pyphot package

Submodules

pyphot.config module

pyphot.helpers module

pyphot.helpers.STmag_from_flux(v)[source]

Convert to ST magnitude from erg/s/cm2/AA (Flambda)

\[ \begin{align}\begin{aligned}mag = -2.5 \log_{10}(F) - 21.10\\M0 = 21.10 F0 = 3.6307805477010028 10^{-9} erg/s/cm2/AA\end{aligned}\end{align} \]
v: np.ndarray[float, ndim=N], or float

array of fluxes

mag: np.ndarray[float, ndim=N], or float

array of magnitudes

pyphot.helpers.STmag_to_flux(v)[source]

Convert an ST magnitude to erg/s/cm2/AA (Flambda)

\[ \begin{align}\begin{aligned}mag = -2.5 \log_{10}(F) - 21.10\\M0 = 21.10 F0 = 3.6307805477010028 10^{-9} erg/s/cm2/AA\end{aligned}\end{align} \]
v: np.ndarray[float, ndim=N] or float

array of magnitudes

flux: np.ndarray[float, ndim=N], or float

array of fluxes

pyphot.helpers.deprecated(message)[source]

Deprecated warning decorator

pyphot.helpers.extractPhotometry(lamb, spec, flist, absFlux=True, progress=True)[source]

Extract seds from a one single spectrum

lamb: ndarray[float,ndim=1]

wavelength of spec

spec: ndarray[float, ndim=1]

spectrum

flist: list[filter]

list of filter objects

absflux: bool

return SEDs in absolute fluxes if set

progress: bool

show progression if set

cls: ndarray[float, ndim=1]

filters central wavelength

seds: ndarray[float, ndim=1]

integrated sed

pyphot.helpers.extractSEDs(lamb, specs, flist, absFlux=True, progress=True)[source]

Extract seds from a grid

g0: ModelGrid instance

initial spectral grid

flist: sequence(filter)

list of filter object instances

absflux: bool

return SEDs in absolute fluxes if set

progress: bool

show progression if set

cls: ndarray[float, ndim=1]

filters central wavelength

seds: ndarray[float, ndim=1]

integrated sed

grid: Table

SED grid properties table from g0 (g0.grid)

pyphot.helpers.fluxErrTomag(flux, fluxerr)[source]

Return the magnitudes and associated errors from fluxes and flux error values

flux: np.ndarray[float, ndim=1]

array of fluxes

fluxerr: np.ndarray[float, ndim=1]

array of flux errors

mag: np.ndarray[float, ndim=1]

array of magnitudes

err: np.ndarray[float, ndim=1]

array of magnitude errors

pyphot.helpers.fluxToMag(flux)[source]

Return the magnitudes from flux values

flux: np.ndarray[float, ndim=N]

array of fluxes

mag: np.ndarray[float, ndim=N]

array of magnitudes

pyphot.helpers.magErrToFlux(mag, err)[source]

Return the flux and associated errors from magnitude and mag error values

mag: np.ndarray[float, ndim=1]

array of magnitudes

err: np.ndarray[float, ndim=1]

array of magnitude errors

flux: np.ndarray[float, ndim=1]

array of fluxes

fluxerr: np.ndarray[float, ndim=1]

array of flux errors

pyphot.helpers.magToFlux(mag)[source]

Return the flux from magnitude values

mag: np.ndarray[float, ndim=N]

array of magnitudes

flux: np.ndarray[float, ndim=N]

array of fluxes

pyphot.helpers.progress_enumerate(it, *args, **kwargs)[source]

Enumerate over a sequence with progression if requested

show_progress: bool

set to show progress

pyphot.licks module

Lick indices calculations

This package provides function to compute spectral indices

A collection of many common indices is available in licks.dat

The Lick system of spectral line indices is one of the most commonly used methods of determining ages and metallicities of unresolved (integrated light) stellar populations.

The calibration of the Lick/ IDS system is complicated because the original Lick spectra were not flux calibrated, so there are usually systematic effects due to differences in continuum shape. Proper calibration involves observing many of the original Lick/IDS standard stars and deriving offsets to the standard system.

Todo

  • fix units: all must be internally computed in AA, flux are not check for per AA

class pyphot.licks.LickIndex(name, lick, unit='AA')[source]

Bases: object

Define a Lick Index similarily to a Filter object

property band

Unitwise band definition

property blue

Unitwise band definition

classmethod continuum_normalized_region_around_line(wi, fi, blue, red, band=None, degree=1)[source]

cut out and normalize flux around a line

wi: ndarray (nw, )

array of wavelengths in AA

fi: ndarray (N, nw)

array of flux values for different spectra in the series

blue: tuple(2)

selection for blue continuum estimate

red: tuple(2)

selection for red continuum estimate

band: tuple(2), optional

select region in this band only. default is band = (min(blue), max(red))

degree: int

degree of the polynomial fit to the continuum

wnew: ndarray (nw1, )

wavelength of the selection in AA

f: ndarray (N, len(wnew))

normalized flux in the selection region

get(wave, flux, **kwargs)[source]

compute spectral index after continuum subtraction

w: ndarray (nw, )

array of wavelengths in AA

flux: ndarray (N, nw)

array of flux values for different spectra in the series

degree: int (default 1)

degree of the polynomial fit to the continuum

nocheck: bool

set to silently pass on spectral domain mismatch. otherwise raises an error when index is not covered

ew: ndarray (N,)

equivalent width or magnitude array

ValueError: when the spectral coverage wave does not cover the index range

property index_unit
info()[source]

display information about the current Index

property red

Unitwise band definition

to_dict()[source]

return a dictionary of the current index

class pyphot.licks.LickLibrary(fname='/github/workspace/pyphot/libs/licks.dat', comment='#')[source]

Bases: object

Collection of Lick indices

property content
property description

any comment in the input file

find(name, case_sensitive=True)[source]
get_library_content()[source]
pyphot.licks.reduce_resolution(wi, fi, fwhm0=0.55, sigma_floor=0.2)[source]

Adapt the resolution of the spectra to match the lick definitions

Lick definitions have different resolution elements as function of wavelength. These definition are hard-coded in this function

wi: ndarray (n, )

wavelength definition

fi: ndarray (nspec, n) or (n, )

spectra to convert

fwhm0: float

initial broadening in the spectra fi

sigma_floor: float

minimal dispersion to consider

flux_red: ndarray (nspec, n) or (n, )

reduced spectra

pyphot.pbar module

Simple progressbar

This package implement a unique progress bar class that can be used to decorate an iterator, a function or even standalone.

The format of the meter is flexible and can display along with the progress meter, the running time, an eta, and the rate of the iterations.

