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

AI-GEOSTATS: singular matrix during conditional simulation

Expand Messages
  • Ulrich Leopold
    Dear list, I encounter a problem in Gstat. I posted my message to the Gstat list but get currently no answer. Maybe someone here experienced this problem
    Message 1 of 2 , Jul 15, 2003
      Dear list,

      I encounter a problem in Gstat. I posted my message to the Gstat list but get currently no answer.
      Maybe someone here experienced this problem already in Gstat or has any ideas how to solve it:

      Gstat terminates with the message "matrix library error: singular
      matrix" (see below). The trouble shooting in the manual says: Increase the value of zero.
      I did that. Nothing changes. Another solution is to average values at identical locations.
      I did that as well with the average option in data().

      I had a look to the debug file but do not quite get a clue from it except that the last matrix
      has 2 identical columns?? That's when Gstat stops. You can find that matrix below as well.
      Any ideas how to solve this problem?

      Ulrich

      ---------------------------------------------------------------

      gstat: Linux version 2.4.2 (26 April 2003)
      Copyright (C) 1992, 2003 Edzer J. Pebesma
      using Marsaglia's random number generator

      [using conditional gaussian simulation]
      initializing maps .
      0% done
      "chfactor.c", line 130: singular matrix in function LDLfactor()

      gstat caught an error that occurred in the matrix library,
      the reason for it was: singular matrix

      HINT: Read the manual (http://www.geog.uu.nl/gstat/manual)
      look for: Trouble shooting -> Error messages -> From meschach

      gstat: matrix library error: singular matrix

      --------------------------------------------------------------------

      idx x:;y:;z:;v:;
      0 x: 254083 y: 552263 z: 0 weight: 1

      # Covariances (x_i, x_j) matrix C (lower triangle only):
      Matrix: 10 by 10
      row 0: 174.0506 0 0 0
      0 0 0 0 0
      0
      row 1: 174.0506 174.0506 0 0
      0 0 0 0 0
      0
      row 2: 45.0007921 45.0007921 174.0506 0
      0 0 0 0 0
      0
      row 3: 43.8068348 43.8068348 37.2124655 174.0506
      0 0 0 0 0
      0
      row 4: 43.4219499 43.4219499 36.9949687 52.578787
      174.0506 0 0 0 0
      0
      row 5: 40.3552653 40.3552653 36.7606584 43.6115366
      44.1867844 52.612507 0 0 0
      0
      row 6: 38.927339 38.927339 42.9203931 34.49808
      34.5784392 38.2033244 52.612507 0 0
      0
      row 7: 45.4024655 45.4024655 38.5251957 45.9125721
      45.1916088 38.2033244 33.2536242 52.612507 0
      0
      row 8: 43.4915577 43.4915577 36.7949906 52.0550197
      51.3836065 42.5157124 33.7749338 46.6269808 174.0506
      0
      row 9: 40.7441753 40.7441753 48.2783442 33.6299795
      33.4342596 33.6128998 42.2386301 35.0813766 33.260144
      174.0506

      -----------------------------------------------------------------------------


      --
      __________________________________________________

      Ulrich Leopold MSc.

      Department of Physical Geography
      Institute for Biodiversity and Ecosystem Dynamics
      Faculty of Science
      University of Amsterdam
      Nieuwe Achtergracht 166
      NL-1018WV Amsterdam

      Phone: +31-(0)20-525-7456 (7451 Secretary)
      Fax: +31-(0)20-525-7431
      Email: uleopold@...
      http://www.frw.uva.nl/soil/Welcome.html

      Check us also out at:
      Netherlands Centre for Geo-ecological Research
      http://www.frw.uva.nl/icg





      --
      * To post a message to the list, send it to ai-geostats@...
      * As a general service to the users, please remember to post a summary of any useful responses to your questions.
      * To unsubscribe, send an email to majordomo@... with no subject and "unsubscribe ai-geostats" followed by "end" on the next line in the message body. DO NOT SEND Subscribe/Unsubscribe requests to the list
      * Support to the list is provided at http://www.ai-geostats.org
    • Rajive Ganguli, Ph.D.
      I do not anything about GSLIB, but when two rows or cols in a matrix are identical, the determinant of the matrix is zero. A matrix is called singular when its
      Message 2 of 2 , Jul 15, 2003
        I do not anything about GSLIB, but when two rows or cols in a matrix are
        identical, the determinant of the matrix is zero. A matrix is called
        singular when its det. is zero. A singular matrix cannot be inverted.

        Note that it is also possible for the product of two matrices to have a zero
        determinant, without each of them being zero.


