star-hitran

commit 13fe40ce8bff5113cb072a3cb60322644413edea
parent 559e6cfe753448531feeee1d22941d9cd09f227d
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Tue, 15 Feb 2022 12:04:19 +0100

Comment the transition member variable isotope_id_local

Diffstat:
M
src/shitran.h
 | 
10
+++++++++-

1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/src/shitran.h b/src/shitran.h
@@ -86,7 +86,15 @@ struct shitran_transition {
   double delta_air; /* Air-pressure wavenumber shift [cm^-1.atm^-1] */
 
   int32_t molecule_id;
-  int32_t isotope_id_local; /* This index starts from 0 */
+
+  /* The value of the following isotopic index is _not_ the value of the
+   * isotopic index read from the HITRAN file. The original value is in [0, 9]
+   * with 0 actually meaning 10. Thus, once decoded, the index is located in
+   * [1, 10]. The next member variable simply stores this index but decremented
+   * by one in order to make it compatible with C indexeing. As a result, it
+   * can be used directly to index the 'isotopes' array of a 'shitran_molecule'
+   * data structure loaded from an isotope metadata file */
+  int32_t isotope_id_local;
 };
 #define SHITRAN_TRANSITION_NULL__ {0,0,0,0,0,0,0,-1,-1}
 static const struct shitran_transition SHITRAN_TRANSITION_NULL =