An example is::

description [———-] k/n 10% [time: 00:00:00, eta: 00:00:00, 2.7 iters/sec]

class pyphot.pbar.Pbar(maxval=None, desc=None, time=True, eta=True, rate=True, length=None, file=None, keep=True, mininterval=0.5, miniters=1, units='iters', **kwargs)[source]

Bases: object

make a progress string in a shape of:

[----------] k/n  10% [time: 00:00:00, eta: 00:00:00, 2.7 iters/sec]
time: bool, optional (default: True)

if set, add the runtime information

eta: bool, optional (default: True)

if set, add an estimated time to completion

rate: bool, optional (default: True)

if set, add the rate information

length: int, optional (default: None)

number of characters showing the progress meter itself if None, the meter will adapt to the buffer width

TODO: make it variable with the buffer length

keep: bool, optional (default: True)

If not set, deletes its traces from screen after completion

file: buffer

the buffer to write into

mininterval: float (default: 0.5)

minimum time in seconds between two updates of the meter

miniters: int, optional (default: 1)

minimum iteration number between two updates of the meter

units: str, optional (default: ‘iters’)

unit of the iteration

build_str_meter(n, total, elapsed)[source]

make a progress string in a shape of:

[----------] k/n  10% [time: 00:00:00, eta: 00:00:00, 2.7 iters/sec]
n: int

number of finished iterations

total: int

total number of iterations, or None

elapsed: int

number of seconds passed since start

txt: str

string representing the meter

decorator(func)[source]

Provide a function decorator allowing for counting calls and rates

static format_interval(t)[source]

make a human readable time interval decomposed into days, hours, minutes and seconds

t: int

interval in seconds

txt: str

string representing the interval (format: <days>d <hrs>:<min>:<sec>)

handle_resize(signum, frame)[source]
iterover(iterable, total=None)[source]

Get an iterable object, and return an iterator which acts exactly like the iterable, but prints a progress meter and updates it every time a value is requested.

iterable: generator or iterable object

object to iter over.

total: int, optional

the number of iterations is assumed to be the length of the iterator. But sometimes the iterable has no associated length or its length is not the actual number of future iterations. In this case, total can be set to define the number of iterations.

gen: generator

pass the values from the initial iterator

print_status(s)[source]

print a status s on the last file line and clean the rest of the line

s: str

message to write

update(n, desc=None, total=None)[source]

Kept for backward compatibility and the decorator feature

n: int

force iteration number n

desc: str

update description string

total: int

update the total number of iterations

pyphot.phot module (deprecated)

use either sandbox or astropy submodules

Photometric package

Defines a Filter class and associated functions to extract photometry.

This also include functions to keep libraries up to date

Note

integrations are done using trapz() Why not Simpsons? Simpsons principle is to take sequence of 3 points to make a quadratic interpolation. Which in the end, when filters have sharp edges, the error due to this “interpolation” are extremely large in comparison to the uncertainties induced by trapeze integration.

class pyphot.phot.Ascii_Library(source)[source]

Bases: pyphot.phot.Library

Interface one or multiple directory or many files as a filter library

>>> lib = Ascii_Library(['ground', 'hst', 'myfilter.csv'])
add_filters(filter_object, fmt='%.6f', **kwargs)[source]

Add a filter to the library permanently

filter_object: Filter object

filter to add

get_library_content()[source]

get the content of the library

load_all_filters(interp=True, lamb=None)[source]

load all filters from the library

load_filters(names, interp=True, lamb=None, filterLib=None)[source]

load a limited set of filters

names: list[str]

normalized names according to filtersLib

interp: bool

reinterpolate the filters over given lambda points

lamb: ndarray[float, ndim=1]

desired wavelength definition of the filter

filterLib: path

path to the filter library hd5 file

filters: list[filter]

list of filter objects

class pyphot.phot.Constants[source]

Bases: object

A namespace for constants

c = <Quantity(2.99792458e+18, 'angstrom / second')>
h = <Quantity(6.62607554e-27, 'erg * second')>
class pyphot.phot.Filter(wavelength, transmit, name='', dtype='photon', unit=None)[source]

Bases: object

Class filter

Define a filter by its name, wavelength and transmission The type of detector (energy or photon counter) can be specified for adapting calculations. (default: photon)

name: str

name of the filter

cl: float

central wavelength of the filter

norm: float

normalization factor of the filter

lpivot: float

pivot wavelength of the filter

wavelength: ndarray

wavelength sequence defining the filter transmission curve

transmit: ndarray

transmission curve of the filter

dtype: str

detector type, either “photon” or “energy” counter

unit: str

wavelength units

property AB_zero_Jy

AB flux zero point in Jansky (Jy)

property AB_zero_flux

AB flux zero point in erg/s/cm2/AA

property AB_zero_mag

AB magnitude zero point ABmag = -2.5 * log10(f_nu) - 48.60

= -2.5 * log10(f_lamb) - 2.5 * log10(lpivot ** 2 / c) - 48.60 = -2.5 * log10(f_lamb) - zpts

property ST_zero_Jy

ST flux zero point in Jansky (Jy)

property ST_zero_flux

ST flux zero point in erg/s/cm2/AA

property ST_zero_mag

ST magnitude zero point STmag = -2.5 * log10(f_lamb) -21.1

property Vega_zero_Jy

Vega flux zero point in Jansky (Jy)

property Vega_zero_flux

Vega flux zero point in erg/s/cm2/AA

property Vega_zero_mag

vega magnitude zero point vegamag = -2.5 * log10(f_lamb) + 2.5 * log10(f_vega) vegamag = -2.5 * log10(f_lamb) - zpts

property Vega_zero_photons

Vega number of photons per wavelength unit

Note

see self.get_Nphotons

applyTo(slamb, sflux)[source]

For compatibility but bad name

apply_transmission(slamb, sflux)[source]

Apply filter transmission to a spectrum (with reinterpolation of the filter)

slamb: ndarray

spectrum wavelength definition domain

sflux: ndarray

associated flux

flux: float

new spectrum values accounting for the filter

property cl

Unitwise wavelength definition

classmethod from_ascii(fname, dtype='csv', **kwargs)[source]

Load filter from ascii file

property fwhm

the difference between the two wavelengths for which filter transmission is half maximum

..note::

This calculation is not exact but rounded to the nearest passband data points

getFlux(slamb, sflux, axis=-1)[source]

Integrate the flux within the filter and return the integrated energy If you consider applying the filter to many spectra, you might want to consider extractSEDs.

slamb: ndarray(dtype=float, ndim=1)

spectrum wavelength definition domain

sflux: ndarray(dtype=float, ndim=1)

associated flux

flux: float

Energy of the spectrum within the filter

get_Nphotons(slamb, sflux, axis=-1)[source]

getNphot the number of photons through the filter (Ntot / width in the documentation)

getflux() * leff / hc

slamb: ndarray(dtype=float, ndim=1)

spectrum wavelength definition domain

sflux: ndarray(dtype=float, ndim=1)

associated flux in erg/s/cm2/AA

N: float

Number of photons of the spectrum within the filter

get_flux(slamb, sflux, axis=-1)[source]

getFlux Integrate the flux within the filter and return the integrated energy If you consider applying the filter to many spectra, you might want to consider extractSEDs.

slamb: ndarray(dtype=float, ndim=1)

spectrum wavelength definition domain

sflux: ndarray(dtype=float, ndim=1)

associated flux

flux: float

Energy of the spectrum within the filter

info(show_zeropoints=True)[source]

display information about the current filter

property leff

Unitwise Effective wavelength leff = int (lamb * T * Vega dlamb) / int(T * Vega dlamb)

property lmax

Calculated as the last value with a transmission at least 1% of maximum transmission

property lmin

Calculate das the first value with a transmission at least 1% of maximum transmission

property lphot

Photon distribution based effective wavelength. Defined as

lphot = int(lamb ** 2 * T * Vega dlamb) / int(lamb * T * Vega dlamb)

which we calculate as

lphot = get_flux(lamb * vega) / get_flux(vega)

property lpivot

Unitwise wavelength definition

classmethod make_integration_filter(lmin, lmax, name='', dtype='photon', unit=None)[source]

Generate an heavyside filter between lmin and lmax

reinterp(lamb)[source]

reinterpolate filter onto a different wavelength definition

set_dtype(dtype)[source]

Set the detector type (photon or energy)

set_wavelength_unit(unit)[source]

Set the wavelength units

to_Table(**kwargs)[source]

Export filter to a SimpleTable object

fname: str

filename

Uses SimpleTable parameters

to_dict()[source]

Return a dictionary of the filter

property wavelength

Unitwise wavelength definition

property width

Effective width Equivalent to the horizontal size of a rectangle with height equal to maximum transmission and with the same area that the one covered by the filter transmission curve.

