Loading ...
Sorry, an error occurred while loading the content.

1643Re: [ai-geostats] std deviation when using SGSIM

Expand Messages
  • Oriol Falivene
    Jul 20 6:36 AM
    • 0 Attachment
      Thanks Julian,

      I was doing unconditional simulation and the ranges were to large. I've made
      some tests and each range should be at least 1/10 the grid dimensions to obtain
      a good match of the standard deviation. There is any literature regarding this
      issue?

      Regards.

      Oriol

      Julián Ortiz wrote:

      > Hello,
      >
      > This may be due to conditioning data that lower the std. dev. of your
      > realizations.
      > If you want to fix this, you could use the program TRANS in GSLIB and refer
      > to the
      > paper:
      >
      > "Posterior Identification of Histograms Conditional to Local Data, by A. G.
      > Journel and W. Xu,
      > Mathematical Geology, 26(3):323-359, 1994.
      >
      > If you are doing unconditional simulation, the lower std. dev. may be due to
      > the size of your
      > field as compared to the range of your variogram.
      >
      > Best regards,
      >
      > Julián Ortiz C., Ph. D.
      > Profesor Asistente
      > Departamento de Ingeniería de Minas
      > Universidad de Chile
      >
      > Fono: +56 2 678 4585
      > Fax : +56 2 672 3504
      > Web : www.ualberta.ca/~jmo1
      >
      > -----Mensaje original-----
      > De: Oriol Falivene [mailto:ofaliven@...]
      > Enviado el: martes, 20 de julio de 2004 4:00
      > Para: ai-geostats@...
      > Asunto: [ai-geostats] std deviation when using SGSIM
      >
      > Hello,
      >
      > We're using SGSIM from GSLIB to create gaussian fields of standard
      > deivation = 1.
      > We realize that the standard deviation is always underestimated, tipical
      > obtianed values are betwee 0.7 and 0.9.
      > How can I get the correct std. dev?
      >
      > Regards
      >
      > --
      >
      > ______________________________________
      >
      > Oriol Falivene
      > ofaliven@...
      > http://www.ub.es/ggac
      >
      > tel. (+34) 93 4021373
      > fax (+34) 93 4021340
      >
      > Fac. de Geologia,
      > Univ. de Barcelona

      --



      ______________________________________

      Oriol Falivene
      ofaliven@...
      http://www.ub.es/ggac

      tel. (+34) 93 4021373
      fax (+34) 93 4021340

      Fac. de Geologia,
      Univ. de Barcelona
    • Show all 3 messages in this topic