VSOP87 full set and data pointers

libastro/Makefile

@@ -80,7 +80,14 @@ OBJS =			\
 	umoon.o		\
 	twobody.o	\
 	vsop87.o	\
-	vsop87_data.o
+	vsop87_ear.o	\
+	vsop87_jup.o	\
+	vsop87_mar.o	\
+	vsop87_mer.o	\
+	vsop87_nep.o	\
+	vsop87_sat.o	\
+	vsop87_ura.o	\
+	vsop87_ven.o
 
 libastro.a: $(HS) $(OBJS)
 	ar rv $@ $(OBJS)

libastro/astro.h

@@ -808,7 +808,7 @@ extern void utc_gst (double m, double utc, double *gst);
 extern void gst_utc (double m, double gst, double *utc);
 
 /* vsop87.c */
-extern int vsop87 (double m, int obj, double prec, double *ret);
+extern int vsop87 (double m, int obj, double *ret);
 
 #endif /* _ASTRO_H */
 

libastro/plans.c

@@ -10,7 +10,7 @@
 
 static void pluto_ell (double mj, double *ret);
 static void chap_trans (double mj, double *ret);
-static void planpos (double mj, int obj, double prec, double *ret);
+static void planpos (double mj, int obj, double *ret);
 
 /* coordinate transformation
  * from:
@@ -79,18 +79,18 @@ double *ret)	/* ecliptic coordinates {l,b,r} at equinox of date */
  * (not corrected for light-time)
  */
 static void
-planpos (double mj, int obj, double prec, double *ret)
+planpos (double mj, int obj, double *ret)
 {
 	if (mj >= CHAP_BEGIN && mj <= CHAP_END) {
 	    if (obj >= JUPITER) {		/* prefer Chapront */
-		chap95(mj, obj, prec, ret);
+		chap95(mj, obj, 0.0, ret);
 		chap_trans (mj, ret);
 	    } else {				/* VSOP for inner planets */
-		vsop87(mj, obj, prec, ret);
+		vsop87(mj, obj, ret);
 	    }
 	} else {				/* outside Chapront time: */
 	    if (obj != PLUTO) {			/* VSOP for all but Pluto */
-		vsop87(mj, obj, prec, ret);
+		vsop87(mj, obj, ret);
 	    } else {				/* Pluto mean elliptic orbit */
 		pluto_ell(mj, ret);
 	    }
@@ -175,7 +175,7 @@ double *rho0, double *lam, double *bet, double *dia, double *mag)
 	     * retarded for light time in second pass;
 	     * alternative option:  vsop allows calculating rates.
 	     */
-	    planpos(mj - dt, p, 0.0, ret);
+	    planpos(mj - dt, p, ret);
 
 	    lp = ret[0];
 	    bp = ret[1];

libastro/sun.c

@@ -27,7 +27,7 @@ sunpos (double mj, double *lsn, double *rsn, double *bsn)
 	    return;
 	}
 
-	vsop87(mj, SUN, 0.0, ret);	/* full precision earth pos */
+	vsop87(mj, SUN, ret);	/* full precision earth pos */
 
 	*lsn = ret[0] - PI;		/* revert to sun pos */
 	range (lsn, 2*PI);		/* normalise */

