Hi all, Again thanks for your comments. I guess i can not define the problem correctly. I have a sequantial fortran code giving me the global matrix of 200000x200000. The code writes the matrix in a binary file at little endian mode (i can write only the nonzero terms or the entire matrix). I tried to change the binary mode to big endian and read the global matrix by a c program as in the example /src/mat/example/tests/ex31.c. However the program reads binary file wrong and gives the following error message but the true value of no-nonzero in the binary file is 6 (for the test case 3x3 matrix) :
reading matrix in binary from matrix.dat ... ------------------------------------------------------------------------ Petsc Release Version 2.3.1, Patch 13, Wed May 10 11:08:35 CDT 2006 BK revision: balay at asterix.mcs.anl.gov|ChangeSet|20060510160640|13832 See docs/changes/index.html for recent updates. See docs/faq.html for hints about trouble shooting. See docs/index.html for manual pages. ------------------------------------------------------------------------ ./ex31 on a linux named akbaba.ae.metu.edu.tr by evrim Thu Jun 15 09:26:36 2006 Libraries linked from /home/evrim/petsc-2.3.1-p13/lib/linux Configure run at Tue May 30 10:26:48 2006 Configure options --with-scalar-type=complex --with-shared=0 ------------------------------------------------------------------------ [0]PETSC ERROR: MatLoad_SeqAIJ() line 3055 in src/mat/impls/aij/seq/aij.c [0]PETSC ERROR: Read from file failed! [0]PETSC ERROR: Inconsistant matrix data in file. no-nonzeros = 100663296, sum-row-lengths = 234300 ! [0]PETSC ERROR: MatLoad() line 149 in src/mat/utils/matio.c [0]PETSC ERROR: main() line 37 in src/mat/examples/tests/ex31.c I want to send the global matrix at once to Petsc by a written input file (as i'm working on now) or by sending the matrix array from my fortran code and then partition it and solve iteratively. After the solution i also want to get the solution vector back to my fortran code. As i told in the previous mails i tried to send the matrix array to Petsc and used MatSetValues as reading one value at time in a do loop but it took about 2,5 hours to read the global matrix. Additionally i tried to read a row at a time but can not figure out a algorithm for this. Hence i do not prefer to create the matrix again in Petsc by MatSetValues. Aside i figured out that the binary files written in fortran and c are completely different from each other (fortran adds the size of the characters to the beginning and end of each character) so i wrote a c interface code to get the matrix array from the fortran code and write it to a binary file in c format. By this code i avoided from the additional information in the binary file but i still have the endianness problem. I know that i asked so much but since i'm a rookie in parallel programming, c language and library using i really need your comments on my problem. Sorry for this long mail and thanks a lot for your kind effort on guiding me. Thanks EVRIM
