Michael Mayer / gammalib

Commit 866742065bb229897df1ef4b7e9ecd3ddd0cb129

Authored by knodlseder
1 parent 9400e0a3

implement coordinate transformation

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Showing 3 changed files with 161 additions and 7 deletions
include/GSkyDir.hpp
  View file @8667420
... ... @@ -45,11 +45,17 @@ public:
45 45  
46 46 // Methods
47 47 void radec(const double& ra, const double& dec);
  48 + void radec_deg(const double& ra, const double& dec);
48 49 void lb(const double& l, const double& b);
  50 + void lb_deg(const double& l, const double& b);
49 51 double l(void);
  52 + double l_deg(void);
50 53 double b(void);
  54 + double b_deg(void);
51 55 double ra(void);
  56 + double ra_deg(void);
52 57 double dec(void);
  58 + double dec_deg(void);
53 59  
54 60 private:
55 61 // Private methods
... ...
pyext/GSkyDir.i
  View file @8667420
... ... @@ -35,11 +35,17 @@ public:
35 35  
36 36 // Methods
37 37 void radec(const double& ra, const double& dec);
  38 + void radec_deg(const double& ra, const double& dec);
38 39 void lb(const double& l, const double& b);
  40 + void lb_deg(const double& l, const double& b);
39 41 double l(void);
  42 + double l_deg(void);
40 43 double b(void);
  44 + double b_deg(void);
41 45 double ra(void);
  46 + double ra_deg(void);
42 47 double dec(void);
  48 + double dec_deg(void);
43 49 };
44 50  
45 51  
... ...
src/GSkyDir.cpp
  View file @8667420
... ... @@ -13,6 +13,7 @@
13 13 ***************************************************************************/
14 14  
15 15 /* __ Includes ___________________________________________________________ */
  16 +#include <cmath>
16 17 #include "GException.hpp"
17 18 #include "GTools.hpp"
18 19 #include "GSkyDir.hpp"
... ... @@ -27,7 +28,9 @@
27 28  
28 29 /* __ Debug definitions __________________________________________________ */
29 30  
30   -
  31 +/* __ Prototype __________________________________________________________ */
  32 +void euler(const int& type, const double& xin, const double &yin,
  33 + double* xout, double *yout);
31 34  
32 35 /*==========================================================================
33 36 = =
... ... @@ -116,7 +119,7 @@ GSkyDir&amp; GSkyDir::operator= (const GSkyDir&amp; dir)
116 119 ==========================================================================*/
117 120  
118 121 /***********************************************************************//**
119   - * @brief Set equatorial sky direction
  122 + * @brief Set equatorial sky direction (radians)
120 123 *
121 124 * @param[in] ra Right Ascension in radians.
122 125 * @param[in] dec Declination in radians.
... ... @@ -137,7 +140,28 @@ void GSkyDir::radec(const double&amp; ra, const double&amp; dec)
137 140  
138 141  
139 142 /***********************************************************************//**
140   - * @brief Set galactic sky direction
  143 + * @brief Set equatorial sky direction (degrees)
  144 + *
  145 + * @param[in] ra Right Ascension in degrees.
  146 + * @param[in] dec Declination in degrees.
  147 + ***************************************************************************/
  148 +void GSkyDir::radec_deg(const double& ra, const double& dec)
  149 +{
  150 + // Set attributes
  151 + m_has_lb = 0;
  152 + m_has_radec = 1;
  153 +
  154 + // Set direction
  155 + m_ra = ra * deg2rad;
  156 + m_dec = dec * deg2rad;
  157 +
  158 + // Return
  159 + return;
  160 +}
  161 +
  162 +
  163 +/***********************************************************************//**
  164 + * @brief Set galactic sky direction (radians)
141 165 *
142 166 * @param[in] l Galactic longitude in radians.
143 167 * @param[in] b Galactic latitude in radians.
... ... @@ -158,6 +182,27 @@ void GSkyDir::lb(const double&amp; l, const double&amp; b)
158 182  
159 183  
160 184 /***********************************************************************//**
  185 + * @brief Set galactic sky direction (degrees)
  186 + *
  187 + * @param[in] l Galactic longitude in degrees.
  188 + * @param[in] b Galactic latitude in degrees.
  189 + ***************************************************************************/
  190 +void GSkyDir::lb_deg(const double& l, const double& b)
  191 +{
  192 + // Set attributes
  193 + m_has_lb = 1;
  194 + m_has_radec = 0;
  195 +
  196 + // Set direction
  197 + m_l = l * deg2rad;
  198 + m_b = b * deg2rad;
  199 +
  200 + // Return
  201 + return;
  202 +}
  203 +
  204 +
  205 +/***********************************************************************//**
161 206 * @brief Returns galactic longitude in radians
162 207 ***************************************************************************/
163 208 double GSkyDir::l(void)
... ... @@ -172,6 +217,20 @@ double GSkyDir::l(void)
172 217  
173 218  
174 219 /***********************************************************************//**
  220 + * @brief Returns galactic longitude in degrees
  221 + ***************************************************************************/
  222 +double GSkyDir::l_deg(void)
  223 +{
  224 + // If we have no galactic coordinates then get them now
  225 + if (!m_has_lb && m_has_radec)
  226 + equ2gal();
  227 +
  228 + // Return galactic longitude
  229 + return m_l * rad2deg;
  230 +}
  231 +
  232 +
  233 +/***********************************************************************//**