W = int(T dlamb) / max(T)

write_to(fname, **kwargs)[source]

Export filter to a file

fname: str

filename

Uses SimpleTable.write parameters

class pyphot.phot.HDF_Library(source='/github/workspace/pyphot/libs/new_filters.hd5', mode='r')[source]

Bases: pyphot.phot.Library

Storage based on HDF

add_filter(f, **kwargs)[source]

Add a filter to the library permanently

f: Filter object

filter to add

get_library_content()[source]

get the content of the library

load_all_filters(interp=True, lamb=None)[source]

load all filters from the library

interp: bool

reinterpolate the filters over given lambda points

lamb: ndarray[float, ndim=1]

desired wavelength definition of the filter

filters: list[filter]

list of filter objects

load_filters(names, interp=True, lamb=None, filterLib=None)[source]

load a limited set of filters

names: list[str]

normalized names according to filtersLib

interp: bool

reinterpolate the filters over given lambda points

lamb: ndarray[float, ndim=1]

desired wavelength definition of the filter

filterLib: path

path to the filter library hd5 file

filters: list[filter]

list of filter objects

class pyphot.phot.Library(source='/github/workspace/pyphot/libs/new_filters.hd5', *args, **kwargs)[source]

Bases: object

Common grounds for filter libraries

add_filter(f)[source]

add a filter to the library

property content

Get the content list

find(name, case_sensitive=True)[source]
classmethod from_ascii(filename, **kwargs)[source]
classmethod from_hd5(filename, **kwargs)[source]
get_library_content()[source]

get the content of the library

load_all_filters(interp=True, lamb=None)[source]

load all filters from the library

to_csv(directory='./', progress=True, **kwargs)[source]

Export each filter into a csv file with its own name Parameters ———- directory: str

directory to write into

progress: bool

show progress if set

to_hdf(fname='filters.hd5', progress=True, **kwargs)[source]

Export each filter into a csv file with its own name Parameters ———- directory: str

directory to write into

progress: bool

show progress if set

class pyphot.phot.UncertainFilter(wavelength, mean_transmit, samples, name='', dtype='photon', unit=None)[source]

Bases: pyphot.phot.Filter

What could be a filter with uncertainties

wavelength: ndarray

wavelength sequence defining the filter transmission curve

mean_: Filter

mean passband transmission

samples_: sequence(Filter)

samples from the uncertain passband transmission model

name: string

name of the passband

dtype: str

detector type, either “photon” or “energy” counter

unit: str

wavelength units

property AB_zero_Jy

AB flux zero point in Jansky (Jy)

property AB_zero_flux

AB flux zero point in erg/s/cm2/AA

property AB_zero_mag

AB magnitude zero point ABmag = -2.5 * log10(f_nu) - 48.60

= -2.5 * log10(f_lamb) - 2.5 * log10(lpivot ** 2 / c) - 48.60 = -2.5 * log10(f_lamb) - zpts

property ST_zero_Jy

ST flux zero point in Jansky (Jy)

property ST_zero_flux

ST flux zero point in erg/s/cm2/AA

property ST_zero_mag

ST magnitude zero point STmag = -2.5 * log10(f_lamb) -21.1

property Vega_zero_Jy

Vega flux zero point in Jansky (Jy)

property Vega_zero_flux

Vega flux zero point in erg/s/cm2/AA

property Vega_zero_mag

Vega magnitude zero point Vegamag = -2.5 * log10(f_lamb) + 2.5 * log10(f_vega) Vegamag = -2.5 * log10(f_lamb) - zpts

property Vega_zero_photons

Vega number of photons per wavelength unit

Note

see self.get_Nphotons

apply_transmission(slamb, sflux)[source]

Apply filter transmission to a spectrum (with reinterpolation of the filter)

slamb: ndarray

spectrum wavelength definition domain

sflux: ndarray

associated flux

flux: float

new spectrum values accounting for the filter

property cl

Unitwise wavelength definition

classmethod from_ascii(fname, dtype='csv', **kwargs)[source]

Load filter from ascii file

classmethod from_gp_model(model, xprime=None, n_samples=10, **kwargs)[source]

Generate a filter object from a sklearn GP model

model: sklearn.gaussian_process.GaussianProcessRegressor

model of the passband

xprime: ndarray

wavelength to express the model in addition to the training points

n_samples: int

number of samples to generate from the model.

**kwawrgs: dict

UncertainFilter keywords

property fwhm

the difference between the two wavelengths for which filter transmission is half maximum

..note::

This calculation is not exact but rounded to the nearest passband data points

getFlux(slamb, sflux, axis=-1)[source]

Integrate the flux within the filter and return the integrated energy If you consider applying the filter to many spectra, you might want to consider extractSEDs.

slamb: ndarray(dtype=float, ndim=1)

spectrum wavelength definition domain

sflux: ndarray(dtype=float, ndim=1)

associated flux

flux: float

Energy of the spectrum within the filter

get_Nphotons(slamb, sflux, axis=-1)[source]

getNphot the number of photons through the filter (Ntot / width in the documentation)

getflux() * leff / hc

slamb: ndarray(dtype=float, ndim=1)

spectrum wavelength definition domain

sflux: ndarray(dtype=float, ndim=1)

associated flux in erg/s/cm2/AA

N: float

Number of photons of the spectrum within the filter

info(show_zeropoints=True)[source]

display information about the current filter

property leff

Unitwise Effective wavelength leff = int (lamb * T * Vega dlamb) / int(T * Vega dlamb)

property lmax

Calculated as the last value with a transmission at least 1% of maximum transmission

property lmin

Calculate das the first value with a transmission at least 1% of maximum transmission

property lphot

Photon distribution based effective wavelength. Defined as

lphot = int(lamb ** 2 * T * Vega dlamb) / int(lamb * T * Vega dlamb)

which we calculate as

lphot = get_flux(lamb * vega) / get_flux(vega)

property lpivot

Unitwise wavelength definition

reinterp(lamb)[source]

reinterpolate filter onto a different wavelength definition

set_dtype(dtype)[source]

Set the detector type (photon or energy)

set_wavelength_unit(unit)[source]

Set the wavelength units

to_Table(**kwargs)[source]

Export filter to a SimpleTable object

fname: str

filename

Uses SimpleTable parameters

property transmit

Transmission curves

property wavelength

Unitwise wavelength definition

property wavelength_unit

Unit wavelength definition

property width

Effective width Equivalent to the horizontal size of a rectangle with height equal to maximum transmission and with the same area that the one covered by the filter transmission curve.

W = int(T dlamb) / max(T)

pyphot.phot.get_library(fname='/github/workspace/pyphot/libs/new_filters.hd5', **kwargs)[source]

Finds the appropriate class to load the library

class pyphot.phot.set_method_default_units(wavelength_unit, flux_unit, output_unit=None)[source]

Bases: object

Decorator for classmethods that makes sure that the inputs of slamb, sflux are in given units

expects the decorated method to be defined as

>> def methodname(self, lamb, flux)

classmethod force_units(value, unit)[source]

pyphot.sandbox module

Sandbox of new developments

Use at your own risks

Photometric package using Astropy Units

Defines a Filter class and associated functions to extract photometry.

