**fem3d_sample_test**,
a FORTRAN90 code which
calls fem3d_sample(), which
can evaluate a finite element function of a 3D argument.

The computer code and data files described and made available on this web page are distributed under the MIT license

fem3d_sample, a FORTRAN90 code which evaluates a function defined on a 3D tetrahedral mesh as part of the finite element method (FEM).

- fem3d_sample_test.sh, runs all the tests.
- fem3d_sample_test.txt, the output file.

**SQ** is FEM data for the function f(x,y,z)=x^2+2*y^2-z^2, on a 5x5x5 grid
of nodes in the cube [0,4]x[0,4]x[0,4], organized into linear tetrahedrons.
The sample data seeks the values of this function on a 4x4x4
evenly spaced grid.

- fem_sq_nodes.txt, defines the FEM nodes.
- fem_sq_elements.txt, defines the FEM elements.
- fem_sq_values.txt, defines the FEM nodal values.
- sample_sq_nodes.txt, defines the sample nodes.
- sample_sq_values.txt, defines the sample nodal values.
- sample_sq_values_exact.txt, the exact values of the function at the sample nodes. This should be compared with the values determined from the FEM function.