tolerance for diagonal entries + Slepc

[Hong Zhang]

> Hi Hong,
>
> Thanks for the quick reply, that last part of the matrix in matrix market 
> format, I read this with one of the examples that you can read in the matrix 
> market real format:
> ...
> 1848 925 1.207005667e-06
> 1848 1032 1.545494254e-08
> 1848 1771 1.207005667e-06
> 1848 1777 4.828022669e-06
> 1848 1782 -3.078839811e-08
> 1848 1842 1.545494254e-08
> 1848 1848 6.181977018e-08 // this is source of the issue
> ...
> So actually very close to zero. I have this numerical problem on most of my 
> matrices that I would like to interface with Petsc. The point which made me 
> think this way is that Matlab which uses Arpack to solve eigenvalue problems 
> did not experience any problems to solve the system. In Petsc+Slepc, I ran 
> into this problem(a generalized eigenvalue problem,BTW).

Which code do you use for reading the matrix in matrix market
into petsc? I guess that code needs to be modified.

Hong

>
> Best regards,
> Umut
>
>
>