        Rajive Ganguli, Ph.D., P.E., C.O.I
        Associate Professor of Mining Engineering
        University of Alaska Fairbanks
        =====
        Office: 317 Duckering Building
        Mailing Add: Box 755800, Fairbanks, AK 99775
        ph: 907-474-7631, fax: 907-474-6635
        web: http://www.faculty.uaf.edu/ffrg/




        > -----Original Message-----
        > From: ai-geostats-list@... [mailto:ai-geostats-list@...]On
        > Behalf Of Ulrich Leopold
        > Sent: Tuesday, July 15, 2003 3:25 AM
        > To: ai-geostats@...
        > Subject: AI-GEOSTATS: singular matrix during conditional simulation
        >
        >
        > Dear list,
        >
        > I encounter a problem in Gstat. I posted my message to the
        > Gstat list but get currently no answer.
        > Maybe someone here experienced this problem already in Gstat
        > or has any ideas how to solve it:
        >
        > Gstat terminates with the message "matrix library error: singular
        > matrix" (see below). The trouble shooting in the manual says:
        > Increase the value of zero.
        > I did that. Nothing changes. Another solution is to average
        > values at identical locations.
        > I did that as well with the average option in data().
        >
        > I had a look to the debug file but do not quite get a clue
        > from it except that the last matrix
        > has 2 identical columns?? That's when Gstat stops. You can
        > find that matrix below as well.
        > Any ideas how to solve this problem?
        >
        > Ulrich
        >
        > ---------------------------------------------------------------
        >
        > gstat: Linux version 2.4.2 (26 April 2003)
        > Copyright (C) 1992, 2003 Edzer J. Pebesma
        > using Marsaglia's random number generator
        >
        > [using conditional gaussian simulation]
        > initializing maps .
        > 0% done
        > "chfactor.c", line 130: singular matrix in function LDLfactor()
        >
        > gstat caught an error that occurred in the matrix library,
        > the reason for it was: singular matrix
        >
        > HINT: Read the manual (http://www.geog.uu.nl/gstat/manual)
        > look for: Trouble shooting -> Error messages -> From meschach
        >
        > gstat: matrix library error: singular matrix
        >
        > --------------------------------------------------------------------
        >
        > idx x:;y:;z:;v:;
        > 0 x: 254083 y: 552263 z: 0 weight: 1
        >
        > # Covariances (x_i, x_j) matrix C (lower triangle only):
        > Matrix: 10 by 10
        > row 0: 174.0506 0 0 0
        > 0 0 0 0
        > 0
        > 0
        > row 1: 174.0506 174.0506 0 0
        > 0 0 0 0
        > 0
        > 0
        > row 2: 45.0007921 45.0007921 174.0506 0
        > 0 0 0 0
        > 0
        > 0
        > row 3: 43.8068348 43.8068348 37.2124655 174.0506
        > 0 0 0 0
        > 0
        > 0
        > row 4: 43.4219499 43.4219499 36.9949687 52.578787
        > 174.0506 0 0 0
        > 0
        > 0
        > row 5: 40.3552653 40.3552653 36.7606584 43.6115366
        > 44.1867844 52.612507 0 0
        > 0
        > 0
        > row 6: 38.927339 38.927339 42.9203931 34.49808
        > 34.5784392 38.2033244 52.612507 0
        > 0
        > 0
        > row 7: 45.4024655 45.4024655 38.5251957 45.9125721
        > 45.1916088 38.2033244 33.2536242 52.612507
        > 0
        > 0
        > row 8: 43.4915577 43.4915577 36.7949906 52.0550197
        > 51.3836065 42.5157124 33.7749338 46.6269808
        > 174.0506
        > 0
        > row 9: 40.7441753 40.7441753 48.2783442 33.6299795
        > 33.4342596 33.6128998 42.2386301 35.0813766
        > 33.260144
        > 174.0506
        >
        > --------------------------------------------------------------
        > ---------------
        >
        >
        > --
        > __________________________________________________
        >
        > Ulrich Leopold MSc.
        >
        > Department of Physical Geography
        > Institute for Biodiversity and Ecosystem Dynamics
        > Faculty of Science
        > University of Amsterdam
        > Nieuwe Achtergracht 166
        > NL-1018WV Amsterdam
        >
        > Phone: +31-(0)20-525-7456 (7451 Secretary)
        > Fax: +31-(0)20-525-7431
        > Email: uleopold@...
        > http://www.frw.uva.nl/soil/Welcome.html
        >
        > Check us also out at:
        > Netherlands Centre for Geo-ecological Research
        > http://www.frw.uva.nl/icg
        >
        >
        >
        >
        >
        > --
        > * To post a message to the list, send it to ai-geostats@...
        > * As a general service to the users, please remember to post
        > a summary of any useful responses to your questions.
        > * To unsubscribe, send an email to majordomo@... with no
        > subject and "unsubscribe ai-geostats" followed by "end" on
        > the next line in the message body. DO NOT SEND
        > Subscribe/Unsubscribe requests to the list
        > * Support to the list is provided at http://www.ai-geostats.org
        >


        --
        * To post a message to the list, send it to ai-geostats@...
        * As a general service to the users, please remember to post a summary of any useful responses to your questions.
        * To unsubscribe, send an email to majordomo@... with no subject and "unsubscribe ai-geostats" followed by "end" on the next line in the message body. DO NOT SEND Subscribe/Unsubscribe requests to the list
        * Support to the list is provided at http://www.ai-geostats.org
      Your message has been successfully submitted and would be delivered to recipients shortly.