This also include functions to keep libraries up to date

Note

integrations are done using trapz() Why not Simpsons? Simpsons principle is to take sequence of 3 points to make a quadratic interpolation. Which in the end, when filters have sharp edges, the error due to this “interpolation” are extremely large in comparison to the uncertainties induced by trapeze integration.

class pyphot.sandbox.Constants[source]

Bases: object

A namespace for constants

c = <Quantity(2.99792458e+18, 'angstrom / second')>
h = <Quantity(6.62607554e-27, 'erg * second')>
class pyphot.sandbox.UncertainFilter(wavelength, mean_transmit, samples, name='', dtype='photon', unit=None)[source]

Bases: pyphot.sandbox.UnitFilter

What could be a filter with uncertainties

wavelength: ndarray

wavelength sequence defining the filter transmission curve

mean_: Filter

mean passband transmission

samples_: sequence(Filter)

samples from the uncertain passband transmission model

name: string

name of the passband

dtype: str

detector type, either “photon” or “energy” counter

unit: str

wavelength units

property AB_zero_Jy

AB flux zero point in Jansky (Jy)

property AB_zero_flux

AB flux zero point in erg/s/cm2/AA

property AB_zero_mag

AB magnitude zero point ABmag = -2.5 * log10(f_nu) - 48.60

= -2.5 * log10(f_lamb) - 2.5 * log10(lpivot ** 2 / c) - 48.60 = -2.5 * log10(f_lamb) - zpts

property ST_zero_Jy

ST flux zero point in Jansky (Jy)

property ST_zero_flux

ST flux zero point in erg/s/cm2/AA

property ST_zero_mag

ST magnitude zero point STmag = -2.5 * log10(f_lamb) -21.1

property Vega_zero_Jy

Vega flux zero point in Jansky (Jy)

property Vega_zero_flux

Vega flux zero point in erg/s/cm2/AA

property Vega_zero_mag

Vega magnitude zero point Vegamag = -2.5 * log10(f_lamb) + 2.5 * log10(f_vega) Vegamag = -2.5 * log10(f_lamb) - zpts

property Vega_zero_photons

Vega number of photons per wavelength unit

Note

see self.get_Nphotons

apply_transmission(slamb, sflux)[source]

Apply filter transmission to a spectrum (with reinterpolation of the filter)

slamb: ndarray

spectrum wavelength definition domain

sflux: ndarray

associated flux

flux: float

new spectrum values accounting for the filter

property cl

Unitwise wavelength definition

classmethod from_ascii(fname, dtype='csv', **kwargs)[source]

Load filter from ascii file

classmethod from_gp_model(model, xprime=None, n_samples=10, **kwargs)[source]

Generate a filter object from a sklearn GP model

model: sklearn.gaussian_process.GaussianProcessRegressor

model of the passband

xprime: ndarray

wavelength to express the model in addition to the training points

n_samples: int

number of samples to generate from the model.

**kwawrgs: dict

UncertainFilter keywords

property fwhm

the difference between the two wavelengths for which filter transmission is half maximum

..note::

This calculation is not exact but rounded to the nearest passband data points

getFlux(slamb, sflux, axis=-1)[source]

Integrate the flux within the filter and return the integrated energy If you consider applying the filter to many spectra, you might want to consider extractSEDs.

slamb: ndarray(dtype=float, ndim=1)

spectrum wavelength definition domain

sflux: ndarray(dtype=float, ndim=1)

associated flux

flux: float

Energy of the spectrum within the filter

get_Nphotons(slamb, sflux, axis=-1)[source]

getNphot the number of photons through the filter (Ntot / width in the documentation)

getflux() * leff / hc

slamb: ndarray(dtype=float, ndim=1)

spectrum wavelength definition domain

sflux: ndarray(dtype=float, ndim=1)

associated flux in erg/s/cm2/AA

N: float

Number of photons of the spectrum within the filter

info(show_zeropoints=True)[source]

display information about the current filter

property leff

Unitwise Effective wavelength leff = int (lamb * T * Vega dlamb) / int(T * Vega dlamb)

property lmax

Calculated as the last value with a transmission at least 1% of maximum transmission

property lmin

Calculate das the first value with a transmission at least 1% of maximum transmission

property lphot

Photon distribution based effective wavelength. Defined as

lphot = int(lamb ** 2 * T * Vega dlamb) / int(lamb * T * Vega dlamb)

which we calculate as

lphot = get_flux(lamb * vega) / get_flux(vega)

property lpivot

Unitwise wavelength definition

reinterp(lamb)[source]

reinterpolate filter onto a different wavelength definition

set_dtype(dtype)[source]

Set the detector type (photon or energy)

set_wavelength_unit(unit)[source]

Set the wavelength units

to_Table(**kwargs)[source]

Export filter to a SimpleTable object

fname: str

filename

Uses SimpleTable parameters

property transmit

Transmission curves

property wavelength

Unitwise wavelength definition

property wavelength_unit

Unit wavelength definition

property width

Effective width Equivalent to the horizontal size of a rectangle with height equal to maximum transmission and with the same area that the one covered by the filter transmission curve.

W = int(T dlamb) / max(T)

class pyphot.sandbox.UnitAscii_Library(source)[source]

Bases: pyphot.sandbox.UnitLibrary

Interface one or multiple directory or many files as a filter library

>>> lib = Ascii_Library(['ground', 'hst', 'myfilter.csv'])
add_filters(filter_object, fmt='%.6f', **kwargs)[source]

Add a filter to the library permanently

filter_object: Filter object

filter to add

get_library_content()[source]

get the content of the library

load_all_filters(interp=True, lamb=None)[source]

load all filters from the library

load_filters(names, interp=True, lamb=None, filterLib=None)[source]

load a limited set of filters

names: list[str]

normalized names according to filtersLib

interp: bool

reinterpolate the filters over given lambda points

lamb: ndarray[float, ndim=1]

desired wavelength definition of the filter

filterLib: path

path to the filter library hd5 file

filters: list[filter]

list of filter objects

class pyphot.sandbox.UnitFilter(wavelength, transmit, name='', dtype='photon', unit=None)[source]

Bases: object

Evolution of Filter that makes sure the input spectra and output fluxes have units to avoid mis-interpretation.

Note the usual (non SI) units of flux definitions:

flam = erg/s/cm**2/AA fnu = erg/s/cm**2/Hz photflam = photon/s/cm**2/AA photnu = photon/s/cm**2/Hz

Define a filter by its name, wavelength and transmission The type of detector (energy or photon counter) can be specified for adapting calculations. (default: photon)

name: str

name of the filter

cl: float

central wavelength of the filter

norm: float

normalization factor of the filter

lpivot: float

pivot wavelength of the filter

wavelength: ndarray

wavelength sequence defining the filter transmission curve

transmit: ndarray

transmission curve of the filter

dtype: str

detector type, either “photon” or “energy” counter

unit: str

wavelength units

property AB_zero_Jy

AB flux zero point in Jansky (Jy)

property AB_zero_flux

AB flux zero point in erg/s/cm2/AA

property AB_zero_mag

AB magnitude zero point ABmag = -2.5 * log10(f_nu) - 48.60

= -2.5 * log10(f_lamb) - 2.5 * log10(lpivot ** 2 / c) - 48.60 = -2.5 * log10(f_lamb) - zpts

property ST_zero_Jy

ST flux zero point in Jansky (Jy)

property ST_zero_flux

ST flux zero point in erg/s/cm2/AA

property ST_zero_mag

ST magnitude zero point STmag = -2.5 * log10(f_lamb) -21.1

property Vega_zero_Jy

Vega flux zero point in Jansky (Jy)

property Vega_zero_flux

Vega flux zero point in erg/s/cm2/AA

property Vega_zero_mag

vega magnitude zero point vegamag = -2.5 * log10(f_lamb) + 2.5 * log10(f_vega) vegamag = -2.5 * log10(f_lamb) - zpts

property Vega_zero_photons

Vega number of photons per wavelength unit

Note

see self.get_Nphotons

applyTo(slamb, sflux)[source]

