james wrote:
Hello

Ok this is a difficult one (well for me any way)

How do you calculate an objects heilocentric co-ordinates (x,y,z with
the sun at the center) of an object given its Epoch,a,e,i,w,Node,M
values ?


Hi,
One (immodest) suggestion , Go to
http://www.mkas.org.uk/planetfinder.htm and do a "view source" on the page.

I have implemented routines by Paul Schlyter and there is a pointer to
his site which explains it all.

All the best,
JK.