Timeline for How to plot a vector field on a geographic map?
Current License: CC BY-SA 3.0
10 events
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| Jun 22, 2016 at 22:33 | comment | added | unlikely | Any idea to accomplish this? | |
| Jun 22, 2016 at 7:55 | comment | added | Kuba | @unlikely both are ok, depends what is needed. Your is probably more intuitive. Just wanted to clarify your needs. | |
| Jun 22, 2016 at 7:50 | comment | added | unlikely |
I don't know what is better or if there is some convention or accepted standard. I think that "my" approach, while maybe not as correct as yours, make easier to immediately understand where the field is more intense, without having to mentally deduct the effect of map stretching. What do you think? Maybe we can resort to use a StreamPlot like you did just to avoid this possible ambiguity.
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| Jun 22, 2016 at 7:50 | comment | added | unlikely | My idea was just to get a "nice" (uniform, well segmented) plot. But I understand what you means. And you are right, with "my" approach, I expect that a constant magnitude vector field is plotted with equal length arrows everywhere. Your idea to stretch the arrow length according to the stretching of the map does also make sense, particularly if the field represent something length-related. | |
| Jun 22, 2016 at 7:30 | comment | added | Kuba | @unlikely Arrows lengths are reflecting the magnitude of the field, when regions near poles are streched then those arrows will become longer which will reflect intensity but maybe you want {1,1} vector to be the same length on differently stretched regions, like in your example. | |
| Jun 22, 2016 at 7:27 | comment | added | Kuba |
@unlikely p.s. when I use GeoGraphicsVectorPlot[{x, y} // Normalize, {x, y, z}, it doesn't look right, unless I'm missing something, but VectorPlot[{x, y} // Normalize, {x, -Pi, Pi}, {y, -Pi/2, Pi/2} is ok.
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| Jun 22, 2016 at 7:27 | comment | added | unlikely | Not sure to understand your question... | |
| Jun 22, 2016 at 7:22 | comment | added | Kuba | @unlikely I see, so you want the distribution uniform. What about arrows lengths, should the same magnitude near pole for Mercator be longer than near equator? | |
| Jun 22, 2016 at 6:14 | comment | added | unlikely | Something like this, yes. But I have two problems: 1) my field is defined in term of XYZ coords, not lat/long; 2) the stream lines are well distributed and well segmented in the preliminary graphic but in some projection (for example Mercator) become very distant and with segments very long near the poles. My tentative to work in the projected domain was to avoid this. | |
| Jun 21, 2016 at 19:42 | history | answered | Kuba | CC BY-SA 3.0 |