Kris Cooper

Additional information on the instrument refactor from today's discussion between @KriSun95 and @settwi _(26/10/2023)_: ## Instrument module structure The instrument code has been moved to its own separate module ([here](https://github.com/KriSun95/sunxspex/tree/instrument-refactor/sunxspex/instruments))....

@samaloney thanks so much for taking the time to run through what's been written. These are really good points and I'm glad the discussion is opening up! >It quite difficult...

This has been on my to-do list for a while, I've just never been able to get around to it properly. I _think_ OSPEX does it via altering the response...

@samaloney, I think your idea of `physical-model->albedo-model->SRM` makes more sense to me. I don't like the idea of editing the response any more than we really need to while having...

@ianan @DanRyanIrish ### Hacked fix to get fit working Change [Line 4753](https://github.com/sunpy/sunxspex/blob/master/sunxspex/sunxspex_fitting/fitter.py#L4753) in `sunxspex.sunxspex_fitting.fitter.py` from `_test_e_range = np.arange(1.6, 5.01, 0.04)[:, None]` to `_test_e_range = np.arange(1.6, 15.01, 0.04)[:, None]`. ### Details...

@ianan, you are correct and apologies this quick fix has been held up. I've now opened a PR with this fix applied in #134.

The `spex_hessi_fits2drm.pro` file that @settwi has linked is likely why my error very helpfully reads: `"Apparently spectrum file's SUMFLAG should be one and I don't know what to do otherwise...

Those AI logos don't look the worst actually, especially the design of the second one. I tried that a while ago and just got back swirling messes with the ones...

This PR is looking good. Would it be worth while creating the `extern` module in `fitting_legacy` and moving the RHESSI code there in this PR as well?

@jajmitchell, is it possible to update the image/examples at the top to show the changes since the PR was opened? I'm mainly thinking of showing the `|` changing to `*`.