Subscribe to this thread
Home - General / All posts - Create Polygons from Point data
CuDomagoj67 post(s)
#17-Mar-17 14:56

Is that any way to create polygons from point data using value from one field in Point data as key for polygon?


7,903 post(s)
#17-Mar-17 15:36

Using Radian, given a table of points named 'Points' with the geom field 'G' and the order of points defined by the field 'Order', the following will create an area with the points walked in order:


SELECT GeomConvertToArea(GeomConvertToPoint(GeomMergePoints([g]), FALSE))

FROM (SELECT * FROM [points] ORDER BY [order]);

If you are looking for something else, please elaborate.

Andy Sims56 post(s)
#21-Mar-17 13:09

Just in case you are talking about achieving this in Manifold using the GUI, you can link a set of data of form:

X,Y, Poly_ID

to achieve what you are looking for. Select Link Drawing from the file menu and set up the data source (Data can be external or in a Manifold table). Make sure you set the LineID item in the Link drawing dialog to Poly_ID and, on "OK", Manifold will create two drawings, one of points and another of lines. Verify the projection of the lines drawing then unlink the drawing and use the "Bounded Areas" transform to get your polygons.

Note that the input points need to create closed sets of lines for this to work (i.e. Point 1 and Point Last need to be identical)

I'm sure others have more elegant solutions!

Manifold User Community Use Agreement Copyright (C) 2007-2017 Manifold Software Limited. All rights reserved.