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Re: [ai-geostats] comparing variograms?

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  • José-Manuel Blanco-Moreno
    Hello, Try: SCHABENBERGER O & PIERCE FJ (2002) Contemporary statistical models for the plant and soil sciences. CRC Press, Boca Raton, Florida. They compare
    Message 1 of 3 , Oct 18, 2004
      Hello,
      Try:
      SCHABENBERGER O & PIERCE FJ (2002) Contemporary statistical models for
      the plant and soil sciences. CRC Press, Boca Raton, Florida.

      They compare theoretical semivariograms between treatments through non
      linear regression. They use something like to the extra sum of squares.
      Details on this one on:
      RATKOWSKY DA (1983) Nonlinear Regression Modeling: a Unified Practical
      Approach. M. Dekker, New York.

      However, it does not convince me. From my point of view, comparisson of
      spatial structures through non linear regression is a kind of artifact.

      And remember:
      “He uses statistics as a drunken man uses lamp-posts... for support
      rather than illumination." - Andrew Lang
      or
      "Statistics are like bikinis. What they reveal is suggestive, but what
      they conceal is vital" - Aaron Levenstein
      or
      "Torture numbers, and they'll confess to anything" - Gregg Easterbrook



      George R Cutter wrote:

      >Dear ai-geostats Members,
      >
      >Are there appropriate statistical tests for determining whether empirical
      >variograms are statistically different (maybe something akin to a
      >Kolmogorov-Smirnoff or chi-square test)?
      >
      >Is there a test for comparing variogram model parameters?
      >
      >If not, why? If so, what assumptions are required?
      >
      >Does anyone know of a published reference where such comparisons have been made?
      >
      >Thank you,
      >Randy Cutter.
      >
      >-------------------------------------
      >University of New Hampshire
      >Center for Coastal and Ocean Mapping
      >Chase Ocean Engineering Lab,
      >24 Colovos Rd., Durham, NH 03824
      >Phone 603-862-0564 Fax 603-862-0839
      >email - gcutter@...
      >CCOM website: http://www.ccom.unh.edu
      >-------------------------------------
      >
      >
      >

      --
      José Manuel Blanco Moreno
      Ph.D Student

      ---------------------------------------
      José-Manuel Blanco-Moreno

      Dept. de Biologia Vegetal (Botànica)
      Universitat de Barcelona
      Av. Diagonal 645
      08028 Barcelona
      SPAIN
      ---------------------------------------

      phone: (+34)93.402.1471
      fax: (+34)93.411.2842
      e-mail: jmblanco@...
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