[Kstars-devel] Proper Motion Corrections - The Right Way

[Jason Harris]

On Wed, Jul 9, 2008 at 2:19 PM, Akarsh Simha <akarshsimha at gmail.com> wrote:
>> One way would be to add code to draw the paths of a few of the high PM
>> stars on the skymap, and then count the number of trixels that they
>> intersect (after having turned on trixel drawing).
>
> Err... how would I do that?
>
I would pick a high PM star (like alpha Centauri or Arcturus), and
make modifications to StarComponent:

+ Add a QList<SkyPoint> member to hold the path of the star over the
allowed time interval

+ in init(), add a loop to fill the list of SkyPoints with the
positions of the star every 500 years or so, using the new formulae
that James found

+ in update(), add a loop to call EquatorialToHorizontal() on each
SkyPoint in the list

+ in draw(), add a loop to connect the points (see
LineListIndex::drawAllLines() for an example).

You'll also need to uncomment the lines that draw trixel boundaries in
the map (skymapcomposite.cpp, lines 253-257).  Then when you run the
program, you can locate the star and count how many trixels its PM
path passes through.

Jason