[GRASS-dev] [GRASS GIS] #2122: v.to.db: add eigenvalues of covariance matrix of coordinates

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#2122: v.to.db: add eigenvalues of covariance matrix of coordinates
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Reporter: mlennert | Owner: grass-dev@…
     Type: enhancement | Status: new
Priority: normal | Milestone: 7.0.0
Component: Vector | Version: svn-trunk
Keywords: v.to.db eigenvalues | Platform: Unspecified
      Cpu: Unspecified |
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[Going on with my series of notes on what would be great to have in
GRASS:]

The eigenvalues of the covariance matrix of the coordinates of the
vertices of a polygon represent the major and minor (+ medium in 3D) axes
of an ellipse (ellipsoid in 3D) that approximates the polygon. These
values can be used to approximate different variables in shape analysis
(length, direction, asymmetry, etc). It would be great if v.to.db could
calculate these values.

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Ticket URL: <https://trac.osgeo.org/grass/ticket/2122&gt;
GRASS GIS <http://grass.osgeo.org>

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#2122: v.to.db: new variables to add
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Reporter: mlennert | Owner: grass-dev@…
     Type: enhancement | Status: new
Priority: normal | Milestone: 7.0.0
Component: Vector | Version: svn-trunk
Keywords: v.to.db eigenvalues | Platform: Unspecified
      Cpu: Unspecified |
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Comment(by mlennert):

I'm renaming this to make this into a more general collection of ideas for
variables to add to v.to.db. Feel free to add other ideas.

  * eigenvalues of covariance matrix of coordinates
  * bounding box coordinates

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Ticket URL: <https://trac.osgeo.org/grass/ticket/2122#comment:1&gt;
GRASS GIS <http://grass.osgeo.org>