Problems with Grass4.0 on RS/6000 (AIX3.2)

Lee Thomas olo at
Fri Jun 5 11:53:42 EDT 1992

We have just installed Young Minds' RS/6000 version of Grass4.0 on CD.
However, we have some problems that we can't figure out how to fix: 

1)      * i.pca     - Every time I run this I get a WARNING: Too many 
                      iterations in Jacobi routine, output may be 
                      invalid. The eigen values of the transformation
                      matrix above the diagonal are n*e+01 to n*e-01
                      generally. The WARNING message suggests that if
                      these values are not close to zero the Jacobi
                      analysis has failed possibly invalidating the o/p.

                    - If a large region of the image (e.g. 1/4 SPOT scene)
                      is selected for principle components analysis i.pca
                      crashes out of the program with a G_malloc: out of memory
                      before I even get to the warning about the PCA matrix.

2)      * - When I patch together two vector maps created by
                      heads-up digitizing and try to create the required
                      dig_plus file by running I get the following
                      error upon trying to display the output (from 

                      Out of Memory.

                      I can display the two vector files prior to and post
                      to v.patch with no problems. The problem starts after
                      I build their topology using v.suport.

Q. Is there something about memory allocation by GRASS programs that would 
cause  these errors on an IBM RISC 6000 or is this a problem with the way
our machine  has been set up?  We have an RS/6000 320H with 32megs of RAM

Q. Is there any infomation about HOW to use v.digit and  The man
pages are nice but....

If anyone has any ideas about how we could fix these problems we would be
grateful for their help.


-Lee Thomas and Tony Gale

Lee Thomas                              Voice: (512)322-6386
Systems Specialist                        FAX: (512)322-6350
City of Austin Electric Utility      Internet: olo at

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