CompositeStellib¶

class
beast.physicsmodel.stars.stellib.
CompositeStellib
(osllist, *args, **kwargs)[source]¶ Bases:
beast.physicsmodel.stars.stellib.Stellib
Generates an object from the union of multiple individual libraries
Contructor
Attributes Summary
return a common wavelength sampling to all libraries.
Methods Summary
genQ
(qname, r, **kwargs)Generate a composite value from a previously calculated
genSpectrum
(T0[, g0, Z0, weights])Generate a composite sprectrum
gen_spectral_grid_from_given_points
(pts[, …])Reinterpolate a given stellar spectral library on to an Isochrone grid
get_boundaries
([dlogT, dlogg])Returns the closed boundary polygon around the stellar library with given margins
interp
(T0, g0, Z0, L0[, dT_max, eps, bounds])Interpolation of the T,g grid
interpMany
(T0, g0, Z0, L0[, dT_max, eps, …])run interp on a list of inputs and returns reduced results
which_osl
(xypoints[, dlogT, dlogg])Returns the library indice that contains each point in xypoints
Attributes Documentation

source
¶

wavelength
¶ return a common wavelength sampling to all libraries. This can be used to reinterpolate any spectrum onto a common definition
Methods Documentation

genQ
(qname, r, **kwargs)[source]¶  Generate a composite value from a previously calculated
interpolation Works on 1 desired star or a population of stars
 Parameters
 qname: str
quantity name from self.grid
 r: (osl, r) tuple
osl: is the library index starting from 1. 0 means no coverage. r: is the result from interp call on the corresponding library.
 Returns
 q: float
value (from weighted sum)

genSpectrum
(T0, g0=None, Z0=None, weights=None, **kwargs)[source]¶  Generate a composite sprectrum
Does the interpolation or uses a previously calculated interpolation Works on 1 desired star or a population of stars
 Parameters
 T0: ndarray(float)
log(Teff) to obtain
 g0: ndarray(float)
log(g) to obtain
 Z0: ndarray(float)
metallicity values
 weights: ndarray(float)
individual weights of each star
 **kwargs forwarded to interp(Many)
 Returns
 s: ndarray
an array containing the composite spectrum reinterpolated onto self.wavelength
Note
if T0 and g0 are iterable, it calls interpMany

gen_spectral_grid_from_given_points
(pts, bounds={'dlogT': 0.1, 'dlogg': 0.3})[source]¶ Reinterpolate a given stellar spectral library on to an Isochrone grid
 Parameters
 pts: dict like structure of points
dictionary like or named data structure of points to interpolate at pts must contain: logg surface gravity in logscale logT log of effective temperatures (in Kelvins) logL log of luminosity in Lsun units Z metallicity
 bounds: dict
sensitivity to extrapolation (see
:func: Stellib.get_boundaries
) default: {dlogT:0.1, dlogg:0.3}
 Returns
 g: SpectralGrid
Spectral grid (in memory) containing the requested list of stars and associated spectra

get_boundaries
(dlogT=0.1, dlogg=0.3, **kwargs)[source]¶ Returns the closed boundary polygon around the stellar library with given margins
 Parameters
 s: Stellib
Stellar library object
 dlogT: float
margin in logT
 dlogg: float
margin in logg
 Returns
 b: ndarray[float, ndim=2]
(closed) boundary points: [logg, Teff] (or [Teff, logg] is swap is True)
Note
as computing the boundary could take time, it is saved in the object and only recomputed when parameters are updated

interp
(T0, g0, Z0, L0, dT_max=0.1, eps=1e06, bounds={})[source]¶ Interpolation of the T,g grid
Interpolate on the grid and returns star indices and associated weights, and Z. 3 to 12 stars are returned. It calls _interp_, but reduce the output to the relevant stars.
 Parameters
 T0: double
log(Teff) to obtain
 g0: double
log(g) to obtain
 T: double
log(Teff) of the grid
 g: double
log(g) of the grid
 dT_max: float
If, T2 (resp. T1) is too far from T compared to T1 (resp. T2), i2 (resp. i1) is not used. (see below for namings)
 eps: foat
temperature sensitivity under which points are considered to have the same temperature
 bounds: dict
sensitivity to extrapolation (see
:func: Stellib.get_boundaries
) default: {dlogT:0.1, dlogg:0.3}
 Returns
 (osl, r): tuple
osl: is the library index starting from 1. 0 means no coverage. r: is the result from interp call on the corresponding library. a 3 to 12 star indexes and associated weights

interpMany
(T0, g0, Z0, L0, dT_max=0.1, eps=1e06, weights=None, bounds={}, pool=None, nthreads=1)[source]¶ run interp on a list of inputs and returns reduced results
Interpolation of the T,g grid at Z0 metallicity
Interpolate on the grid and returns star indices and associated weights, and Z. 3 to 12 stars are returned. It calls _interp_, but reduce the output to the relevant stars.
 Parameters
 T0: ndarray(float)
log(Teff) to obtain
 g0: ndarray(float)
log(g) to obtain
 Z0: ndarray(float)
metallicity values
 L0: ndarray(float)
luminosity values
 dT_max: float
If, T2 (resp. T1) is too far from T compared to T1 (resp. T2), i2 (resp. i1) is not used. (see below for namings)
 eps: foat
temperature sensitivity under which points are considered to have the same temperature
 weights: ndarray(float)
luminosity weigths to apply after interpolation
 bounds: dict
sensitivity to extrapolation (see
:func: Stellib.get_boundaries
) default: {dlogT:0.1, dlogg:0.3} pool: Poollike object
specify a multiprocessing pool for parallel processing
 nthreads: int
number of processes to use by default
 Returns
 (osl, r): tuple
osl is the library index starting from 1. 0 means no coverage. r is the result from interp call on the corresponding library. a 3 to 12 star indexes and associated weights

which_osl
(xypoints, dlogT=0.0, dlogg=0.0)[source]¶ Returns the library indice that contains each point in xypoints
 The decision is made from a two step search:
first, each point is checked against the strict boundary of each library (i.e., dlogT = 0, dlogg = 0).
second, if points are not found in strict mode, the boundary is relaxed and a new search is made.
 Each point is associated to the first library matching the above
conditions.
 Parameters
 xypoints: sequence
a sequence of N logg, logT pairs.
 dlogT: float
margin in logT
 dlogg: float
margin in logg
 Returns
 res: ndarray(dtype=int)
 a ndarray, 0 meaning no library covers the point, and 1, … n,
for the nth library