175 234 * @brief Returns galactic latitude in radians
176 235 ***************************************************************************/
177 236 double GSkyDir::b(void)
... ... @@ -186,6 +245,20 @@ double GSkyDir::b(void)
186 245  
187 246  
188 247 /***********************************************************************//**
  248 + * @brief Returns galactic latitude in degrees
  249 + ***************************************************************************/
  250 +double GSkyDir::b_deg(void)
  251 +{
  252 + // If we have no galactic coordinates then get them now
  253 + if (!m_has_lb && m_has_radec)
  254 + equ2gal();
  255 +
  256 + // Return galactic latitude
  257 + return m_b * rad2deg;
  258 +}
  259 +
  260 +
  261 +/***********************************************************************//**
189 262 * @brief Returns Right Ascension in radians
190 263 ***************************************************************************/
191 264 double GSkyDir::ra(void)
... ... @@ -200,6 +273,20 @@ double GSkyDir::ra(void)
200 273  
201 274  
202 275 /***********************************************************************//**
  276 + * @brief Returns Right Ascension in degrees
  277 + ***************************************************************************/
  278 +double GSkyDir::ra_deg(void)
  279 +{
  280 + // If we have no equatorial coordinates then get them now
  281 + if (!m_has_radec && m_has_lb)
  282 + gal2equ();
  283 +
  284 + // Return Right Ascension
  285 + return m_ra * rad2deg;
  286 +}
  287 +
  288 +
  289 +/***********************************************************************//**
203 290 * @brief Returns Declination in radians
204 291 ***************************************************************************/
205 292 double GSkyDir::dec(void)
... ... @@ -213,6 +300,20 @@ double GSkyDir::dec(void)
213 300 }
214 301  
215 302  
  303 +/***********************************************************************//**
  304 + * @brief Returns Declination in degrees
  305 + ***************************************************************************/
  306 +double GSkyDir::dec_deg(void)
  307 +{
  308 + // If we have no equatorial coordinates then get them now
  309 + if (!m_has_radec && m_has_lb)
  310 + gal2equ();
  311 +
  312 + // Return Declination
  313 + return m_dec * rad2deg;
  314 +}
  315 +
  316 +
216 317 /*==========================================================================
217 318 = =
218 319 = GSkyDir private methods =
... ... @@ -273,11 +374,12 @@ void GSkyDir::free_members(void)
273 374  
274 375 /***********************************************************************//**
275 376 * @brief Convert equatorial to galactic coordinates
276   - *
277   - * @todo Needs to be implemented
278 377 ***************************************************************************/
279 378 void GSkyDir::equ2gal(void)
280 379 {
  380 + // Convert from equatorial to galactic
  381 + euler(0, m_ra, m_dec, &m_l, &m_b);
  382 +
281 383 // Return
282 384 return;
283 385 }
... ... @@ -285,11 +387,12 @@ void GSkyDir::equ2gal(void)
285 387  
286 388 /***********************************************************************//**
287 389 * @brief Convert galactic to equatorial coordinates
288   - *
289   - * @todo Needs to be implemented
290 390 ***************************************************************************/
291 391 void GSkyDir::gal2equ(void)
292 392 {
  393 + // Convert from galactic to equatorial
  394 + euler(1, m_l, m_b, &m_ra, &m_dec);
  395 +
293 396 // Return
294 397 return;
295 398 }
... ... @@ -325,3 +428,42 @@ ostream&amp; operator&lt;&lt; (ostream&amp; os, const GSkyDir&amp; dir)
325 428 = Other functions used by GSkyDir =
326 429 = =
327 430 ==========================================================================*/
  431 +
  432 +/***********************************************************************//**
  433 + * @brief General coordinate transformation routine for J2000
  434 + *
  435 + * @param[in] type Conversion type (0=equ2gal, 1=gal2equ)
  436 + * @param[in] xin Input longitude (RA or GLON) in radians.
  437 + * @param[in] yin Input latitude (Dec or GLAT) in radians.
  438 + * @param[out] xout Output longitude in radians.
  439 + * @param[out] yout Output latitude in radians.
  440 + ***************************************************************************/
  441 +void euler(const int& type, const double& xin, const double &yin,
  442 + double* xout, double *yout)
  443 +{
  444 + // Set transformation constants
  445 + const double psi[] = {0.57477043300, 4.9368292465};
  446 + const double stheta[] = {0.88998808748, -0.88998808748};
  447 + const double ctheta[] = {0.45598377618, 0.45598377618};
  448 + const double phi[] = {4.9368292465, 0.57477043300};
  449 +
  450 + // Perform transformation
  451 + double a = xin - phi[type];
  452 + double b = yin;
  453 + double sb = sin(b);
  454 + double cb = cos(b);
  455 + double cbsa = cb * sin(a);
  456 +
  457 + //
  458 + a = atan2(ctheta[type] * cbsa + stheta[type] * sb, cb * cos(a));
  459 + b = -stheta[type] * cbsa + ctheta[type] * sb;
  460 + if (b > 1.0)
  461 + b = 1.0;
  462 +
  463 + //
  464 + *yout = asin(b);
  465 + *xout = modulo((a+psi[type] + fourpi), twopi);
  466 +
  467 + // Return
  468 + return;
  469 +}
... ...