Plotting Vectors on Map Objects [message #94450] |
Wed, 24 May 2017 12:35  |
emgrono
Messages: 7 Registered: April 2015
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Junior Member |
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Hello.
I am using cgdrawvectors to draw vectors on a map created with map_set. However, while the location of the vectors on the map is correct, the orientation is not relative to the coordinate system of the map, but to the "screen" (there may be a better way to describe this).
I saw in the cgdrawvectors documentation that it may place nice with cgmap objects, and so I thought I would try creating the map as an object with cgmap. This hasn't worked out so easily though. I have been able to draw a map, and do some basic things with it, but I haven't been able to recreate my map.
For example, I couldn't figure out how to recreate the effect of the scale argument in map_set and zoom in. The Limit and xrange/yrange arguments to cgmap do not seem to do this. Any help understanding how to work with map objects would be appreciated. Solutions to the problem described in the first paragraph that don't involve map objects are also welcome.
This is basically what I am trying to recreate:
pa = [0, 0, 1, 1]
scale = 3.2e7
lat = 65
lon = 258
map_set, lat, lon, /stereo, /continents, scale = scale, position = pa, /isotropic, /noborder
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Re: Plotting Vectors on Map Objects [message #94454 is a reply to message #94450] |
Thu, 25 May 2017 05:14  |
emgrono
Messages: 7 Registered: April 2015
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Junior Member |
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I realize now that this approach doesn't help with my original problem. The vectors are still oriented incorrectly. Could someone confirm that cgdrawvectors is only useful with certain map orientations? e.g. ones where north/south is up/down and east/west is right/left, or polar plots where the vectors can be easily rotated.
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