ESBO-ETC/esbo_etc/classes/SpectralQty.py

260 lines
12 KiB
Python

from esbo_etc.lib.helpers import error
from scipy.interpolate import interp1d
import astropy.units as u
import math
from typing import Union
import logging
from astropy.io import ascii
import re
class SpectralQty:
"""
A class to hold and work with spectral quantities
"""
def __init__(self, wl: u.Quantity, qty: u.Quantity, extrapolate: bool = False) -> "SpectralQty":
"""
Initialize a new spectral quantity
Parameters
----------
wl : Quantity
The binned wavelengths
qty : Quantity
The quantity values corresponding to the binned wavelengths. If the values are supplied without a unit,
they are assumed to be dimensionless.
extrapolate : bool
Whether extrapolation should be allowed. If disabled, the spectrum will be truncated and a warning given.
Returns
-------
sqty : SpectralQty
The created spectral quantity.
"""
# Check if both lengths are equal
if len(wl) == len(qty):
# check if units are given. If not, add a dimensionless unit
if hasattr(wl, "unit"):
self.wl = wl
else:
self.wl = wl * u.dimensionless_unscaled
if hasattr(qty, "unit"):
self.qty = qty
else:
self.qty = qty * u.dimensionless_unscaled
else:
error("Lengths not matching")
self._extrapolate = extrapolate
@classmethod
def fromFile(cls, file: str, wl_unit_default: u.Quantity = None, qty_unit_default: u.Quantity = None,
extrapolate: bool = False) -> "SpectralQty":
"""
Initialize a new spectral quantity and read the values from a file
Parameters
----------
file : str
Path to the file to read the values from. The file needs to provide two columns: wavelength
and the corresponding spectral quantity. The format of the file will be guessed by
`astropy.io.ascii.read()`. If the file doesn't provide units via astropy's enhanced CSV format, the units
will be read from the column headers or otherwise assumed to be *wl_unit_default* and *qty_unit_default*.
wl_unit_default : Quantity
Default unit to be used for the wavelength column if no units are provided by the file.
qty_unit_default : Quantity
Default unit to be used for the quantity column if no units are provided by the file.
extrapolate : bool
Whether extrapolation should be allowed. If disabled, the spectrum will be truncated and a warning given.
Returns
-------
sqty : SpectralQty
The created spectral quantity.
"""
# Read the file
data = ascii.read(file)
# Check if units are given
if data[data.colnames[0]].unit is None:
# Convert values to float
data[data.colnames[0]] = list(map(float, data[data.colnames[0]]))
data[data.colnames[1]] = list(map(float, data[data.colnames[1]]))
# Check if units are given in column headers
if all([re.search("\\[.+\\]", x) for x in data.colnames]):
# Extract units from headers and apply them on the columns
units = [u.Unit(re.findall("(?<=\\[).+(?=\\])", x)[0]) for x in data.colnames]
data[data.colnames[0]].unit = units[0]
data[data.colnames[1]].unit = units[1]
# Use default units
elif wl_unit_default is not None and qty_unit_default is not None:
data[data.colnames[0]].unit = wl_unit_default
data[data.colnames[1]].unit = qty_unit_default
return cls(data[data.colnames[0]].quantity, data[data.colnames[1]].quantity, extrapolate=extrapolate)
def __eq__(self, other) -> bool:
"""
Check if this object is equal to another object
Parameters
----------
other : SpectralQty
Object to compare with
Returns
-------
res : bool
Result of the comparison
"""
return self.wl.unit == other.wl.unit and self.qty.unit == other.qty.unit and \
len(self.wl) == len(other.wl) and len(self.qty) == len(other.qty) and \
all([math.isclose(x, y, rel_tol=1e-5) for x, y in zip(self.wl.value, other.wl.value)]) and \
all([math.isclose(x, y, rel_tol=1e-5) for x, y in zip(self.qty.value, other.qty.value)])
def __add__(self, other: Union[int, float, u.Quantity, "SpectralQty"]) -> "SpectralQty":
"""
Calculate the sum with another object
Parameters
----------
other : Union[int, float, u.Quantity, "SpectralQty"]
Addend to be added to this object. If the binning of the object on the right hand side differs
from the binning of the left object, the object on the right hand side will be rebinned.
Returns
-------
sum : SpectralQty
The sum of both objects
"""
# Summand is of type int or float, use same unit
if isinstance(other, int) or isinstance(other, float):
return SpectralQty(self.wl, self.qty + other * self.qty.unit)
# Summand is of type Quantity
elif isinstance(other, u.Quantity):
if other.unit == self.qty.unit:
return SpectralQty(self.wl, self.qty + other)
else:
raise TypeError("Units are not matching for addition.")
