CompositeStellib

class beast.physicsmodel.stars.stellib.CompositeStellib(osllist, *args, **kwargs)[source]

Bases: Stellib

Generates an object from the union of multiple individual libraries

Contructor

Attributes Summary

source

wavelength

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 – value (from weighted sum)

Return type:

float

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

  • interp(Many) (**kwargs forwarded to)

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 log-scale 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 – Spectral grid (in memory) containing the requested list of stars and associated spectra

Return type:

SpectralGrid

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=1e-06, 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) – 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

Return type:

tuple

interpMany(T0, g0, Z0, L0, dT_max=0.1, eps=1e-06, 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 (Pool-like object) – specify a multiprocessing pool for parallel processing

  • nthreads (int) – number of processes to use by default

Returns:

(osl, r) – 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

Return type:

tuple

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 –

a ndarray, 0 meaning no library covers the point, and 1, … n,

for the n-th library

Return type:

ndarray(dtype=int)