libastro/vsop87.c

@@ -94,79 +94,67 @@
  *    return:     error index (int)
  *                 0: no error.
  *		   2: object out of range [MERCURY .. NEPTUNE, SUN]
- *		   3: precision out of range [0.0 .. 1e-3]
  ******************************************************************/
-int
-vsop87 (double mj, int obj, double prec, double *ret)
-{
-    static double (*vx_map[])[3] = {		/* data tables */
-		vx_mercury, vx_venus, vx_mars, vx_jupiter,
-		vx_saturn, vx_uranus, vx_neptune, 0, vx_earth,
-	};
-    static int (*vn_map[])[3] = {		/* indexes */
-		vn_mercury, vn_venus, vn_mars, vn_jupiter,
-		vn_saturn, vn_uranus, vn_neptune, 0, vn_earth,
-	};
-    static double a0[] = {	/* semimajor axes; for precision ctrl only */
-	    0.39, 0.72, 1.5, 5.2, 9.6, 19.2, 30.1, 39.5, 1.0,
-	};
-    double (*vx_obj)[3] = vx_map[obj];		/* VSOP87 data and indexes */
-    int (*vn_obj)[3] = vn_map[obj];
+/******************************************************************
+ * added entire vsop87 data set (31577 terms)
+ * change use of indexes for pointers
+ * delete VSOP_SCALE macro
+ * delete precision control as always called with 0 (full precision)
+ * Gustavo A. Corradi - Dec - 2022 (gcorrad@gmail.com)
+ ******************************************************************/
 
+extern t_vsop87v 
+    *mercury_vs[], *venus_vs[], *mars_vs[], *jupiter_vs[],
+    *saturn_vs[], *uranus_vs[], *neptune_vs[], *earth_vs[];
+
+int
+vsop87 (double mj, int obj, double *ret)
+{
+    static t_vsop87v **map_obj[] = {	
+        mercury_vs, venus_vs, mars_vs, jupiter_vs,
+	    saturn_vs, uranus_vs, neptune_vs, 0, earth_vs,
+    };
     double t[VSOP_MAXALPHA+1];			/* powers of time */
-    double t_abs[VSOP_MAXALPHA+1];		/* powers of abs(time) */
-    double q;					/* aux for precision control */
-    int i, cooidx, alpha;			/* misc indexes */
+    double term, arg, mj0;
+#if VSOP_GETRATE
+    double termdot;
+#endif
+    t_vsop87 *p; /* VSOP87 term pointer */
+    t_vsop87v *pp, **vsp; /* VSOP87 variable and planet pointer */
+    int i, cooidx, alpha, maxt; /* misc indexes */
 
     if (obj == PLUTO || obj > SUN)
-	return (2);
-
-    if (prec < 0.0 || prec > 1e-3)
-	return(3);
+	    return (2);
 
+    vsp = map_obj[obj];
     /* zero result array */
     for (i = 0; i < 6; ++i) ret[i] = 0.0;
 
     /* time and its powers */
+    mj0 = (mj - J2000)/VSOP_A1000;
     t[0] = 1.0;
-    t[1] = (mj - J2000)/VSOP_A1000;
-    for (i = 2; i <= VSOP_MAXALPHA; ++i) t[i] = t[i-1] * t[1];
-    t_abs[0] = 1.0;
-    for (i = 1; i <= VSOP_MAXALPHA; ++i) t_abs[i] = fabs(t[i]);
-
-    /* precision control */
-    q = -log10(prec + 1e-35) - 2;	/* decades below 1e-2 */
-    q = VSOP_ASCALE * prec / 10.0 / q;	/* reduce threshold progressively
-					 * for higher precision */
+    t[1] = mj0;
+    for (i = 2; i <= VSOP_MAXALPHA; ++i) t[i] = t[i-1] * mj0;
 
     /* do the term summation; first the spatial dimensions */
     for (cooidx = 0; cooidx < 3; ++cooidx) {
 
-	/* then the powers of time */
-	for (alpha = 0; vn_obj[alpha+1][cooidx] ; ++alpha) {
-	    double p, term, termdot;
+        /* then the powers of time */
+        pp = vsp[cooidx];
+	    for (alpha = 0; pp->vars; ++alpha, ++pp) {
 
