# -*- coding: utf-8 -*-
"""
@author: jeremy leconte
A module to handle ouputs rebinning and plotting
"""
from __future__ import annotations
from typing import Optional
import astropy.units as u
import h5py
import numpy as np
from exo_k.util.interp import rebin
from exo_k.util.spectral_object import Spectral_object
from exo_k.util.cst import PLANCK, C_LUM
planckovclum = PLANCK * 100. * C_LUM #100 is a conversion factor from cm^-1 to m^-1
[docs]
class Spectrum(Spectral_object):
"""A class defining a Spectrum object to plot and manipulate.
"""
def __init__(self, value = None, wns = None, wnedges = None, input_spectral_unit='cm^-1', spectral_unit='cm^-1',
filename = None, spectral_radiance = False,
from_taurex = False, dataset = 'native_spectrum', **kwargs):
"""Instanciate with a value, bin centers, and bin edges.
Can also load a Taurex spectrum if filename is provided.
Parameters
----------
value: Array
spectrum values
wns: Array
Spectral grid (can be wavenumbers or wavelengths)
wnedges: Array
Bin edges grid (can be wavenumbers or wavelengths)
input_spectral_unit: str
Unit of the input spectral grid
spectral_unit: str
desired output unit for the spectral grid
filename: str
Name of a file where the spectrum is stored.
If a filename is given, there is no need to provide
values, wns, ...
spectral_radiance: bool
If True, the spectrum is assumed to be a flux in units of
inverse spectral units (for example W/micron if the spectral unit is microns)
If False, the spectrum is considered as monochromatic values (like Rp/Rs**2)
"""
super().__init__()
self.value = value
self.wns = wns
self.wnedges = wnedges
self.spec_unit = input_spectral_unit
self.spectral_radiance = spectral_radiance
if filename is not None:
if from_taurex:
self.load_taurex(filename, dataset)
elif filename.lower().endswith(('.hdf5', '.h5')):
self.read_hdf5(filename)
elif filename.lower().endswith(('.dat', '.txt')):
self.read_ascii(filename, **kwargs)
if (self.wnedges is None) and (self.wns is not None):
self.wnedges = np.concatenate(([self.wns[0]],
(self.wns[:-1]+self.wns[1:])*0.5,[self.wns[-1]]))
self.convert_spectral_units(input_spectral_unit=input_spectral_unit,
spectral_unit=spectral_unit, spectral_radiance=spectral_radiance)
if self.wnedges is not None:
self.dwnedges = np.diff(self.wnedges)
else:
self.dwnedges = None
[docs]
def convert_spectral_units(self, input_spectral_unit='cm^-1', spectral_unit='cm^-1',
spectral_radiance: Optional[bool] = None):
if spectral_unit != input_spectral_unit:
wns_tmp = (self.wns*u.Unit(input_spectral_unit)).to(u.Unit(spectral_unit), equivalencies=u.spectral()).value
wnedges_tmp = (self.wnedges*u.Unit(input_spectral_unit)).to(u.Unit(spectral_unit), equivalencies=u.spectral()).value
if spectral_radiance is not None:
self.spectral_radiance = spectral_radiance
if self.spectral_radiance:
dwnedges = np.diff(self.wnedges)
dwnedges_tmp = np.diff(wnedges_tmp)
self.value = self.value * np.abs(dwnedges / dwnedges_tmp)
# assumes that the wavelength unit
# is the same as the spectral unit (for example F in W/nm if wl in nm).
if wnedges_tmp[-1] > wnedges_tmp[0]:
self.wns = wns_tmp
self.wnedges = wnedges_tmp
else:
self.wns = np.copy(wns_tmp[::-1])
self.wnedges = np.copy(wnedges_tmp[::-1])
self.value = np.copy(self.value[::-1])
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def normalize(self, bolometric_flux: float):
"""Normalize the spectrum to a specified bolometric flux
Parameters
----------
bolometric_flux: float
Integral of the flux over the total bandpass after normalization.
"""
factor = bolometric_flux / self.total
self.value *= factor
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def photonize(self):
"""Translate to photon count in each bin
"""
self.value /= self.wns * planckovclum
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def dephotonize(self):
"""Translate back to energy
"""
self.value *= self.wns * planckovclum
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def integrate_per_bin(self):
"""integrate energy in each bin
"""
self.value *= self.dwnedges
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def copy(self):
"""Deep copy of the spectrum.
