d0m;
|
| 1168 |
|
|
lng1 = lng1m;
|
| 1169 |
|
|
d1 = d1m;
|
| 1170 |
|
|
}
|
| 1171 |
|
|
}
|
| 1172 |
|
|
}
|
| 1173 |
|
|
}
|
| 1174 |
|
|
}
|
| 1175 |
|
|
}
|
| 1176 |
|
|
|
| 1177 |
|
|
|
| 1178 |
|
|
/* Set cel0 to the unity transformation. */
|
| 1179 |
|
|
cel0.flag = CELSET;
|
| 1180 |
|
|
cel0.ref[0] = cel->ref[0];
|
| 1181 |
|
|
cel0.ref[1] = cel->ref[1];
|
| 1182 |
|
|
cel0.ref[2] = cel->ref[2];
|
| 1183 |
|
|
cel0.ref[3] = cel->ref[3];
|
| 1184 |
|
|
cel0.euler[0] = -90.0;
|
| 1185 |
|
|
cel0.euler[1] = 0.0;
|
| 1186 |
|
|
cel0.euler[2] = 90.0;
|
| 1187 |
|
|
cel0.euler[3] = 1.0;
|
| 1188 |
|
|
cel0.euler[4] = 0.0;
|
| 1189 |
|
|
cel0.prjfwd = cel->prjfwd;
|
| 1190 |
|
|
cel0.prjrev = cel->prjrev;
|
| 1191 |
|
|
|
| 1192 |
|
|
/* No convergence, check for aberrant behaviour at a native pole. */
|
| 1193 |
|
|
*theta = -90.0;
|
| 1194 |
|
|
for (j = 1; j <= 2; j++) {
|
| 1195 |
|
|
/* Could the celestial coordinate element map to a native pole? */
|
| 1196 |
|
|
*theta = -*theta;
|
| 1197 |
|
|
err = sphrev(0.0, *theta, cel->euler, &lng, &lat);
|
| 1198 |
|
|
|
| 1199 |
|
|
if (mixcel == 1) {
|
| 1200 |
|
|
if (fabs(fmod(world[wcs->lng]-lng,360.0)) > tol) continue;
|
| 1201 |
|
|
if (lat < span[0]) continue;
|
| 1202 |
|
|
if (lat > span[1]) continue;
|
| 1203 |
|
|
world[wcs->lat] = lat;
|
| 1204 |
|
|
} else {
|
| 1205 |
|
|
if (fabs(world[wcs->lat]-lat) > tol) continue;
|
| 1206 |
|
|
if (lng < span[0]) lng += 360.0;
|
| 1207 |
|
|
if (lng > span[1]) lng -= 360.0;
|
| 1208 |
|
|
if (lng < span[0]) continue;
|
| 1209 |
|
|
if (lng > span[1]) continue;
|
| 1210 |
|
|
world[wcs->lng] = lng;
|
| 1211 |
|
|
}
|
| 1212 |
|
|
|
| 1213 |
|
|
/* Is there a solution for the given pixel coordinate element? */
|
| 1214 |
|
|
lng = world[wcs->lng];
|
| 1215 |
|
|
lat = world[wcs->lat];
|
| 1216 |
|
|
|
| 1217 |
|
|
/* Feed native coordinates to wcsfwd() with cel0 set to unity. */
|
| 1218 |
|
|
world[wcs->lng] = -180.0;
|
| 1219 |
|
|
world[wcs->lat] = *theta;
|
| 1220 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, &cel0, phi, theta, prj,
|
| 1221 |
|
|
imgcrd, lin, pixcrd))) {
|
| 1222 |
|
|
return err;
|
| 1223 |
|
|
}
|
| 1224 |
|
|
d0 = pixcrd[mixpix] - pixmix;
|
| 1225 |
|
|
|
| 1226 |
|
|
/* Check for a solution. */
|
| 1227 |
|
|
if (fabs(d0) < tol) {
|
| 1228 |
|
|
/* Recall saved world coordinates. */
