Changeset 2551 in Sophya for trunk/SophyaExt/XephemAstroLib/riset.c

Timestamp:

Jun 15, 2004, 6:54:12 PM (21 years ago)

Author:

cmv

Message:

nouvelle version de xephem/libastro (3.6) cmv 15/6/04

File:

• trunk/SophyaExt/XephemAstroLib/riset.c (modified) (7 diffs)

trunk/SophyaExt/XephemAstroLib/riset.c

@@ -2 +2 @@
 #include <math.h>
 
-#include "P_.h"
 #include "astro.h"
 
 /* given the true geocentric ra and dec of an object, the observer's latitude,
- *   lat, and a horizon displacement correction, dis, all in radians, find the
+ *   lt, and a horizon displacement correction, dis, all in radians, find the
  *   local sidereal times and azimuths of rising and setting, lstr/s
  *   and azr/s, also all in radians, respectively.
@@ -25 +24 @@
  */
 void
-riset (ra, dec, lat, dis, lstr, lsts, azr, azs, status)
-double ra, dec;
-double lat, dis;
-double *lstr, *lsts;
-double *azr, *azs;
-int *status;
+riset (double ra, double dec, double lt, double dis, double *lstr,
+double *lsts, double *azr, double *azs, int *status)
 {
 #define EPS     (1e-9)  /* math rounding fudge - always the way, eh? */
@@ -40 +35 @@
         int shemi;              /* flag for southern hemisphere reflection */
 
-        /* reflect lat and dec if in southern hemisphere, then az back later */
-        if ((shemi= (lat < 0.)) != 0) {
-            lat = -lat;
+        /* reflect lt and dec if in southern hemisphere, then az back later */
+        if ((shemi= (lt < 0.)) != 0) {
+            lt = -lt;
             dec = -dec;
         }
@@ -48 +43 @@
         /* establish zenith angle, and its extrema */
         z = (PI/2.) + dis;
-        zmin = fabs (dec - lat);
-        zmax = PI - fabs(dec + lat);
+        zmin = fabs (dec - lt);
+        zmax = PI - fabs(dec + lt);
 
         /* first consider special cases.
@@ -64 +59 @@
 
         /* compute rising hour angle -- beware found off */
-        cos_h = (cos(z)-sin(lat)*sin(dec))/(cos(lat)*cos(dec));
+        cos_h = (cos(z)-sin(lt)*sin(dec))/(cos(lt)*cos(dec));
         if (cos_h >= 1.)
             h =  0.;
@@ -73 +68 @@
 
         /* compute setting azimuth -- beware found off */
-        xaz = sin(dec)*cos(lat)-cos(dec)*cos(h)*sin(lat);
+        xaz = sin(dec)*cos(lt)-cos(dec)*cos(h)*sin(lt);
         yaz = -1.*cos(dec)*sin(h);
         if (xaz == 0.) {
@@ -103 +98 @@
 
 /* For RCS Only -- Do Not Edit */
-static char *rcsid[2] = {(char *)rcsid, "@(#) $RCSfile: riset.c,v $ $Date: 2001-10-22 12:08:28 $ $Revision: 1.2 $ $Name: not supported by cvs2svn $"};
+static char *rcsid[2] = {(char *)rcsid, "@(#) $RCSfile: riset.c,v $ $Date: 2004-06-15 16:52:40 $ $Revision: 1.3 $ $Name: not supported by cvs2svn $"};