Dynamic allocation of Non zeros?

[Zhifeng Sheng]

Dear all

It is always not easy to determine the number of nonzeros in a row 
without any cost.

I wonder if I can make dynamic allocation, for instance, if one found 
the nonzeros of a row overflow the pre-allocated space, then the space 
shall be doubled.

This may waste some memory but it may not be that bad. Or maybe this is 
already done in Petsc?

Could please tell what happens if I assign the nozero number in rows to 
be zeros and let the programme fills in the nonzeros ?

Best regards
Zhifeng Sheng