BTSettl-CIFIST models error with read_model.py and scipy interpnd

[logan-pearce]

I am trying to use the BTSettl-CIFIST models because they go up to the higher temperatures I need for the stars, and I am encountering an error that seems to be deep within the API that I am not able to solve. It seems that when read_model.py interfaces with scipy interpolate.interpnd, there is an error on reshaping an array. This error has not been a problem with any other models I have tried.
I installed species yesterday, version 0.5.3

I am following the "synthetic photometry" tutorial:

import species
species.SpeciesInit()
database = species.Database()
database.add_model(model='bt-settl-cifist', teff_range=(2000., 7000.))
database.add_filter('SLOAN/SDSS.g')
database.add_filter('SLOAN/SDSS.r')
database.add_filter('SLOAN/SDSS.i')
database.add_filter('SLOAN/SDSS.z')
model_param = {'teff':5400, 'logg':4.0, 'feh':0.5, 'distance': Adistance[0], 'radius':1000}
model_box = read_model.get_model(model_param=model_param, spec_res=200., smooth=True)

Produces the error:
`---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
Input In [10], in <cell line: 1>()
----> 1 model_box = read_model.get_model(model_param=model_param, spec_res=200., smooth=True)

File ~/anaconda3/envs/py39/lib/python3.9/site-packages/typeguard/init.py:1033, in typechecked..wrapper(*args, **kwargs)
1031 memo = _CallMemo(python_func, _localns, args=args, kwargs=kwargs)
1032 check_argument_types(memo)
-> 1033 retval = func(*args, **kwargs)
1034 try:
1035 check_return_type(retval, memo)

File ~/anaconda3/envs/py39/lib/python3.9/site-packages/species/read/read_model.py:747, in ReadModel.get_model(self, model_param, spec_res, wavel_resample, magnitude, smooth)
743 parameters.append(model_param["log_kzz"])
745 # Interpolate the spectrum from the grid
--> 747 flux = self.spectrum_interp(parameters)[0]
749 # Add the radius to the parameter dictionary if the mass if given
751 if "mass" in model_param and "radius" not in model_param:

File ~/anaconda3/envs/py39/lib/python3.9/site-packages/scipy/interpolate/_interpolate.py:2515, in RegularGridInterpolator.call(self, xi, method)
2512 raise ValueError("Method '%s' is not defined" % method)
2514 ndim = len(self.grid)
-> 2515 xi = _ndim_coords_from_arrays(xi, ndim=ndim)
2516 if xi.shape[-1] != len(self.grid):
2517 raise ValueError("The requested sample points xi have dimension "
2518 "%d, but this RegularGridInterpolator has "
2519 "dimension %d" % (xi.shape[1], ndim))

File interpnd.pyx:157, in scipy.interpolate.interpnd._ndim_coords_from_arrays()

File interpnd.pyx:182, in scipy.interpolate.interpnd._ndim_coords_from_arrays()

ValueError: cannot reshape array of size 3 into shape (2)`

[tomasstolker]

Hi @logan-pearce,

Thanks for opening this issue! I think that the problem might be the 'feh' parameter that is included in your model_param dictionary while this isn't a free parameter with the BT-Setll CIFIST grid.

That should have printed a warning and ignored the parameter when interpolating a spectrum, but I see now that the parameter is actually not ignored by species so therefore it runs into the interpolation error. Thanks for pointing this out. I will fix that!

You can use methods such as get_parameters, get_bounds, and get_points from the ReadModel class to check which parameters are required.

I hope this solves the problem but let me know otherwise!

[tomasstolker]

Parameters that are not mandatory are now ignored by ReadModel. See commit fa82915 that will be part of a next release.