00001 /*============================================================================ 00002 00003 WCSLIB 4.15 - an implementation of the FITS WCS standard. 00004 Copyright (C) 1995-2012, Mark Calabretta 00005 00006 This file is part of WCSLIB. 00007 00008 WCSLIB is free software: you can redistribute it and/or modify it under the 00009 terms of the GNU Lesser General Public License as published by the Free 00010 Software Foundation, either version 3 of the License, or (at your option) 00011 any later version. 00012 00013 WCSLIB is distributed in the hope that it will be useful, but WITHOUT ANY 00014 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 00015 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for 00016 more details. 00017 00018 You should have received a copy of the GNU Lesser General Public License 00019 along with WCSLIB. If not, see http://www.gnu.org/licenses. 00020 00021 Direct correspondence concerning WCSLIB to mark@calabretta.id.au 00022 00023 Author: Mark Calabretta, Australia Telescope National Facility, CSIRO. 00024 http://www.atnf.csiro.au/people/Mark.Calabretta 00025 $Id: spx.h,v 4.15 2012/09/26 14:26:05 cal103 Exp $ 00026 *============================================================================= 00027 * 00028 * WCSLIB 4.15 - C routines that implement the spectral coordinate systems 00029 * recognized by the FITS World Coordinate System (WCS) standard. Refer to 00030 * 00031 * "Representations of world coordinates in FITS", 00032 * Greisen, E.W., & Calabretta, M.R. 2002, A&A, 395, 1061 (Paper I) 00033 * 00034 * "Representations of spectral coordinates in FITS", 00035 * Greisen, E.W., Calabretta, M.R., Valdes, F.G., & Allen, S.L. 00036 * 2006, A&A, 446, 747 (Paper III) 00037 * 00038 * Refer to the README file provided with WCSLIB for an overview of the 00039 * library. 00040 * 00041 * 00042 * Summary of the spx routines 00043 * --------------------------- 00044 * specx() is a scalar routine that, given one spectral variable (e.g. 00045 * frequency), computes all the others (e.g. wavelength, velocity, etc.) plus 00046 * the required derivatives of each with respect to the others. The results 00047 * are returned in the spxprm struct. 00048 * 00049 * The remaining routines are all vector conversions from one spectral 00050 * variable to another. The API of these functions only differ in whether the 00051 * rest frequency or wavelength need be supplied. 00052 * 00053 * Non-linear: 00054 * - freqwave() frequency -> vacuum wavelength 00055 * - wavefreq() vacuum wavelength -> frequency 00056 * 00057 * - freqawav() frequency -> air wavelength 00058 * - awavfreq() air wavelength -> frequency 00059 * 00060 * - freqvelo() frequency -> relativistic velocity 00061 * - velofreq() relativistic velocity -> frequency 00062 * 00063 * - waveawav() vacuum wavelength -> air wavelength 00064 * - awavwave() air wavelength -> vacuum wavelength 00065 * 00066 * - wavevelo() vacuum wavelength -> relativistic velocity 00067 * - velowave() relativistic velocity -> vacuum wavelength 00068 * 00069 * - awavvelo() air wavelength -> relativistic velocity 00070 * - veloawav() relativistic velocity -> air wavelength 00071 * 00072 * Linear: 00073 * - freqafrq() frequency -> angular frequency 00074 * - afrqfreq() angular frequency -> frequency 00075 * 00076 * - freqener() frequency -> energy 00077 * - enerfreq() energy -> frequency 00078 * 00079 * - freqwavn() frequency -> wave number 00080 * - wavnfreq() wave number -> frequency 00081 * 00082 * - freqvrad() frequency -> radio velocity 00083 * - vradfreq() radio velocity -> frequency 00084 * 00085 * - wavevopt() vacuum wavelength -> optical velocity 00086 * - voptwave() optical velocity -> vacuum wavelength 00087 * 00088 * - wavezopt() vacuum wavelength -> redshift 00089 * - zoptwave() redshift -> vacuum wavelength 00090 * 00091 * - velobeta() relativistic velocity -> beta (= v/c) 00092 * - betavelo() beta (= v/c) -> relativistic velocity 00093 * 00094 * These are the workhorse routines, to be used for fast transformations. 