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I am trying to plot velocities (from GPS data) as arrows in ArcGIS 10.3. Say the velocity at one point is 20 mm/y and at another point 40 mm/y. I will worry about the direction later - let us assume it is straight north. I would like to symbolize the data points as arrows starting at the coordinates of the datapoint, going straight north and with a length of respectively 20-times some unit and 40-times some unit.

I know I can use arrow symbols when using the "Symbology - Quantities - Graduated symbols" but that does not scale each arrow exactly by the value in question. For "Symbology - Quantities - Proportional symbols", I can only figure out how to make the size of squares or circles proportional to some value but not the length of an arrow.

Has anyone done this?

If it is not doable in Arc - is there some open source GIS that can do that?

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There is a plugin in QGIS called Vector field renderer that can do what you asking for. Based on the description below it

Renders a point layer with arrows representing vectors. The size and orientation of the arrow is data defined. Typically this would be used to represent movement, fluid flow or ground deformation for example. The plugin can also draw an ellipse representing the error covariance of the vector. The scale of the arrows can be easily changed using buttons on the toolbar. The plugin also can draw a scale box on the map.

I tested the plugin in QGIS 2.16.1, and this a screenshot of the initial output based on values from a field:

enter image description here

But it has many options that you can try it by yourself:

enter image description here

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  • Thanks a lot - i will give this a shot. This looks nice. Since I never used QGIS, it might take me a moment to figure things out but I will get back to you. – NAB Aug 4 '16 at 7:20
  • Thanks - that plugin worked fine. I am getting some python error and I cannot change the color etc. but as long as the arrows have the right length, I am doing the rest in illustrator. Thanks – NAB Aug 6 '16 at 15:30
  • Any solution for doing this in ArcGIS? Thanks. – dmariamp Nov 17 '16 at 23:52
  • I am not aware if this function available in ArcGIS. The closest that I know is to use proportional symbololgy: pro.arcgis.com/en/pro-app/help/mapping/symbols-and-styles/… – ahmadhanb Nov 18 '16 at 5:13

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