Add preliminary attempt at calculating the Stokes parameter for stratification. This currently returns nonsense values because I do not know what the c1 proportionality constant is supposed to be. The rest is OK, though, I think. I added some skeleton code for the test of the new Stokes function (stokes).
Minor change to the docstring to consolidate it slightly.
Add code to export the locations of the probes when reading probes output.
Hack to fix out of array error when calculating the nodes closest to a given profile. So far as I can see, all this does it mean that sometimes the profile will be marginally shorter than it should be.