For compatibility but bad name

apply_transmission(slamb, sflux)[source]

Apply filter transmission to a spectrum (with reinterpolation of the filter)

slamb: ndarray

spectrum wavelength definition domain

sflux: ndarray

associated flux

flux: float

new spectrum values accounting for the filter

property cl

Unitwise wavelength definition

classmethod from_ascii(fname, dtype='csv', **kwargs)[source]

Load filter from ascii file

property fwhm

the difference between the two wavelengths for which filter transmission is half maximum

..note::

This calculation is not exact but rounded to the nearest passband data points

getFlux(slamb, sflux, axis=-1)[source]

Integrate the flux within the filter and return the integrated energy If you consider applying the filter to many spectra, you might want to consider extractSEDs.

slamb: ndarray(dtype=float, ndim=1)

spectrum wavelength definition domain

sflux: ndarray(dtype=float, ndim=1)

associated flux

flux: float

Energy of the spectrum within the filter

get_Nphotons(slamb, sflux, axis=-1)[source]

getNphot the number of photons through the filter (Ntot / width in the documentation)

getflux() * leff / hc

slamb: ndarray(dtype=float, ndim=1)

spectrum wavelength definition domain

sflux: ndarray(dtype=float, ndim=1)

associated flux in erg/s/cm2/AA

N: float

Number of photons of the spectrum within the filter

get_flux(slamb, sflux, axis=-1)[source]

getFlux Integrate the flux within the filter and return the integrated energy If you consider applying the filter to many spectra, you might want to consider extractSEDs.

slamb: ndarray(dtype=float, ndim=1)

spectrum wavelength definition domain

sflux: ndarray(dtype=float, ndim=1)

associated flux

flux: float

Energy of the spectrum within the filter

info(show_zeropoints=True)[source]

display information about the current filter

property leff

Unitwise Effective wavelength leff = int (lamb * T * Vega dlamb) / int(T * Vega dlamb)

property lmax

Calculated as the last value with a transmission at least 1% of maximum transmission

property lmin

Calculate das the first value with a transmission at least 1% of maximum transmission

property lphot

Photon distribution based effective wavelength. Defined as

lphot = int(lamb ** 2 * T * Vega dlamb) / int(lamb * T * Vega dlamb)

which we calculate as

lphot = get_flux(lamb * vega) / get_flux(vega)

property lpivot

Unitwise wavelength definition

classmethod make_integration_filter(lmin, lmax, name='', dtype='photon', unit=None)[source]

Generate an heavyside filter between lmin and lmax

reinterp(lamb)[source]

reinterpolate filter onto a different wavelength definition

set_dtype(dtype)[source]

Set the detector type (photon or energy)

set_wavelength_unit(unit)[source]

Set the wavelength units

to_Table(**kwargs)[source]

Export filter to a SimpleTable object

fname: str

filename

Uses SimpleTable parameters

to_dict()[source]

Return a dictionary of the filter

property wavelength

Unitwise wavelength definition

property width

Effective width Equivalent to the horizontal size of a rectangle with height equal to maximum transmission and with the same area that the one covered by the filter transmission curve.

W = int(T dlamb) / max(T)

write_to(fname, **kwargs)[source]

Export filter to a file

fname: str

filename

Uses SimpleTable.write parameters

class pyphot.sandbox.UnitHDF_Library(source='/github/workspace/pyphot/libs/new_filters.hd5', mode='r')[source]

Bases: pyphot.sandbox.UnitLibrary

Storage based on HDF

add_filter(f, **kwargs)[source]

Add a filter to the library permanently

f: Filter object

filter to add

get_library_content()[source]

get the content of the library

load_all_filters(interp=True, lamb=None)[source]

load all filters from the library

interp: bool

reinterpolate the filters over given lambda points

lamb: ndarray[float, ndim=1]

desired wavelength definition of the filter

filters: list[filter]

list of filter objects

load_filters(names, interp=True, lamb=None, filterLib=None)[source]

load a limited set of filters

names: list[str]

normalized names according to filtersLib

interp: bool

reinterpolate the filters over given lambda points

lamb: ndarray[float, ndim=1]

desired wavelength definition of the filter

filterLib: path

path to the filter library hd5 file

filters: list[filter]

list of filter objects

class pyphot.sandbox.UnitLibrary(source='/github/workspace/pyphot/libs/new_filters.hd5', *args, **kwargs)[source]

Bases: object

Common grounds for filter libraries

add_filter(f)[source]

add a filter to the library

property content

Get the content list

find(name, case_sensitive=True)[source]
classmethod from_ascii(filename, **kwargs)[source]
classmethod from_hd5(filename, **kwargs)[source]
get_library_content()[source]

get the content of the library

load_all_filters(interp=True, lamb=None)[source]

load all filters from the library

to_csv(directory='./', progress=True, **kwargs)[source]

Export each filter into a csv file with its own name Parameters ———- directory: str

directory to write into

progress: bool

show progress if set

to_hdf(fname='filters.hd5', progress=True, **kwargs)[source]

Export each filter into a csv file with its own name Parameters ———- directory: str

directory to write into

progress: bool

show progress if set

class pyphot.sandbox.UnitLickIndex(name, lick, unit='AA')[source]

Bases: pyphot.licks.LickIndex

Define a Lick Index similarily to a Filter object

get(wave, flux, **kwargs)[source]

compute spectral index after continuum subtraction

w: ndarray (nw, )

array of wavelengths in AA

flux: ndarray (N, nw)

array of flux values for different spectra in the series

degree: int (default 1)

degree of the polynomial fit to the continuum

nocheck: bool

set to silently pass on spectral domain mismatch. otherwise raises an error when index is not covered

ew: ndarray (N,)

equivalent width or magnitude array

ValueError: when the spectral coverage wave does not cover the index range

class pyphot.sandbox.UnitLickLibrary(fname='/github/workspace/pyphot/libs/licks.dat', comment='#')[source]

Bases: pyphot.licks.LickLibrary

Collection of Lick indices

property content
property description

any comment in the input file

find(name, case_sensitive=True)[source]
get_library_content()[source]
pyphot.sandbox.get_library(fname='/github/workspace/pyphot/libs/new_filters.hd5', **kwargs)[source]

Finds the appropriate class to load the library

pyphot.sandbox.hasUnit(val)[source]

Check is an object has units

pyphot.sandbox.reduce_resolution(wi, fi, fwhm0=<Quantity(0.55, 'angstrom')>, sigma_floor=<Quantity(0.2, 'angstrom')>)[source]

Adapt the resolution of the spectra to match the lick definitions

Lick definitions have different resolution elements as function of wavelength. These definition are hard-coded in this function

wi: ndarray (n, )

wavelength definition

fi: ndarray (nspec, n) or (n, )

spectra to convert

fwhm0: float

initial broadening in the spectra fi

sigma_floor: float

minimal dispersion to consider

flux_red: ndarray (nspec, n) or (n, )

reduced spectra

class pyphot.sandbox.set_method_default_units(wavelength_unit, flux_unit, output_unit=None)[source]

Bases: object

Decorator for classmethods that makes sure that the inputs of slamb, sflux are in given units

expects the decorated method to be defined as

>> def methodname(self, lamb, flux)

classmethod force_units(value, unit)[source]

pyphot.simpletable module

This file implements a Table class

that is designed to be the basis of any format

Requirements

  • FIT format:
    • astropy:

      provides a replacement to pyfits pyfits can still be used instead but astropy is now the default

  • HDF5 format:

    • pytables

RuntimeError will be raised when writing to a format associated with missing package.

class pyphot.simpletable.AstroHelpers[source]