00095 * Conversions may be done "in place" by calling the routine with the output 00096 * vector set to the input. 00097 * 00098 * Argument checking: 00099 * ------------------ 00100 * The input spectral values are only checked for values that would result 00101 * in floating point exceptions. In particular, negative frequencies and 00102 * wavelengths are allowed, as are velocities greater than the speed of 00103 * light. The same is true for the spectral parameters - rest frequency and 00104 * wavelength. 00105 * 00106 * Accuracy: 00107 * --------- 00108 * No warranty is given for the accuracy of these routines (refer to the 00109 * copyright notice); intending users must satisfy for themselves their 00110 * adequacy for the intended purpose. However, closure effectively to within 00111 * double precision rounding error was demonstrated by test routine tspec.c 00112 * which accompanies this software. 00113 * 00114 * 00115 * specx() - Spectral cross conversions (scalar) 00116 * --------------------------------------------- 00117 * Given one spectral variable specx() computes all the others, plus the 00118 * required derivatives of each with respect to the others. 00119 * 00120 * Given: 00121 * type const char* 00122 * The type of spectral variable given by spec, FREQ, 00123 * AFRQ, ENER, WAVN, VRAD, WAVE, VOPT, ZOPT, AWAV, VELO, 00124 * or BETA (case sensitive). 00125 * 00126 * spec double The spectral variable given, in SI units. 00127 * 00128 * restfrq, 00129 * restwav double Rest frequency [Hz] or rest wavelength in vacuo [m], 00130 * only one of which need be given. The other should be 00131 * set to zero. If both are zero, only a subset of the 00132 * spectral variables can be computed, the remainder are 00133 * set to zero. Specifically, given one of FREQ, AFRQ, 00134 * ENER, WAVN, WAVE, or AWAV the others can be computed 00135 * without knowledge of the rest frequency. Likewise, 00136 * VRAD, VOPT, ZOPT, VELO, and BETA. 00137 * 00138 * Given and returned: 00139 * specs struct spxprm* 00140 * Data structure containing all spectral variables and 00141 * their derivatives, in SI units. 00142 * 00143 * Function return value: 00144 * int Status return value: 00145 * 0: Success. 00146 * 1: Null spxprm pointer passed. 00147 * 2: Invalid spectral parameters. 00148 * 3: Invalid spectral variable. 00149 * 00150 * For returns > 1, a detailed error message is set in 00151 * spxprm::err if enabled, see wcserr_enable(). 00152 * 00153 * freqafrq(), afrqfreq(), freqener(), enerfreq(), freqwavn(), wavnfreq(), 00154 * freqwave(), wavefreq(), freqawav(), awavfreq(), waveawav(), awavwave(), 00155 * velobeta(), and betavelo() implement vector conversions between wave-like 00156 * or velocity-like spectral types (i.e. conversions that do not need the rest 00157 * frequency or wavelength). They all have the same API. 00158 * 00159 * 00160 * freqafrq() - Convert frequency to angular frequency (vector) 00161 * ------------------------------------------------------------ 00162 * freqafrq() converts frequency to angular frequency. 00163 * 00164 * Given: 00165 * param double Ignored. 00166 * 00167 * nspec int Vector length. 00168 * 00169 * instep, 00170 * outstep int Vector strides. 00171 * 00172 * inspec const double[] 00173 * Input spectral variables, in SI units. 00174 * 00175 * Returned: 00176 * outspec double[] Output spectral variables, in SI units. 00177 * 00178 * stat int[] Status return value for each vector element: 00179 * 0: Success. 00180 * 1: Invalid value of inspec. 00181 * 00182 * Function return value: 00183 * int Status return value: 00184 * 0: Success. 00185 * 2: Invalid spectral parameters. 00186 * 4: One or more of the inspec coordinates were 00187 * invalid, as indicated by the stat vector. 00188 * 00189 * 00190 * freqvelo(), velofreq(), freqvrad(), and vradfreq() implement vector 00191 * conversions between frequency and velocity spectral types. They all have 00192 * the same API. 00193 * 00194 * 00195 * freqvelo() - Convert frequency to relativistic velocity (vector) 00196 * ---------------------------------------------------------------- 00197 * freqvelo() converts frequency to relativistic velocity. 