Make conversion to theta optional in spice?

[bradyrx]

I'm thinking that the conversion from T to theta in spice should be an optional feature. I imagine it is assumed for observational data that T is in situ T. However, a lot of model output comes out as theta (potential temperature).

Maybe it would be good to add theta=False at the end, then for the following lines, wrap with if not theta:

python-oceans/oceans/sw_extras/sw_extras.py

Lines 546 to 547 in 591e85d

	# FIXME: I'm not sure about this next step.
	pt = sw.ptmp(s, t, p)

Also this must be referencing an old version of seawater. sw.ptmp doesn't exist now. I believe it's now temppot.

I'm happy to implement all this if it makes sense and this package is still actively developed.

[ocefpaf]

Sure. A PR would be most welcomed! Note that we use the python-seawater and it is still ptmp. There has been no updates as far as I know b/c that is deprecated. (We should all be using gsw's TEOS-10 now;-p)