[petsc-users] Question on non-zero pattern

[Sanjay Govindjee]

Is there a mechanism for resetting a matrix's non-zero pattern?

In particular,  I have a preallocated a matrix, set the values, and 
assembled it.
And used it to solve a problem.

Now I would like to zero it, and reassemble it with a different non-zero 
pattern.
Note the matrix has been preallocated so that it can accommodate both 
non-zero
patterns.

-sanjay