-	    /* precision threshold */
-	    p= alpha ? q/(t_abs[alpha] + alpha*t_abs[alpha-1]*1e-4 + 1e-35) : q;
-#if VSOP_SPHERICAL
-	    if (cooidx == 2)	/* scale by semimajor axis for radius */
-#endif
-		p *= a0[obj];
-
-	    term = termdot = 0.0;
-	    for (i = vn_obj[alpha][cooidx]; i < vn_obj[alpha+1][cooidx]; ++i) {
-		double a, b, c, arg;
-
-		a = vx_obj[i][0];
-		if (a < p) continue;	/* ignore small terms */
-
-		b = vx_obj[i][1];
-		c = vx_obj[i][2];
-
-		arg = b + c * t[1];
-		term += a * cos(arg);
+            maxt = pp->maxt;
+            p = pp->vars;
+            term = 0.0;
 #if VSOP_GETRATE
-		termdot += -c * a * sin(arg);
+            termdot = 0.0;  
+#endif
+            for (i = 0; i < maxt; ++i, ++p) {
+
+		        arg = p->B + p->r * mj0;
+		        term += p->L * cos(arg);
+#if VSOP_GETRATE
+		        termdot += -p->r * p->L * sin(arg);
 #endif
 	    }
 
@@ -178,8 +166,6 @@ vsop87 (double mj, int obj, double prec, double *ret)
 	} /* alpha */
     } /* cooidx */
 
-    for (i = 0; i < 6; ++i) ret[i] /= VSOP_ASCALE;
-
 #if VSOP_SPHERICAL
     /* reduce longitude to 0..2pi */
     ret[0] -= floor(ret[0]/(2.*PI)) * (2.*PI);
@@ -193,7 +179,7 @@ vsop87 (double mj, int obj, double prec, double *ret)
 #if VSOP_SPHERICAL
     /* reduction from dynamical equinox of VSOP87 to FK5;
      */
-    if (prec < 5e-7) {		/* 5e-7 rad = 0.1 arc seconds */
+    {
 	double L1, c1, s1;
 	L1 = ret[0] - degrad(13.97 * t[1] - 0.031 * t[2]);
 	c1 = cos(L1); s1 = sin(L1);

libastro/vsop87.h

@@ -1,5 +1,5 @@
 /* Position of planets mercury to neptune; from:
-ftp://ftp.bdl.fr/pub/ephem/planets/vsop87/
+ftp://ftp.imcce.fr/pub/ephem/planets/vsop87/
 from README:
 
 ==========================                         ===========================
@@ -60,31 +60,33 @@ reports to:                    E-mail     : comments@bdl.fr
 ==============================================================================
   implemented for C: stern
 */
+/******************************************************************
+ * added entire vsop87 data set (31577 terms)
+ * change use of indexes for pointers
+ * delete VSOP_SCALE macro
+ * delete precision control as always called with 0 (full precision)
+ * Gustavo A. Corradi - Dec - 2022 (gcorrad@gmail.com)
+ ******************************************************************/
 
-#define VSOP_ASCALE	1e8	/* amplitude factor as stored */
+#ifndef _VSOP87_H_
+#define _VSOP87_H_
 
 /* coding flags */
 #define VSOP_SPHERICAL	1	/* version in data.c uses spherical coords */
 #define VSOP_GETRATE	0	/* calculate time derivatives of coordinates */
 
-/* data tables */
-extern double vx_mercury[][3];
-extern int vn_mercury[][3];
-extern double vx_venus[][3];
-extern int vn_venus[][3];
-extern double vx_earth[][3];
-extern int vn_earth[][3];
-extern double vx_mars[][3];
-extern int vn_mars[][3];
-extern double vx_jupiter[][3];
-extern int vn_jupiter[][3];
-extern double vx_saturn[][3];
-extern int vn_saturn[][3];
-extern double vx_uranus[][3];
-extern int vn_uranus[][3];
-extern double vx_neptune[][3];
-extern int vn_neptune[][3];
 
-extern int vsop87 (double mj, int obj, double prec, double *ret);
+typedef struct s_vsop87 {
+    double L;
+    double B;
+    double r;
+} t_vsop87;
 
+typedef struct s_vsop87v {
+    t_vsop87    *vars;
+    int         maxt;
+} t_vsop87v;
+   
+extern int vsop87 (double mj, int obj, double *ret);
 
+#endif /* _VSOP87_H_ */