# Matrix Operations (Mat)
PETSc matrices (`Mat` objects) are used to store Jacobians and other sparse matrices
in PDE-based (or other) simulations. Users guide chapter: [](ch_matrices). See also [](../MatGraphOperations/index).
Examples
Source files
fdmpiaij.c
mpb_aij.c
mpiaijpc.c
mpimattransposematmult.c
mmaij.c
mpiaij.h
mpihashmat.h
mpimatmatmatmult.c
mpiov.c
mpiptap.c
mpiaij.c
mpimatmatmult.c
Directories
crl
mkl_cpardiso
mpicusparse
mpiviennacl
mumps
pastix
superlu_dist
aijmkl
aijperm
aijsell
mpiviennaclcuda
strumpack
kokkos
mpihipsparse