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Re: GEOSTATS: map comparisons

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  • Edzer J. Pebesma
    ... Maps can be compared in many different ways. Suppose you re interested in the difference between both maps. If you want only differences, subtracting the
    Message 1 of 2 , Oct 30, 1997
      Brad Robbins (BIO) wrote:
      >
      > I am interested in the spatial relationship between two
      > variables. So I've sampled an area for both variables and
      > then interpolated these values across the area.
      > Now I want to compare these two surfaces.
      >
      > Question:
      > How can I or do I need to consider interpolation error when
      > comparing these maps?

      Maps can be compared in many different ways. Suppose you're
      interested in the difference between both maps.

      If you want only differences, subtracting the maps is enough.

      If you want to say something like the difference being
      clearly different from zero or not, you should consider the
      interpolation error variance of both variables, as well as their
      covariance. This is obtained by cokriging, using a program
      that reports cokriging prediction error covariances. One program
      that can report prediction error covariances is gstat, found at
      http://www.frw.uva.nl/~pebesma/gstat
      --
      Edzer
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