Add a magnitude postOperation to the surfaceFieldValue function object
Functionality to add/problem to solve
Sometimes I don't care whether the output from surfaceFieldValue is negative or positive (like when monitoring the sum of the flux). Currently the only postOperation in surfaceFieldValue that appears to be supported is sqrt. Adding other simple ones like mag could be useful.
Target audience
Anyone who wants the magnitude of the value calculated by surfaceFieldValue
Proposal
Add a mag postOperation to surfaceFieldValue
Funding
I'm not prepared to fund this directly, but my guess is this will be useful to others. It just seems odd that only one postOperation is supported.