# Questions tagged [ellipse]

In mathematics, an ellipse is a plane curve that results from the intersection of a cone by a plane in a way that produces a closed curve. Circles are special cases of ellipses, obtained when the cutting plane is orthogonal to the cone's axis. An ellipse is also the locus of all points of the plane whose distances to two fixed points add to the same constant.

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### Transform ellipse representation from major/minor (meters) to degrees

I am given an ellipse represented by a quadruple (major, minor, center, azimuth) where major,minor are the ellips's axis length in meters, the center is the WGS84 coordinates of the ellipse's center ...
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### PostGIS Ellipse Issue

I am trying to create ellipses from fields in my posgres table. I found this custom Ellipse function and have been trying to tweak it to meet my needs. Create Ellipse (x,y,rx,ry,rotation,#of segments ...
202 views

### standard for generating a geolocation error ellipse from lines of position/bearing

Given SEVERAL points, where each point is a line of bearing (LOB)/line of position, and thus each point consists of a (1) latitude & (2) longitude position on the Earth's globe that this LOB is ...
1k views

### Generating true curve elliptical polygons in file geodatabase using ArcPy?

As background, this question arose from trying to answer a question on How to generate overlapping polygons from lines output from Table To Ellipse tool? Using the ArcMap 10.1 GUI it is very easy to ...
420 views

### Creating Ellipse in WGS84 with metric parameters [duplicate]

I have points in WGS84 (x,y), radiuses in meters (rx, ry), rotation angle in degrees. I would like to create a new WGS84 geometry. I've tried this but the major/minor distances seem to be off by a ...
356 views

### How to fit an ellipse around a polygon?

I'm using ArcMap to draw polygons around some geologic features. I want to know the length of the semi major and semi minor axes of the smallest ellipse that would fit around the polygons. I'm a new ...
3k views

### Drawing ellipse with shapely?

How do I draw an ellipse with shapely?
232 views

### Generating series of ellipses on line using ArcGIS Desktop?

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 ...
248 views

### How to draw an ellipse around polygon?

I am trying to ellipses around polygons I have in im map, in ArcGIS 10.4. This what I need in the further steps for displacement of polygons. These polygons are from a geologic map and these specific ...
592 views

### Standard Deviational Ellipse with Open Source Python (GDAL/OGR etc)

I am trying to mimic the Standard Deviational Ellipse tool from ArcGIS through Open Source Python avenues. The formula is here. At the moment I am failing to get the correct X and Y axis lengths for ...
246 views

### How do I get imported KML circles to appear as circles rather than ellipses in QGIS?

I have a QGIS project, CRS is WGS84 (EPSG 4326). I have OpenStreetMap as the base layer. I have loaded some point features. I have created a buffer zone around some of these features with WGS84 as ...
286 views

### Creating ellipse with azimuth according to projected North not to geodetic North with ArcGIS Tool Table to Ellipse?

Table to Ellipse allows the user to create ellipses according to self-defined parameters. One of those parameters is azimuth. As written in the tool help the azimuth refers to the angle 0°-360° ...
139 views

### Create Two Ellipse/Arcs from Straight Line Segments

I have thousands of straight line segments (all separate features). I need to convert each straight line segment into two arcs, with the arcs opposite of each other. For example, I used the XY to Line ...
246 views

### Concentric Ellipses around polygons as a representation of density

I have someone who has given me a thumbnail of a map with some concentric ellipsoids placed in estimated high density locations for our business. One location has three, and two other location have ...
260 views

### Is it possible to create an ellipse around a line in 3D space?

In Postgis 2.1.1, I have a line in 3 dimensional space connecting two antenna points on the earth's surface. Is it possible to create an ellipse around that line? I have a formula to compute the ...