tolerance for diagonal entries + Slepc

Umut Tabak u.tabak at tudelft.nl
Mon Aug 3 12:04:27 CDT 2009


Hong Zhang wrote:
>
> Umut,
>
> The data file Mshell.mm has incorrect nnz = 14865.
> 'wc -l Mshell.mm' displays
>
> 17571 Mshell.mm
> i.e., nnz = 17571 - 2 ( num of lines - 2 header lines)
>
> I add
> if (i == nnz-1) printf("i %d, row %d, col %d\n",i,row,col);
> in line 58 of ex72.c, and get
>
> ./ex72 -fin Mshell.mm -fout mat.out
> %% Matrix Market Real Matrix
> m = 1848, n = 1848, nnz = 14865
> i 14864, row 1553, col 1487
> Reading matrix completes.
>
> As you see, you only read matrix upto row 1553, missing
> many entries.
>
Thanks for the pointers, actually, the matrices are exported from a 
program on a tolerance selection, I guess there is a problem on the 
selection of that tolerance value or the implementation, I did not think 
that the matrix export part could have problems, honestly. So thanks for 
the pointers and debugging help.


More information about the petsc-users mailing list