void slaEqecl ( double dr, double dd, double date,
double *dl, double *db )
/*
** - - - - - - - - -
** s l a E q e c l
** - - - - - - - - -
**
** Transformation from J2000.0 equatorial coordinates to
** ecliptic coordinates.
**
** (double precision)
**
** Given:
** dr,dd double J2000.0 mean RA,Dec (radians)
** date double TDB (loosely ET) as Modified Julian Date
** (JD-2400000.5)
** Returned:
** *dl,*db double ecliptic longitude and latitude
** (mean of date, IAU 1980 theory, radians)
**
**
** Called:
** slaDcs2c, slaPrec, slaEpj, slaDmxv, slaEcmat, slaDcc2s,
** slaDranrm, slaDrange
**
**
** Last revision: 31 October 1993
**
** Copyright P.T.Wallace. All rights reserved.
*/
{
double rmat[3][3], v1[3], v2[3];
/* Spherical to Cartesian */
slaDcs2c ( dr, dd, v1 );
/* Mean J2000 to mean of date */
slaPrec ( 2000.0, slaEpj ( date ), rmat );
slaDmxv ( rmat, v1, v2 );
/* Equatorial to ecliptic */
slaEcmat ( date, rmat );
slaDmxv ( rmat, v2, v1 );
/* Cartesian to spherical */
slaDcc2s ( v1, dl, db );
/* Express in conventional ranges */
*dl = slaDranrm ( *dl );
*db = slaDrange ( *db );
}
void projCircle(double racen, double deccen, double radius, double val) {
int i, j, ip, in, sign, pixval;
float mx[NCIRC], my[NCIRC];
double t, axialvec[3], cenvec[3], angvec[3], rotvec[3], rmat[3][3];
double ra[NCIRC], rap[NCIRC], ran[NCIRC];
double dec[NCIRC], decp[NCIRC], decn[NCIRC];
double x, y;
// make Cartesian representation of the vector pointing to center
slaDcs2c(racen, deccen, cenvec);
// make Cartesian representation of a vector pointing radius away
if(deccen>0.0)
slaDcs2c(racen, deccen-radius, angvec);
else
slaDcs2c(racen, deccen+radius, angvec);
t = 0;
for(i=0; i<NCIRC; i++) {
// length of axial vector is angle of rotation
for(j=0;j<3;j++) axialvec[j] = cenvec[j]*t;
// get rotation matrix
slaDav2m(axialvec, rmat);
// apply rotation to angled vector
slaDmxv(rmat, angvec, rotvec);
// get new ra, dec
slaDcc2s(rotvec, &(ra[i]), &(dec[i]));
// if(ra[i] < 0 && racen > 0.0) ra[i] += 2*M_PI;
// if(ra[i] > 0 && racen < 0.0) ra[i] -= 2*M_PI;
// update rotation angle
t += 2.0*M_PI/(double) (NCIRC-1);
}
pixval = rint((__minind*(__maxval-val) + __maxind*(val-__minval))/
(__maxval-__minval));
// saturate properly
pixval = MIN(__maxind, pixval);
pixval = MAX(__minind, pixval);
cpgsci(pixval);
// determine if the polygon wraps around
sign = 0;
for(i=0; i<NCIRC-1; i++) {
if(dec[i]>deccen && ra[i+1]*ra[i] < 0 && ra[i+1]<ra[i]) sign = 1;
}
// if so, draw two polygons separately
if(sign) {
in = 0;
ip = 0;
for(i=0; i<NCIRC; i++) {
if(ra[i]<0.0) {
ran[in] = ra[i]; decn[in] = dec[i]; in++;
}
else {
ran[in] = -0.99999*M_PI; decn[in] = dec[i]; in++;
}
if(ra[i]>0.0) {
rap[ip] = ra[i]; decp[ip] = dec[i]; ip++;
}
else {
rap[ip] = 0.99999*M_PI; decp[ip] = dec[i]; ip++;
}
}
for(i=0; i<ip; i++) {
// Hammer-Aitoff projection
project(rap[i], decp[i], &x, &y);
mx[i] = x; my[i] = y;
}
cpgpoly(ip,mx,my);
for(i=0; i<in; i++) {
// Hammer-Aitoff projection
project(ran[i], decn[i], &x, &y);
mx[i] = x; my[i] = y;
}
cpgpoly(in,mx,my);
}
// otherwise draw only one
else {
for(i=0; i<NCIRC; i++) {
// Hammer-Aitoff projection
project(ra[i], dec[i], &x, &y);
mx[i] = x; my[i] = y;
}
cpgpoly(NCIRC,mx,my);
}
cpgsci(1);
}