# Summand is of type SpectralQty
else:
if other.wl.unit.is_equivalent(self.wl.unit) and other.qty.unit.is_equivalent(self.qty.unit):
# Wavelengths are matching, just add the quantities
if len(self.wl) == len(other.wl) and all(self.wl == other.wl):
return SpectralQty(self.wl, self.qty + other.qty)
# Wavelengths are not matching, rebinning needed
else:
# Rebin addend
other_rebinned = other.rebin(self.wl)
if len(self.wl) == len(other_rebinned.wl) and all(self.wl == other_rebinned.wl):
return SpectralQty(self.wl, self.qty + other_rebinned.qty)
else:
# Wavelengths are still not matching as extrapolation is disabled, rebin this spectral quantity
return SpectralQty(other_rebinned.wl, self.rebin(other_rebinned.wl).qty + other_rebinned.qty)
else:
error("Units are not matching for addition.")
__radd__ = __add__
def __sub__(self, other: Union[int, float, u.Quantity, "SpectralQty"]) -> "SpectralQty":
"""
Calculate the difference to another object
Parameters
----------
other : Union[int, float, u.Quantity, "SpectralQty"]
Subtrahend to be subtracted from this object. If the binning of the object on the right hand side differs
from the binning of the left object, the object on the right hand side will be rebinned.
Returns
-------
sum : SpectralQty
The difference of both objects
"""
# Subtrahend is of type int or float, use same unit
if isinstance(other, int) or isinstance(other, float):
return SpectralQty(self.wl, self.qty - other * self.qty.unit)
# Subtrahend is of type Quantity
elif isinstance(other, u.Quantity):
if other.unit == self.qty.unit:
return SpectralQty(self.wl, self.qty - other)
else:
raise TypeError('Units are not matching for subtraction.')
# Subtrahend is of type SpectralQty
else:
if other.wl.unit.is_equivalent(self.wl.unit) and other.qty.unit.is_equivalent(self.qty.unit):
# Wavelengths are matching, just subtract the quantities
if len(self.wl) == len(other.wl) and all(self.wl == other.wl):
return SpectralQty(self.wl, self.qty - other.qty)
# Wavelengths are not matching, rebinning needed
else:
# Rebin subtrahend
other_rebinned = other.rebin(self.wl)
if len(self.wl) == len(other_rebinned.wl) and all(self.wl == other_rebinned.wl):
return SpectralQty(self.wl, self.qty - other_rebinned.qty)
else:
# Wavelengths are still not matching as extrapolation is disabled, rebin this spectral quantity
return SpectralQty(other_rebinned.wl, self.rebin(other_rebinned.wl).qty - other_rebinned.qty)
else:
error("Units are not matching for substraction.")
def __mul__(self, other: Union[int, float, u.Quantity, "SpectralQty"]) -> "SpectralQty":
"""
Calculate the product with another object
Parameters
----------
other : Union[int, float, u.Quantity, "SpectralQty"]
Factor to be multiplied with this object. If the binning of the object on the right hand side differs
from the binning of the left object, the object on the right hand side will be rebinned.
Returns
-------
sum : SpectralQty
The product of both objects
"""
# Factor is of type int, float or Quantity, just multiply
if isinstance(other, int) or isinstance(other, float) or isinstance(other, u.Quantity):
return SpectralQty(self.wl, self.qty * other)
# Factor is of type SpectralQty
else:
if other.wl.unit.is_equivalent(self.wl.unit):
# Wavelengths are matching, just multiply the quantities
if len(self.wl) == len(other.wl) and all(self.wl == other.wl):
return SpectralQty(self.wl, self.qty * other.qty)
# Wavelengths are not matching, rebinning needed
else:
# Rebin factor
other_rebinned = other.rebin(self.wl)
if len(self.wl) == len(other_rebinned.wl) and all(self.wl == other_rebinned.wl):
return SpectralQty(self.wl, self.qty * other_rebinned.qty)
else:
# Wavelengths are still not matching as extrapolation is disabled, rebin this spectral quantity
return SpectralQty(other_rebinned.wl, self.rebin(other_rebinned.wl).qty * other_rebinned.qty)
else:
error("Units are not matching for multiplication.")
__rmul__ = __mul__
def rebin(self, wl: u.Quantity) -> "SpectralQty":
"""
Resample the spectral quantity sqty(wl) over the new grid wl, rebinning if necessary, otherwise interpolates.
Copied from ExoSim (https://github.com/ExoSim/ExoSimPublic).
Parameters
----------
wl : Quantity
new binned wavelengths
Returns
-------
sqty : SpectralQty
The rebinned spectral quantity
"""
if not wl.unit.is_equivalent(self.wl.unit):
error("Mismatching units for rebinning: " + wl.unit + ", " + self.wl.unit)
if not self._extrapolate:
if min(wl) < min(self.wl) or max(wl) > max(self.wl):
logging.warning("Extrapolation disabled, bandwidth will be reduced.")
# Remove new wavelengths where extrapolation would have been necessary
wl = [x.value for x in wl if min(self.wl) <= x <= max(self.wl)] * wl.unit
f = interp1d(self.wl, self.qty.value, fill_value="extrapolate")
return SpectralQty(wl, f(wl.to(self.wl.unit)) * self.qty.unit)