Add multifrequency capabilities for ContinuousImage

[erandichavez]

Here's the multifrequency code! This is the implementation specifically for ContinuousImage models. This should now work with the TaylorSpectral definition in freqtaylor.jl --- I had to add a new function definition for TaylorSpectral to do this, but everything should still work for the multifrequency geometric modeling!

[codecov]

Codecov Report

Attention: Patch coverage is 93.93939% with 4 lines in your changes missing coverage. Please review.

Project coverage is 91.40%. Comparing base (94bb8d5) to head (0d834d8).
Report is 18 commits behind head on main.

Files with missing lines	Patch %	Lines
src/models/multifrequency.jl	93.54%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #76      +/-   ##
==========================================
+ Coverage   91.24%   91.40%   +0.16%     
==========================================
  Files          29       30       +1     
  Lines        1975     2059      +84     
==========================================
+ Hits         1802     1882      +80     
- Misses        173      177       +4     

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

[ptiede]

For the format suggestions, you can fix those by running JuliaFormatter.format(".") in the VLBISkyModels directory.
Just download JuliaFormatter in your global environment first.

[ptiede]

Codecov Report

Attention: Patch coverage is 0% with 64 lines in your changes missing coverage. Please review.

Project coverage is 88.47%. Comparing base (94bb8d5) to head (e77415e).
Report is 9 commits behind head on main.

Files with missing lines Patch % Lines
src/models/multifrequency.jl 0.00% 60 Missing ⚠️
src/models/multidomain/freqtaylor.jl 0.00% 4 Missing ⚠️
Additional details and impacted files
☔ View full report in Codecov by Sentry. 📢 Have feedback on the report? Share it here.

@erandichavez This ensures that the new code functionality is included in unit tests. Tests can be added in the test folder. I think we just want to make sure that intensitymap and visibilitymap work.

[erandichavez]

Just added tests for all the new multifrequency code! It lives in multifrequency.jl - the tests passed on my computer, fingers crossed...

[ptiede]

The tests passed. The error is from some weird issue with the GC that I do not understand.

[ptiede]

Do we need to include VLBIImagePriors as a dep?

[ptiede]

This is just an idea and if this is too much work don't worry about it, but how to do you feel about removing this Multifrequency model and just converting your visibility_numeric to work based on ContinuousImage?
So something like replacing

function visibilitymap_numeric(m::Multifrequency, g::AbstractFourierDualDomain)

with

function visibilitymap_numeric(m::ContinuousImage{<:DomainParams}, g::AbstractFourierDualDomain)

and then using the build_params functionality to construct the image grid. This will break all the script, but it will make the code more "consistent".

[ptiede]

I think the only thing preventing me from merging this is just adding the missing docstrings to the docs.
The logs for the Documentation build note that

┌ Error: 5 docstrings not included in the manual:
│ 
│     VLBISkyModels.build_imagecube :: Tuple{Multifrequency, RectiGrid}
│     VLBISkyModels.applyspectral :: Union{Tuple{N}, Tuple{AbstractArray, TaylorSpectral, N}} where N<:Number
│     VLBISkyModels.AbstractSpectralModel
│     VLBISkyModels.generatemodel :: Union{Tuple{N}, Tuple{Multifrequency, N}} where N<:Number
│     VLBISkyModels.Multifrequency

if you add those to docs/src/api.md that would be enough!

[ptiede]

Oh and removing VLBIImagePriors as a dep since I did confirm we don't need it.