Time dependent temperature

[jhdark]

Proposed changes

This update would allow users to define temperature using a callable meaning the temperature can be a function of space or time. When a time_dependent temperature function is given, an attribute temperature_time_dependent is then True, which will then update the temperature function at each time step.

Usage:

my_model.temperature = lambda t: 1.0 + t

or

def temperature_function(t):
    return 1.0 + t


my_model.temperature = temperature_function

Types of changes

What types of changes does your code introduce to FESTIM?

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Code refactoring
• Documentation Update (if none of the other choices apply)
• New tests

Checklist

• Black formatted
• Unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Further comments

If this is a relatively large or complex change, kick off the discussion by explaining why you chose the solution you did and what alternatives you considered, etc...

[codecov]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (2af2937) 98.18% compared to head (b92b827) 98.19%.

Additional details and impacted files

@@           Coverage Diff            @@
##           fenicsx     #620   +/-   ##
========================================
  Coverage    98.18%   98.19%           
========================================
  Files           16       16           
  Lines          552      610   +58     
========================================
+ Hits           542      599   +57     
- Misses          10       11    +1     

Files	Coverage Δ
festim/hydrogen_transport_problem.py	99.20% <98.36%> (-0.28%)	⬇️

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[RemDelaporteMathurin]

Looks great. First round of comments to improve things

[RemDelaporteMathurin]

Happy to merge this!