00198 * 00199 * Given: 00200 * param double Rest frequency [Hz]. 00201 * 00202 * nspec int Vector length. 00203 * 00204 * instep, 00205 * outstep int Vector strides. 00206 * 00207 * inspec const double[] 00208 * Input spectral variables, in SI units. 00209 * 00210 * Returned: 00211 * outspec double[] Output spectral variables, in SI units. 00212 * 00213 * stat int[] Status return value for each vector element: 00214 * 0: Success. 00215 * 1: Invalid value of inspec. 00216 * 00217 * Function return value: 00218 * int Status return value: 00219 * 0: Success. 00220 * 2: Invalid spectral parameters. 00221 * 4: One or more of the inspec coordinates were 00222 * invalid, as indicated by the stat vector. 00223 * 00224 * 00225 * wavevelo(), velowave(), awavvelo(), veloawav(), wavevopt(), voptwave(), 00226 * wavezopt(), and zoptwave() implement vector conversions between wavelength 00227 * and velocity spectral types. They all have the same API. 00228 * 00229 * 00230 * wavevelo() - Conversions between wavelength and velocity types (vector) 00231 * ----------------------------------------------------------------------- 00232 * wavevelo() converts vacuum wavelength to relativistic velocity. 00233 * 00234 * Given: 00235 * param double Rest wavelength in vacuo [m]. 00236 * 00237 * nspec int Vector length. 00238 * 00239 * instep, 00240 * outstep int Vector strides. 00241 * 00242 * inspec const double[] 00243 * Input spectral variables, in SI units. 00244 * 00245 * Returned: 00246 * outspec double[] Output spectral variables, in SI units. 00247 * 00248 * stat int[] Status return value for each vector element: 00249 * 0: Success. 00250 * 1: Invalid value of inspec. 00251 * 00252 * Function return value: 00253 * int Status return value: 00254 * 0: Success. 00255 * 2: Invalid spectral parameters. 00256 * 4: One or more of the inspec coordinates were 00257 * invalid, as indicated by the stat vector. 00258 * 00259 * 00260 * spxprm struct - Spectral variables and their derivatives 00261 * -------------------------------------------------------- 00262 * The spxprm struct contains the value of all spectral variables and their 00263 * derivatives. It is used solely by specx() which constructs it from 00264 * information provided via its function arguments. 00265 * 00266 * This struct should be considered read-only, no members need ever be set nor 00267 * should ever be modified by the user. 00268 * 00269 * double restfrq 00270 * (Returned) Rest frequency [Hz]. 00271 * 00272 * double restwav 00273 * (Returned) Rest wavelength [m]. 00274 * 00275 * int wavetype 00276 * (Returned) True if wave types have been computed, and ... 00277 * 00278 * int velotype 00279 * (Returned) ... true if velocity types have been computed; types are 00280 * defined below. 00281 * 00282 * If one or other of spxprm::restfrq and spxprm::restwav is given 00283 * (non-zero) then all spectral variables may be computed. If both are 00284 * given, restfrq is used. If restfrq and restwav are both zero, only wave 00285 * characteristic xor velocity type spectral variables may be computed 00286 * depending on the variable given. These flags indicate what is 00287 * available. 00288 * 00289 * double freq 00290 * (Returned) Frequency [Hz] (wavetype). 00291 * 00292 * double afrq 00293 * (Returned) Angular frequency [rad/s] (wavetype). 00294 * 00295 * double ener 00296 * (Returned) Photon energy [J] (wavetype). 00297 * 00298 * double wavn 00299 * (Returned) Wave number [/m] (wavetype). 00300 * 00301 * double vrad 00302 * (Returned) Radio velocity [m/s] (velotype). 00303 * 00304 * double wave 00305 * (Returned) Vacuum wavelength [m] (wavetype). 00306 * 00307 * double vopt 00308 * (Returned) Optical velocity [m/s] (velotype). 00309 * 00310 * double zopt 00311 * (Returned) Redshift [dimensionless] (velotype). 00312 * 00313 * double awav 00314 * (Returned) Air wavelength [m] (wavetype). 