|
| 1229 |
|
|
world[wcs->lng] = lng;
|
| 1230 |
|
|
world[wcs->lat] = lat;
|
| 1231 |
|
|
return 0;
|
| 1232 |
|
|
}
|
| 1233 |
|
|
|
| 1234 |
|
|
/* Search for a crossing interval. */
|
| 1235 |
|
|
phi0 = -180.0;
|
| 1236 |
|
|
for (k = -179; k <= 180; k++) {
|
| 1237 |
|
|
phi1 = (float) k;
|
| 1238 |
|
|
world[wcs->lng] = phi1;
|
| 1239 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, &cel0, phi, theta, prj,
|
| 1240 |
|
|
imgcrd, lin, pixcrd))) {
|
| 1241 |
|
|
return err;
|
| 1242 |
|
|
}
|
| 1243 |
|
|
d1 = pixcrd[mixpix] - pixmix;
|
| 1244 |
|
|
|
| 1245 |
|
|
/* Check for a solution. */
|
| 1246 |
|
|
dabs = fabs(d1);
|
| 1247 |
|
|
if (dabs < tol) {
|
| 1248 |
|
|
/* Recall saved world coordinates. */
|
| 1249 |
|
|
world[wcs->lng] = lng;
|
| 1250 |
|
|
world[wcs->lat] = lat;
|
| 1251 |
|
|
return 0;
|
| 1252 |
|
|
}
|
| 1253 |
|
|
|
| 1254 |
|
|
/* Is it a crossing interval? */
|
| 1255 |
|
|
if (wcs_signbit(d0) != wcs_signbit(d1)) break;
|
| 1256 |
|
|
|
| 1257 |
|
|
phi0 = phi1;
|
| 1258 |
|
|
d0 = d1;
|
| 1259 |
|
|
}
|
| 1260 |
|
|
|
| 1261 |
|
|
for (iter = 1; iter <= niter; iter++) {
|
| 1262 |
|
|
/* Use regula falsi division of the interval. */
|
| 1263 |
|
|
lambda = d0/(d0-d1);
|
| 1264 |
|
|
if (lambda < 0.1) {
|
| 1265 |
|
|
lambda = 0.1;
|
| 1266 |
|
|
} else if (lambda > 0.9) {
|
| 1267 |
|
|
lambda = 0.9;
|
| 1268 |
|
|
}
|
| 1269 |
|
|
|
| 1270 |
|
|
world[wcs->lng] = phi0 + lambda*(phi1 - phi0);
|
| 1271 |
|
|
if ((err = wcsfwd(ctype, wcs, world, crval, &cel0, phi, theta, prj,
|
| 1272 |
|
|
imgcrd, lin, pixcrd))) {
|
| 1273 |
|
|
return err;
|
| 1274 |
|
|
}
|
| 1275 |
|
|
d = pixcrd[mixpix] - pixmix;
|
| 1276 |
|
|
|
| 1277 |
|
|
/* Check for a solution. */
|
| 1278 |
|
|
dabs = fabs(d);
|
| 1279 |
|
|
if (dabs < tol) {
|
| 1280 |
|
|
/* Recall saved world coordinates. */
|
| 1281 |
|
|
world[wcs->lng] = lng;
|
| 1282 |
|
|
world[wcs->lat] = lat;
|
| 1283 |
|
|
return 0;
|
| 1284 |
|
|
}
|
| 1285 |
|
|
|
| 1286 |
|
|
if (wcs_signbit(d0) == wcs_signbit(d)) {
|
| 1287 |
|
|
phi0 = world[wcs->lng];
|
| 1288 |
|
|
d0 = d;
|
| 1289 |
|
|
} else {
|
| 1290 |
|
|
phi1 = world[wcs->lng];
|
| 1291 |
|
|
d1 = d;
|
| 1292 |
|
|
}
|
| 1293 |
|
|
}
|
| 1294 |
|
|
}
|
| 1295 |
|
|
|
| 1296 |
|
|
|
| 1297 |
|
|
/* No solution. */
|
| 1298 |
|
|
return 5;
|
| 1299 |
|
|
|
| 1300 |
|
|
}
|
