[Kstars-devel] branches/kstars/summer/kdeedu/kstars/kstars

[Jason Harris]

Hi Akarsh,

On Fri, Jul 11, 2008 at 7:43 AM, Akarsh Simha <akarshsimha at gmail.com> wrote:
> +    // DEBUG Edit. For testing proper motion. TODO: Remove later
> +    if( name == "Rigel Kentaurus" ) {
> +      // Populate Trail with various positions
> +        KSNumbers num( 2000.0 );
> +      long double jd;
> +      for( jd = 2000.0; jd <= 12000.0; jd += 500.0 ) {
> +       num.updateValues( jd );
> +       double ra, dec;
> +       getIndexCoords( &num, &ra, &dec );
> +       Trail.append( new SkyPoint( ra, dec ) );
> +      }
> +    }

This code isn't right.  the argument of num.updateValues() needs to be
a julian day number, not a year.  You want something like this:

KSNumbers num;
long double jdStart = 1.0 // 1752
long double jdEnd = 5.0e6  //around year 8000
deltaJD = 500.0*365.25 //500 years
for ( jd=jdStart; jd<jdEnd; jd += deltaJD ) {
  num.updateValues( jd );
  ...
}

regards,
Jason