I am trying to create a series of ellipses (mocked up in green below) of defined dimensions along a line. I have got as far as generating regularly spaced points along the line that are attributed with the major (axis perpendicular to line direction) radius r1 and minor (axis parallel to line direction) radius r2.

enter image description here

The aim here is to build a model so that I can go back and easily create new polygons for tweaked values of r1, r2 and varying point geometries (points will always be on a line, and r1, r2 will always have same geometric relationship to line.

I have access to ArcMap and extensions.

  • have you checked the Rectangles Ovals Digitizing plugin, it might have something there already in the code you can review github.com/vinayan/RectOvalDigitPlugin – Antonio Locandro Oct 29 '14 at 17:15
  • There used to be two versions of the Rectangles Ovals plugin. One is a sort-of interactive thing for on-screen digitizing and has been updated for QGIS 2.x ("Rectangles Ovals digitizing") and is not useful for the OP. The other was called "Rectangles Ovals Diamonds" and used to do exactly what the OP wants but has NOT been updated for v2.x (at least not last I looked). It was available for QGIS up to v1.8. I think this is a real shame because of the two it is the one I personally consider more useful as you could set the major and minor axes )height and width) of ellipses. – MappaGnosis Oct 29 '14 at 18:22
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    PS In ArcGIS you can use the Table to Ellipse' tool from Data Management. I'll not put that as an answer as you are really looking for QGIS solutions. – MappaGnosis Oct 29 '14 at 18:30
  • I've asked a question here a few years ago with a similar topic: gis.stackexchange.com/questions/75407/…. It is a PostGIS solution. If it's possible you can transfer this to a Spatialite (coming along with QGIS) solution. Some hints: ellipses (gaia-gis.it/fossil/libspatialite/wiki?name=circles-ellipses), function RotateCoords, shifting geometries with ST_Translate available in newer spatialite versions (=> 3.1) priede.bf.lu.lv/ftp/pub/DatuBazes/SQLite/spatialite/… – Stefan Sep 21 '16 at 6:40

As noted by MappaGnosis in the comments - there is a tool for this in ArcGIS, called Table to Ellipse.

Here is the documentation: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//0017000000tt000000

You will be able to tweak the values in your table and easily recreate the ellipses.

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