Bases: object

Helpers related to astronomy data

static conesearch(ra0, dec0, ra, dec, r, outtype=0)[source]

Perform a cone search on a table

ra0: ndarray[ndim=1, dtype=float]

column name to use as RA source in degrees

dec0: ndarray[ndim=1, dtype=float]

column name to use as DEC source in degrees

ra: float

ra to look for (in degree)

dec: float

ra to look for (in degree)

r: float

distance in degrees

outtype: int
type of outputs

0 – minimal, indices of matching coordinates 1 – indices and distances of matching coordinates 2 – full, boolean filter and distances

t: tuple
if outtype is 0:

only return indices from ra0, dec0

elif outtype is 1:

return indices from ra0, dec0 and distances

elif outtype is 2:

return conditional vector and distance to all ra0, dec0

static deg2dms(val, delim=':')[source]

Convert degrees into hex coordinates

deg: float

angle in degrees

delimiter: str

character delimiting the fields

str: string or sequence

string to convert

static deg2hms(val, delim=':')[source]

Convert degrees into hex coordinates

deg: float

angle in degrees

delimiter: str

character delimiting the fields

str: string or sequence

string to convert

static dms2deg(_str, delim=':')[source]

Convert hex coordinates into degrees

str: string or sequence

string to convert

delimiter: str

character delimiting the fields

deg: float

angle in degrees

static euler(ai_in, bi_in, select, b1950=False, dtype='f8')[source]

Transform between Galactic, celestial, and ecliptic coordinates. Celestial coordinates (RA, Dec) should be given in equinox J2000 unless the b1950 is True.

select

From

To

select

From

To

1

RA-Dec (2000)

Galactic

4

Ecliptic

RA-Dec

2

Galactic

RA-DEC

5

Ecliptic

Galactic

3

RA-Dec

Ecliptic

6

Galactic

Ecliptic
long_in: float, or sequence

Input Longitude in DEGREES, scalar or vector.

lat_in: float, or sequence

Latitude in DEGREES

select: int

Integer from 1 to 6 specifying type of coordinate transformation.

b1950: bool

set equinox set to 1950

long_out: float, seq

Output Longitude in DEGREES

lat_out: float, seq

Output Latitude in DEGREES

Note

Written W. Landsman, February 1987 Adapted from Fortran by Daryl Yentis NRL Converted to IDL V5.0 W. Landsman September 1997 Made J2000 the default, added /FK4 keyword W. Landsman December 1998 Add option to specify SELECT as a keyword W. Landsman March 2003 Converted from IDL to numerical Python: Erin Sheldon, NYU, 2008-07-02

static hms2deg(_str, delim=':')[source]

Convert hex coordinates into degrees

str: string or sequence

string to convert

delimiter: str

character delimiting the fields

deg: float

angle in degrees

static sphdist(ra1, dec1, ra2, dec2)[source]

measures the spherical distance between 2 points

ra1: float or sequence

first right ascensions in degrees

dec1: float or sequence

first declination in degrees

ra2: float or sequence

second right ascensions in degrees

dec2: float or sequence

first declination in degrees

Outputs: float or sequence

returns a distance in degrees

class pyphot.simpletable.AstroTable(*args, **kwargs)[source]

Bases: pyphot.simpletable.SimpleTable

Derived from the Table, this class add implementations of common astro tools especially conesearch

coneSearch(ra, dec, r, outtype=0)[source]

Perform a cone search on a table

ra0: ndarray[ndim=1, dtype=float]

column name to use as RA source in degrees

dec0: ndarray[ndim=1, dtype=float]

column name to use as DEC source in degrees

ra: float

ra to look for (in degree)

dec: float

ra to look for (in degree)

r: float

distance in degrees

outtype: int
type of outputs

0 – minimal, indices of matching coordinates 1 – indices and distances of matching coordinates 2 – full, boolean filter and distances

t: tuple
if outtype is 0:

only return indices from ra0, dec0

elif outtype is 1:

return indices from ra0, dec0 and distances

elif outtype is 2:

return conditional vector and distance to all ra0, dec0

get_DEC(degree=True)[source]

Returns RA, converted from hexa/sexa into degrees

get_RA(degree=True)[source]

Returns RA, converted from hexa/sexa into degrees

info()[source]

prints information on the table

selectWhere(fields, condition=None, condvars=None, cone=None, zone=None, **kwargs)[source]

Read table data fulfilling the given condition. Only the rows fulfilling the condition are included in the result. conesearch is also possible through the keyword cone formatted as (ra, dec, r) zonesearch is also possible through the keyword zone formatted as (ramin, ramax, decmin, decmax)

Combination of multiple selections is also available.

set_DEC(val)[source]

Set the column that defines DEC coordinates

set_RA(val)[source]

Set the column that defines RA coordinates

where(condition=None, condvars=None, cone=None, zone=None, **kwargs)[source]

Read table data fulfilling the given condition. Only the rows fulfilling the condition are included in the result.

condition: str

expression to evaluate on the table includes mathematical operations and attribute names

condvars: dictionary, optional

A dictionary that replaces the local operands in current frame.

out: ndarray/ tuple of ndarrays result equivalent to np.where()

zoneSearch(ramin, ramax, decmin, decmax, outtype=0)[source]

Perform a zone search on a table, i.e., a rectangular selection

ramin: float

minimal value of RA

ramax: float

maximal value of RA

decmin: float

minimal value of DEC

decmax: float

maximal value of DEC

outtype: int
type of outputs

0 or 1 – minimal, indices of matching coordinates 2 – full, boolean filter and distances

r: sequence

indices or conditional sequence of matching values

class pyphot.simpletable.SimpleTable(fname, *args, **kwargs)[source]

Bases: object

Table class that is designed to be the basis of any format wrapping around numpy recarrays

fname: str or object

if str, the file to read from. This may be limited to the format currently handled automatically. If the format is not correctly handled, you can try by providing an object.__

if object with a structure like dict, ndarray, or recarray-like

the data will be encapsulated into a Table

caseless: bool

if set, column names will be caseless during operations

aliases: dict

set of column aliases (can be defined later set_alias())

units: dict

set of column units (can be defined later set_unit())

desc: dict

set of column description or comments (can be defined later set_comment())

header: dict

key, value pair corresponding to the attributes of the table

property Plotter

Plotter instance related to this dataset. Requires plotter add-on to work

addCol(name, data, dtype=None, unit=None, description=None)

Add one or multiple columns to the table

name: str or sequence(str)

The name(s) of the column(s) to add

data: ndarray, or sequence of ndarray

The column data, or sequence of columns

dtype: dtype

numpy dtype for the data to add

unit: str

The unit of the values in the column

description: str

A description of the content of the column

addLine(iterable)

Append one row in this table.

see also: stack()

iterable: iterable

line to add

add_column(name, data, dtype=None, unit=None, description=None)[source]

Add one or multiple columns to the table

name: str or sequence(str)

The name(s) of the column(s) to add

data: ndarray, or sequence of ndarray

The column data, or sequence of columns

dtype: dtype

numpy dtype for the data to add

unit: str

The unit of the values in the column

description: str

A description of the content of the column

append_row(iterable)[source]

Append one row in this table.

see also: stack()

iterable: iterable

line to add

property colnames

Sequence of column names

compress(condition, axis=None, out=None)[source]

Return selected slices of an array along given axis.

