How to use fasthenry program for a geometry file?

hi

if i run fasthenry on a geometry file, it produces a mat file with an impedance matrix. how to get the inductance value between 2 nodes (1 port).
i want o get the mounting inductance of a capacitor on a PCB.
they say fasthenry is for computing inductance. is there at least a c source file which computes actually the inductance?

how to use this program anyway?