get convergence

Jan 27, 2010 at 2:25 PM

First off, thanks for creating this, I'm finding it really useful. Is there a function to calculate convergence hidden away somewhere?

Feb 7, 2010 at 3:57 PM
Edited Feb 7, 2010 at 3:58 PM

No, but could you eloborate on what you exactly mean by that? "Convergence" is a very general mathematical term (it's actually used to calculate the UTM transformation), but I'm not sure what you mean by this in the context of map projections.

Feb 8, 2010 at 8:48 PM
Edited Feb 8, 2010 at 8:48 PM

Sorry, that was a bit vague, I was just looking to calculate the difference between grid north and true north for specific positions. I thought I would ask before I started re-inventing wheels.

I managed to calculate it in the end for TM projections, (not exactly correct results, but pretty close though).