Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
Hello group... I'm having trouble (idl 5.1; alpha) with map_set limits for 8-element vectors. map_set,lim=[-65,-180, -65,-90, -65,0, -65,90],/grid,/cont,/iso,/ster,-90 ought to work (all pts along 65 S, regularly spaced in longitude) since its a perfectly good square in physical space coordinates. But it doesn't - I get just a single horizontal line and a divide-by-zero. I had a quick look at map_set and just got more confused - it appears to do some convert_coord stuff to work out what limits to use - but how can it do this *before* the map xform is established? Maybe I read it wrong. Whats up? - William -----== Posted via Deja News, The Leader in Internet Discussion ==----- http://www.dejanews.com/rg_mkgrp.xp Create Your Own Free Member Forum
>> wmc@bas.ac.uk wrote: >>> map_set,lim=[-65,-180, -65,-90, -65,0, -65,90],/grid,/cont,/iso,/ster,-90 >>> >>> ought to work (all pts along 65 S, regularly spaced in longitude) >>> since its a perfectly good square in physical space coordinates. Apologies for following up my own post, but RSI have told me the truth so I thought I'd share it. The problem is that, although my points form a square, the first point isn't the bottom left corner. If I'd written: map_set,lim=[-65,-180, -65,-90, -65,0, -65,90],/grid,/cont,/iso,/ster,-90,-90 (making the point (-180,-65) the leftmost point) it would have worked. Hmmm, well I don't find this a completely satisfactory answer. It seems to me that map_set should be able to take 4 points and sort out for itself which one is bottom left, etc. Otherwise you're forced to do this yourself any time there is any doubt. - William William M Connolley | wmc@bas.ac.uk | http://www.nbs.ac.uk/public/icd/wmc/ Climate Modeller, British Antarctic Survey | Disclaimer: I speak for myself -----== Posted via Deja News, The Leader in Internet Discussion ==----- http://www.dejanews.com/rg_mkgrp.xp Create Your Own Free Member Forum