When working along a given axis, a slice along that axis is returned in output for each index where condition evaluates to True. When working on a 1-D array, compress is equivalent to extract.

condition1-D array of bools

Array that selects which entries to return. If len(condition) is less than the size of a along the given axis, then output is truncated to the length of the condition array.

axisint, optional

Axis along which to take slices. If None (default), work on the flattened array.

outndarray, optional

Output array. Its type is preserved and it must be of the right shape to hold the output.

compressed_arrayndarray

A copy of a without the slices along axis for which condition is false.

delCol(names)

Remove several columns from the table

names: sequence

A list containing the names of the columns to remove

property dtype

dtype of the data

property empty_row

Return an empty row array respecting the table format

evalexpr(expr, exprvars=None, dtype=<class 'float'>)[source]
evaluate expression based on the data and external variables

all np function can be used (log, exp, pi…)

expr: str

expression to evaluate on the table includes mathematical operations and attribute names

exprvars: dictionary, optional

A dictionary that replaces the local operands in current frame.

dtype: dtype definition

dtype of the output array

outNumPy array

array of the result

find_duplicate(index_only=False, values_only=False)[source]

Find duplication in the table entries, return a list of duplicated elements Only works at this time is 2 lines are the same entry not if 2 lines have the same values

get(v, full_match=False)[source]

returns a table from columns given as v

this function is equivalent to __getitem__() but preserve the Table format and associated properties (units, description, header)

v: str

pattern to filter the keys with

full_match: bool

if set, use re.fullmatch() instead of re.match()

groupby(*key)[source]

Create an iterator which returns (key, sub-table) grouped by each value of key(value)

key: str

expression or pattern to filter the keys with

key: str or sequence

group key

tab: SimpleTable instance

sub-table of the group header, aliases and column metadata are preserved (linked to the master table).

info()[source]

prints information on the table

items()[source]

Iterator on the (key, value) pairs

iterkeys()[source]

Iterator over the columns of the table

itervalues()[source]

Iterator over the lines of the table

join_by(r2, key, jointype='inner', r1postfix='1', r2postfix='2', defaults=None, asrecarray=False, asTable=True)[source]

Join arrays r1 and r2 on key key.

The key should be either a string or a sequence of string corresponding to the fields used to join the array. An exception is raised if the key field cannot be found in the two input arrays. Neither r1 nor r2 should have any duplicates along key: the presence of duplicates will make the output quite unreliable. Note that duplicates are not looked for by the algorithm.

key: str or seq(str)

corresponding to the fields used for comparison.

r2: Table

Table to join with

jointype: str in {‘inner’, ‘outer’, ‘leftouter’}

  • ‘inner’ : returns the elements common to both r1 and r2.

  • ‘outer’ : returns the common elements as well as the elements of r1 not in r2 and the elements of not in r2.

  • ‘leftouter’ : returns the common elements and the elements of r1 not in r2.

r1postfix: str

String appended to the names of the fields of r1 that are present in r2

r2postfix: str

String appended to the names of the fields of r2 that are present in r1

defaults: dict

Dictionary mapping field names to the corresponding default values.

tab: Table

joined table

Note

  • The output is sorted along the key.

  • A temporary array is formed by dropping the fields not in the key for the two arrays and concatenating the result. This array is then sorted, and the common entries selected. The output is constructed by filling the fields with the selected entries. Matching is not preserved if there are some duplicates…

keys(regexp=None, full_match=False)[source]

Return the data column names or a subset of it

regexp: str

pattern to filter the keys with

full_match: bool

if set, use re.fullmatch() instead of re.match()

Try to apply the pattern at the start of the string, returning a match object, or None if no match was found.

seq: sequence

sequence of keys

match(r2, key)[source]

Returns the indices at which the tables match matching uses 2 columns that are compared in values

r2: Table

second table to use

key: str

fields used for comparison.

indexes: tuple

tuple of both indices list where the two columns match.

property name

name of the table given by the Header[‘NAME’] attribute

property nbytes

number of bytes of the object

property ncols

number of columns

property nrows

number of lines

pop_columns(names)[source]

Pop several columns from the table

names: sequence

A list containing the names of the columns to remove

values: tuple

list of columns

pprint(idx=None, fields=None, ret=False, all=False, full_match=False, headerChar='-', delim=' | ', endline='\n', **kwargs)[source]
Pretty print the table content

you can select the table parts to display using idx to select the rows and fields to only display some columns (ret is only for insternal use)

idx: sequence, slide

sub selection to print

fields: str, sequence

if str can be a regular expression, and/or list of fields separated by spaces or commas

ret: bool

if set return the string representation instead of printing the result

all: bool

if set, force to show all rows

headerChar: char

Character to be used for the row separator line

delim: char

The column delimiter.

pprint_entry(num, keys=None)[source]

print one line with key and values properly to be readable

num: int, slice

indice selection

keys: sequence or str

if str, can be a regular expression if sequence, the sequence of keys to print

remove_column(names)

Remove several columns from the table

names: sequence

A list containing the names of the columns to remove

remove_columns(names)[source]

Remove several columns from the table

names: sequence

A list containing the names of the columns to remove

resolve_alias(colname)[source]

Return the name of an aliased column.

Given an alias, return the column name it aliases. This function is a no-op if the alias is a column name itself.

Aliases are defined by using .define_alias()

reverse_alias(colname)[source]

Return aliases of a given column.

Given a colname, return a sequence of aliases associated to this column Aliases are defined by using .define_alias()

select(fields, indices=None, **kwargs)[source]

Select only a few fields in the table

fields: str or sequence

fields to keep in the resulting table

indices: sequence or slice

extract only on these indices

tab: SimpleTable instance

resulting table

selectWhere(fields, condition, condvars=None, **kwargs)[source]
Read table data fulfilling the given condition.

Only the rows fulfilling the condition are included in the result.

fields: str or sequence

fields to keep in the resulting table

condition: str

expression to evaluate on the table includes mathematical operations and attribute names

condvars: dictionary, optional

A dictionary that replaces the local operands in current frame.

tab: SimpleTable instance

resulting table

setComment(colname, comment)

Set the comment of a column referenced by its name

colname: str

column name or registered alias

comment: str

column description

setUnit(colname, unit)

Set the unit of a column referenced by its name

colname: str

column name or registered alias

unit: str

unit description

set_alias(alias, colname)[source]

Define an alias to a column

alias: str

The new alias of the column

colname: str

The column being aliased

set_comment(colname, comment)[source]

Set the comment of a column referenced by its name

colname: str

column name or registered alias

comment: str

column description

set_unit(colname, unit)[source]

Set the unit of a column referenced by its name

colname: str

column name or registered alias

unit: str

unit description

property shape

shape of the data

sort(keys, copy=False)[source]

Sort the table inplace according to one or more keys. This operates on the existing table (and does not return a new table).

keys: str or seq(str)

The key(s) to order by

copy: bool

if set returns a sorted copy instead of working inplace

stack(r, *args, **kwargs)[source]

Superposes arrays fields by fields inplace

t.stack(t1, t2, t3, default=None, inplace=True)

r: Table

stats(fn=None, fields=None, fill=None)[source]

Make statistics on columns of a table

fn: callable or sequence of callables

functions to apply to each column default: (np.mean, np.std, np.nanmin, np.nanmax)

fields: str or sequence

any key or key expression to subselect columns default is all columns

fill: value

value when not applicable default np.nan

tab: Table instance

collection of statistics, one column per function in fn and 1 ligne per column in the table

take(indices, axis=None, out=None, mode='raise')[source]

Take elements from an array along an axis.

This function does the same thing as “fancy” indexing (indexing arrays using arrays); however, it can be easier to use if you need elements along a given axis.

indicesarray_like

The indices of the values to extract. Also allow scalars for indices.

axisint, optional

The axis over which to select values. By default, the flattened input array is used.

outndarray, optional

If provided, the result will be placed in this array. It should be of the appropriate shape and dtype.

mode{‘raise’, ‘wrap’, ‘clip’}, optional

Specifies how out-of-bounds indices will behave.