00315 * 00316 * double velo 00317 * (Returned) Relativistic velocity [m/s] (velotype). 00318 * 00319 * double beta 00320 * (Returned) Relativistic beta [dimensionless] (velotype). 00321 * 00322 * double dfreqafrq 00323 * (Returned) Derivative of frequency with respect to angular frequency 00324 * [/rad] (constant, = 1 / 2*pi), and ... 00325 * double dafrqfreq 00326 * (Returned) ... vice versa [rad] (constant, = 2*pi, always available). 00327 * 00328 * double dfreqener 00329 * (Returned) Derivative of frequency with respect to photon energy 00330 * [/J/s] (constant, = 1/h), and ... 00331 * double denerfreq 00332 * (Returned) ... vice versa [Js] (constant, = h, Planck's constant, 00333 * always available). 00334 * 00335 * double dfreqwavn 00336 * (Returned) Derivative of frequency with respect to wave number [m/s] 00337 * (constant, = c, the speed of light in vacuuo), and ... 00338 * double dwavnfreq 00339 * (Returned) ... vice versa [s/m] (constant, = 1/c, always available). 00340 * 00341 * double dfreqvrad 00342 * (Returned) Derivative of frequency with respect to radio velocity [/m], 00343 * and ... 00344 * double dvradfreq 00345 * (Returned) ... vice versa [m] (wavetype && velotype). 00346 * 00347 * double dfreqwave 00348 * (Returned) Derivative of frequency with respect to vacuum wavelength 00349 * [/m/s], and ... 00350 * double dwavefreq 00351 * (Returned) ... vice versa [m s] (wavetype). 00352 * 00353 * double dfreqawav 00354 * (Returned) Derivative of frequency with respect to air wavelength, 00355 * [/m/s], and ... 00356 * double dawavfreq 00357 * (Returned) ... vice versa [m s] (wavetype). 00358 * 00359 * double dfreqvelo 00360 * (Returned) Derivative of frequency with respect to relativistic 00361 * velocity [/m], and ... 00362 * double dvelofreq 00363 * (Returned) ... vice versa [m] (wavetype && velotype). 00364 * 00365 * double dwavevopt 00366 * (Returned) Derivative of vacuum wavelength with respect to optical 00367 * velocity [s], and ... 00368 * double dvoptwave 00369 * (Returned) ... vice versa [/s] (wavetype && velotype). 00370 * 00371 * double dwavezopt 00372 * (Returned) Derivative of vacuum wavelength with respect to redshift [m], 00373 * and ... 00374 * double dzoptwave 00375 * (Returned) ... vice versa [/m] (wavetype && velotype). 00376 * 00377 * double dwaveawav 00378 * (Returned) Derivative of vacuum wavelength with respect to air 00379 * wavelength [dimensionless], and ... 00380 * double dawavwave 00381 * (Returned) ... vice versa [dimensionless] (wavetype). 00382 * 00383 * double dwavevelo 00384 * (Returned) Derivative of vacuum wavelength with respect to relativistic 00385 * velocity [s], and ... 00386 * double dvelowave 00387 * (Returned) ... vice versa [/s] (wavetype && velotype). 00388 * 00389 * double dawavvelo 00390 * (Returned) Derivative of air wavelength with respect to relativistic 00391 * velocity [s], and ... 00392 * double dveloawav 00393 * (Returned) ... vice versa [/s] (wavetype && velotype). 00394 * 00395 * double dvelobeta 00396 * (Returned) Derivative of relativistic velocity with respect to 00397 * relativistic beta [m/s] (constant, = c, the speed of light in vacuu0), 00398 * and ... 00399 * double dbetavelo 00400 * (Returned) ... vice versa [s/m] (constant, = 1/c, always available). 00401 * 00402 * struct wcserr *err 00403 * (Returned) If enabled, when an error status is returned this struct 00404 * contains detailed information about the error, see wcserr_enable(). 00405 * 00406 * void *padding 00407 * (An unused variable inserted for alignment purposes only.) 00408 * 00409 * Global variable: const char *spx_errmsg[] - Status return messages 00410 * ------------------------------------------------------------------ 00411 * Error messages to match the status value returned from each function. 