[petsc-users] Obtain the precondioned matrix

[我]

Hi all,
I want to analyze the preconditioned matrix. But the KSPComputeExplicitOperator 
costs too much time to obtain the matrix. My origin matrix is about 3000*3000 
sparse one. I noticed this function is applicable for the relative small 
system. What's the matrix-size limitation for this function? And for my case, 
any suggestions to solve it with less time?
Thank you very much!
daye