"""
return Spectrum(self.value.copy(), self.wns.copy(), self.wnedges.copy(),
input_spectral_unit=self.spec_unit, spectral_unit=self.spec_unit)
[docs]
def plot_spectrum(self, ax, per_wavenumber=True, x_axis='wls',
xscale=None, yscale=None, **kwarg):
"""Plot the spectrum
Parameters
----------
ax : :class:`pyplot.Axes`
A pyplot axes instance where to put the plot.
per_wavenumber: bool, optional
Defines the units of spectral flux density.
False converts to per wavelength units.
x_axis: str, optional
If 'wls', x axis is wavelength. Wavenumber otherwise.
xscale, yscale: str, optional
If 'log' log axes are used.
"""
if per_wavenumber:
toplot=self.value
else:
toplot=self.value/self.wls**2*1.e4
if x_axis == 'wls':
ax.plot(self.wls,toplot,**kwarg)
ax.set_xlabel('Wavelength (micron)')
else:
ax.plot(self.wns,toplot,**kwarg)
ax.set_xlabel('Wavenumber (cm$^{-1}$)')
ax.set_ylabel('Flux')
if xscale is not None: ax.set_xscale(xscale)
if yscale is not None: ax.set_yscale(yscale)
[docs]
def bin_down(self, wnedges):
"""Bins down the spectrum to a new grid of wnedges by conserving area.
Parameters
----------
wnedges: array, np.ndarray
Wavenumbers of the bin edges to be used
"""
wnedges=np.array(wnedges)
self.value=rebin(self.value,self.wnedges,wnedges)
self.wnedges=wnedges
self.dwnedges = np.diff(self.wnedges)
self.wns=0.5*(self.wnedges[:-1]+self.wnedges[1:])
[docs]
def bin_down_cp(self, wnedges):
"""Returns a new binned down spectrum to a grid of wnedges by conserving area.
Parameters
----------
wnedges: array, np.ndarray
Wavenumbers of the bin edges to be used
Returns
-------
:class:`Spectrum`
Binned down spectrum
"""
res=self.copy()
res.bin_down(wnedges)
return res
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def clip_spectral_range(self, wn_range=None, wl_range=None):
"""Limits the data to the provided spectral range (inplace):
* Wavenumber in cm^-1 if using wn_range argument
* Wavelength in micron if using wl_range
"""
iw_min, iw_max = self.select_spectral_range(wn_range, wl_range)
self.value = self.value[iw_min:iw_max]
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def randomize(self, uncertainty = 0.):
"""Adds random noise with a given uncertainty.
"""
self.noise = uncertainty * np.random.randn((self.value.size))
self.value += self.noise
def __add__(self, other):
"""Defines addition
"""
if isinstance(other, (float, int, np.ndarray)):
return Spectrum(self.value + other, self.wns, self.wnedges)
if (self.wns.size == other.wns.size) and np.array_equal(self.wns, other.wns):
val = self.value + other.value
return Spectrum(val, self.wns, self.wnedges)
else:
raise RuntimeError('The two spectra do not have the same spectral sampling.')
def __radd__(self, other):
"""Use commutativity v + S == S + v"""
return self.__add__(other)
def __sub__(self, other):
"""Defines subtraction
"""
if isinstance(other, (float, int, np.ndarray)):
return Spectrum(self.value - other, self.wns, self.wnedges)
if (self.wns.size == other.wns.size) and np.array_equal(self.wns, other.wns):
val = self.value - other.value
return Spectrum(val, self.wns, self.wnedges)
else:
raise RuntimeError('The two spectra do not have the same spectral sampling.')
def __mul__(self, other):
"""Defines multiplication
"""
if isinstance(other, (float, int, np.ndarray)):
return Spectrum(self.value * other, self.wns, self.wnedges)
if (self.wns.size == other.wns.size) and np.array_equal(self.wns, other.wns):
val = self.value * other.value
return Spectrum(val, self.wns, self.wnedges)
else:
raise RuntimeError('The two spectra do not have the same spectral sampling.')
def __rmul__(self, other):
"""Use commutativity v * S == S * v"""
return self.__mul__(other)
def __truediv__(self, other):
"""Defines division
"""
if isinstance(other, (float, int, np.ndarray)):
return Spectrum(self.value / other, self.wns, self.wnedges)
if (self.wns.size == other.wns.size) and np.array_equal(self.wns, other.wns):
val = self.value / other.value
return Spectrum(val, self.wns, self.wnedges)
else:
raise RuntimeError('The two spectra do not have the same spectral sampling.')
def __rtruediv__(self, other):
"""Defines division
"""
if isinstance(other, (float, int, np.ndarray)):
return Spectrum(other / self.value, self.wns, self.wnedges)
if (self.wns.size == other.wns.size) and np.array_equal(self.wns, other.wns):
val = other.value / self.value
return Spectrum(val, self.wns, self.wnedges)
else:
raise RuntimeError('The two spectra do not have the same spectral sampling.')
