[petsc-users] Pointwise max for matrices

[Mathieu MORLIGHEM]

Hello,

I am trying to implement a Flux Correction Transport method for advection equations (e.g. http://www.mathematik.uni-dortmund.de/~kuzmin/linfct.pdf).
One of the steps consists of calculating a matrix D which is such that

d_ij = max{ 0 , -k_ij , -kJi }

where k_ij are the components of a transport operator K.
Is there a way to do that without serializing K, which could be memory intensive.

Thanks a lot for your help
Mathieu