# Guide

The `FinEtools`

package is used here to solve a variety of finite element problems. This package can provide an overlay to parallelize sparse matrix assembly.

There is one high-level function that can be used to parallelize the assembly of any sparse matrix – acoustic mass or stiffness, conductivity matrix, stiffness or mass matrix, etc.

This bit of code will assemble the diffusion bilinear form sparse matrix stored in the CSR format:

```
function createsubdomain(fessubset)
FEMMBase(IntegDomain(fessubset, GaussRule(3, 2)))
end
function matrixcomputation!(femm, assblr)
bilform_diffusion(femm, assblr, geom, psi, DataCache(Matrix(1.0 * LinearAlgebra.I(3))))
end
K1 = parallel_make_matrix(fes, psi, createsubdomain, matrixcomputation!;
ntasks=ntasks, kind=:CSR)
```

The user can ask for any number of tasks to be used (even though it would be best to match it to the number of available threads).