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def std(self):
"""Defines standard deviation
"""
return self.value.std()
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def abs(self):
"""Defines absolute value
"""
return Spectrum(np.abs(self.value),self.wns,self.wnedges)
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def log10(self):
"""Defines Log 10
"""
return Spectrum(np.log10(self.value),self.wns,self.wnedges)
@property
def total(self):
"""Defines the weighted sum over the spectrum
"""
return np.dot(self.value,self.dwnedges)
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def read_hdf5(self, filename=None):
"""Reads data in a hdf5 file
Parameters
----------
filename: str
Name of the file to be created and saved
"""
if (filename is None or not filename.lower().endswith(('.hdf5', '.h5'))):
raise RuntimeError("You should provide an input hdf5 file")
with h5py.File(filename, 'r') as f:
self.wns=f['bin_centers'][...]
self.wnedges=f['bin_edges'][...]
if 'units' in f['bin_edges'].attrs:
self.spec_unit=f['bin_edges'].attrs['units']
else:
if 'units' in f['bin_centers'].attrs:
self.spec_unit=f['bin_centers'].attrs['units']
self.value=f['spectrum'][...]
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def write_hdf5(self, filename):
"""Saves data in a hdf5 format
Parameters
----------
filename: str
Name of the file to be created and saved
"""
fullfilename=filename
if not filename.lower().endswith(('.hdf5', '.h5')):
fullfilename=filename+'.h5'
compression="gzip"
with h5py.File(fullfilename, 'w') as f:
f.create_dataset("spectrum", data=self.value, compression=compression)
f.create_dataset("bin_edges", data=self.wnedges, compression=compression)
f["bin_edges"].attrs["units"] = 'cm^-1'
f.create_dataset("bin_centers", data=self.wns, compression=compression)
f["bin_centers"].attrs["units"] = 'cm^-1'
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def read_ascii(self, filename, usecols = (0,1), skip_header=0):
"""Saves data in a ascii format
Parameters
----------
filename: str
Name of the file to be read
spec_axis: str
Whether the spectral axis in the file is
wavenumber in cm^-1 ('wns') or wavelength in microns ('wls')
skip_header: int
Number of lines to skip
"""
raw=np.genfromtxt(filename, skip_header = skip_header,
usecols = usecols, names=('spec_axis','value'))
self.wns = raw['spec_axis']
self.value = raw['value']
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def write_ascii(self, filename, fmt='%.18e', spec_axis='wns', header=None):
"""Saves data in a ascii format
Parameters
----------
filename: str
Name of the file to be created and saved
"""
fullfilename=filename
if not filename.lower().endswith(('.dat', '.txt')):
fullfilename=filename+'.dat'
head=header
if spec_axis=='wns':
if head is None: head='wavenumber(cm^-1) spectrum'
np.savetxt(fullfilename, np.array([self.wns,self.value]).transpose(),
fmt=fmt, header=head)
else:
if head is None: head='wavelength(micron) spectrum'
np.savetxt(fullfilename, np.array([self.wls[::-1],self.value[::-1]]).transpose(),
fmt=fmt, header=head)
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def load_taurex(self, filename,dataset='native_spectrum'):
"""Loads a taurex file
Parameters
----------
filename: str
Full name (path) of the hdf5 file to load
dataset: str
Name of the hdf5 dataset to load
"""
with h5py.File(filename, 'r') as f:
self.wns = f['Output/Spectra/native_wngrid'][...]
self.value = f['Output/Spectra/'+dataset][...]
self.wnedges=np.concatenate(([self.wns[0]],(self.wns[:-1]+self.wns[1:])*0.5,[self.wns[-1]]))
def __repr__(self):
"""Method to output header
"""
output="""
value : {val}
wl (microns) : {wl}
""".format(val=self.value,wl=self.wls)
return output