00412 * 00413 *===========================================================================*/ 00414 00415 #ifndef WCSLIB_SPEC 00416 #define WCSLIB_SPEC 00417 00418 #ifdef __cplusplus 00419 extern "C" { 00420 #endif 00421 00422 #include "wcserr.h" 00423 00424 extern const char *spx_errmsg[]; 00425 00426 enum spx_errmsg { 00427 SPXERR_SUCCESS = 0, /* Success. */ 00428 SPXERR_NULL_POINTER = 1, /* Null spxprm pointer passed. */ 00429 SPXERR_BAD_SPEC_PARAMS = 2, /* Invalid spectral parameters. */ 00430 SPXERR_BAD_SPEC_VAR = 3, /* Invalid spectral variable. */ 00431 SPXERR_BAD_INSPEC_COORD = 4 /* One or more of the inspec coordinates were 00432 invalid. */ 00433 }; 00434 00435 struct spxprm { 00436 double restfrq, restwav; /* Rest frequency [Hz] and wavelength [m]. */ 00437 00438 int wavetype, velotype; /* True if wave/velocity types have been */ 00439 /* computed; types are defined below. */ 00440 00441 /* Spectral variables computed by specx(). */ 00442 /*------------------------------------------------------------------------*/ 00443 double freq, /* wavetype: Frequency [Hz]. */ 00444 afrq, /* wavetype: Angular frequency [rad/s]. */ 00445 ener, /* wavetype: Photon energy [J]. */ 00446 wavn, /* wavetype: Wave number [/m]. */ 00447 vrad, /* velotype: Radio velocity [m/s]. */ 00448 wave, /* wavetype: Vacuum wavelength [m]. */ 00449 vopt, /* velotype: Optical velocity [m/s]. */ 00450 zopt, /* velotype: Redshift. */ 00451 awav, /* wavetype: Air wavelength [m]. */ 00452 velo, /* velotype: Relativistic velocity [m/s]. */ 00453 beta; /* velotype: Relativistic beta. */ 00454 00455 /* Derivatives of spectral variables computed by specx(). */ 00456 /*------------------------------------------------------------------------*/ 00457 double dfreqafrq, dafrqfreq, /* Constant, always available. */ 00458 dfreqener, denerfreq, /* Constant, always available. */ 00459 dfreqwavn, dwavnfreq, /* Constant, always available. */ 00460 dfreqvrad, dvradfreq, /* wavetype && velotype. */ 00461 dfreqwave, dwavefreq, /* wavetype. */ 00462 dfreqawav, dawavfreq, /* wavetype. */ 00463 dfreqvelo, dvelofreq, /* wavetype && velotype. */ 00464 dwavevopt, dvoptwave, /* wavetype && velotype. */ 00465 dwavezopt, dzoptwave, /* wavetype && velotype. */ 00466 dwaveawav, dawavwave, /* wavetype. */ 00467 dwavevelo, dvelowave, /* wavetype && velotype. */ 00468 dawavvelo, dveloawav, /* wavetype && velotype. */ 00469 dvelobeta, dbetavelo; /* Constant, always available. */ 00470 00471 /* Error handling */ 00472 /*------------------------------------------------------------------------*/ 00473 struct wcserr *err; 00474 00475 /* Private */ 00476 /*------------------------------------------------------------------------*/ 00477 void *padding; /* (Dummy inserted for alignment purposes.) */ 00478 }; 00479 00480 /* Size of the spxprm struct in int units, used by the Fortran wrappers. */ 00481 #define SPXLEN (sizeof(struct spxprm)/sizeof(int)) 00482 00483 00484 int specx(const char *type, double spec, double restfrq, double restwav, 00485 struct spxprm *specs); 00486 00487 00488 /* For use in declaring function prototypes, e.g. in spcprm. */ 00489 #define SPX_ARGS double param, int nspec, int instep, int outstep, \ 00490 const double inspec[], double outspec[], int stat[] 00491 00492 int freqafrq(SPX_ARGS); 00493 int afrqfreq(SPX_ARGS); 00494 00495 int freqener(SPX_ARGS); 00496 int enerfreq(SPX_ARGS); 00497 00498 int freqwavn(SPX_ARGS); 00499 int wavnfreq(SPX_ARGS); 00500 00501 int freqwave(SPX_ARGS); 00502 int wavefreq(SPX_ARGS); 00503 00504 int freqawav(SPX_ARGS); 00505 int awavfreq(SPX_ARGS); 00506 00507 int waveawav(SPX_ARGS); 00508 int awavwave(SPX_ARGS); 00509 00510 int velobeta(SPX_ARGS); 00511 int betavelo(SPX_ARGS); 00512 00513 00514 int freqvelo(SPX_ARGS); 00515 int velofreq(SPX_ARGS); 00516 00517 int freqvrad(SPX_ARGS); 00518 int vradfreq(SPX_ARGS); 00519 00520 00521 int wavevelo(SPX_ARGS); 00522 int velowave(SPX_ARGS); 00523 00524 int awavvelo(SPX_ARGS); 00525 int veloawav(SPX_ARGS); 00526 00527 int wavevopt(SPX_ARGS); 00528 int voptwave(SPX_ARGS); 00529 00530 int wavezopt(SPX_ARGS); 00531 int zoptwave(SPX_ARGS); 00532 00533 00534 #ifdef __cplusplus 00535 } 00536 #endif 00537 00538 #endif /* WCSLIB_SPEC */