  • ‘raise’ – raise an error (default)

  • ‘wrap’ – wrap around

  • ‘clip’ – clip to the range

‘clip’ mode means that all indices that are too large are replaced by the index that addresses the last element along that axis. Note that this disables indexing with negative numbers.

subarrayndarray

The returned array has the same type as a.

to_astropy_table(**kwargs)[source]

A class to represent tables of heterogeneous data.

astropy.table.Table provides a class for heterogeneous tabular data, making use of a numpy structured array internally to store the data values. A key enhancement provided by the Table class is the ability to easily modify the structure of the table by adding or removing columns, or adding new rows of data. In addition table and column metadata are fully supported.

maskedbool, optional

Specify whether the table is masked.

nameslist, optional

Specify column names

dtypelist, optional

Specify column data types

metadict, optional

Metadata associated with the table.

copybool, optional

Copy the input data (default=True).

rowsnumpy ndarray, list of lists, optional

Row-oriented data for table instead of data argument

copy_indicesbool, optional

Copy any indices in the input data (default=True)

**kwargsdict, optional

Additional keyword args when converting table-like object

df: astropy.table.Table

dataframe

to_dask(**kwargs)[source]

Construct a Dask DataFrame

This splits an in-memory Pandas dataframe into several parts and constructs a dask.dataframe from those parts on which Dask.dataframe can operate in parallel.

Note that, despite parallelism, Dask.dataframe may not always be faster than Pandas. We recommend that you stay with Pandas for as long as possible before switching to Dask.dataframe.

keys: sequence, optional

ordered subset of columns to export

npartitionsint, optional

The number of partitions of the index to create. Note that depending on the size and index of the dataframe, the output may have fewer partitions than requested.

chunksizeint, optional

The size of the partitions of the index.

sort: bool

Sort input first to obtain cleanly divided partitions or don’t sort and don’t get cleanly divided partitions

name: string, optional

An optional keyname for the dataframe. Defaults to hashing the input

dask.DataFrame or dask.Series

A dask DataFrame/Series partitioned along the index

to_dict(keys=None, contiguous=False)[source]

Construct a dictionary from this dataframe with contiguous arrays

keys: sequence, optional

ordered subset of columns to export

contiguous: boolean

make sure each value is a contiguous numpy array object (C-aligned)

data: dict

converted data

to_pandas(**kwargs)[source]

Construct a pandas dataframe

datandarray

(structured dtype), list of tuples, dict, or DataFrame

keys: sequence, optional

ordered subset of columns to export

indexstring, list of fields, array-like

Field of array to use as the index, alternately a specific set of input labels to use

excludesequence, default None

Columns or fields to exclude

columnssequence, default None

Column names to use. If the passed data do not have names associated with them, this argument provides names for the columns. Otherwise this argument indicates the order of the columns in the result (any names not found in the data will become all-NA columns)

coerce_floatboolean, default False

Attempt to convert values to non-string, non-numeric objects (like decimal.Decimal) to floating point, useful for SQL result sets

df : DataFrame

to_records(**kwargs)[source]

Construct a numpy record array from this dataframe

to_vaex(**kwargs)[source]

Create an in memory Vaex dataset

name: str

unique for the dataset

keys: sequence, optional

ordered subset of columns to export

df: vaex.DataSetArrays

vaex dataset

to_xarray(**kwargs)[source]

Construct an xarray dataset

Each column will be converted into an independent variable in the Dataset. If the dataframe’s index is a MultiIndex, it will be expanded into a tensor product of one-dimensional indices (filling in missing values with NaN). This method will produce a Dataset very similar to that on which the ‘to_dataframe’ method was called, except with possibly redundant dimensions (since all dataset variables will have the same dimensionality).

where(condition, condvars=None, *args, **kwargs)[source]

Read table data fulfilling the given condition. Only the rows fulfilling the condition are included in the result.

condition: str

expression to evaluate on the table includes mathematical operations and attribute names

condvars: dictionary, optional

A dictionary that replaces the local operands in current frame.

out: ndarray/ tuple of ndarrays result equivalent to np.where()

write(fname, **kwargs)[source]

write table into file

fname: str

filename to export the table into

Note

additional keywords are forwarded to the corresponding libraries pyfits.writeto() or pyfits.append() np.savetxt()

class pyphot.simpletable.stats[source]

Bases: object

classmethod has_nan(v)[source]
classmethod max(v)[source]
classmethod mean(v)[source]
classmethod min(v)[source]
classmethod p16(v)[source]
classmethod p50(v)[source]
classmethod p84(v)[source]
classmethod std(v)[source]
classmethod var(v)[source]

pyphot.sun module

Handle the Sun Spectrum

class pyphot.sun.Sun(source=None, distance=<Quantity(1, 'astronomical_unit')>, flavor='theoretical')[source]

Bases: object

Class that handles the Sun’s spectrum and references.

Observed solar spectrum comes from: ftp://ftp.stsci.edu/cdbs/current_calspec/sun_reference_stis_001.fits

and theoretical spectrum comes from: ftp://ftp.stsci.edu/cdbs/grid/k93models/standards/sun_kurucz93.fits

The theoretical spectrum is scaled to match the observed spectrum from 1.5 - 2.5 microns, and then it is used where the observed spectrum ends. The theoretical model of the Sun from Kurucz’93 atlas using the following parameters when the Sun is at 1 au.

log_Z T_eff log_g V_{Johnson} +0.0 5777 +4.44 -26.75

source: str

filename of the sun library

data: SimpleTable

data table

units: tuple

detected units from file header

wavelength: array

wavelength (with units when found)

flux: array

flux(wavelength) values (with units when provided)

distance: float

distance to the observed Sun (default, 1 au)

flavor: str, (default theoretical)

either ‘observed’ using the stis reference, or ‘theoretical’ for the Kurucz model.

property flux

flux(wavelength) values (with units when provided)

property wavelength

wavelength (with units when found)

pyphot.svo module

Link to the SVO filter profile service

http://svo2.cab.inta-csic.es/theory/fps/

If your research benefits from the use of the SVO Filter Profile Service, include the following acknowledgement in your publication:

> This research has made use of the SVO Filter Profile Service > (http://svo2.cab.inta-csic.es/theory/fps/) supported from the Spanish MINECO > through grant AYA2017-84089.

and please include the following references in your publication:

Example

>>> lst = "2MASS/2MASS.J 2MASS/2MASS.H 2MASS/2MASS.Ks HST/ACS_WFC.F475W HST/ACS_WFC.F814W".split()
    objects = [get_pyphot_filter(k) for k in lst]
pyphot.svo.get_pyphot_astropy_filter(identifier: str)[source]

Query the SVO filter profile service and return the filter object

identifierstr

SVO identifier of the filter profile e.g., 2MASS/2MASS.Ks HST/ACS_WFC.F475W The identifier is the first column on the webpage of the facilities.

filterpyphot.astropy.UnitFilter

Filter object

pyphot.svo.get_pyphot_filter(identifier: str)[source]

Query the SVO filter profile service and return the filter object

identifierstr

SVO identifier of the filter profile e.g., 2MASS/2MASS.Ks HST/ACS_WFC.F475W The identifier is the first column on the webpage of the facilities.

filterpyphot.astropy.UnitFilter

Filter object

pyphot.vega module

Handle vega spec/mags/fluxes manipulations

Works with both ascii and hd5 files for back-compatibility

Vega.wavelength and Vega.flux have now units!

class pyphot.vega.Vega(source='/github/workspace/pyphot/libs/vega.hd5')[source]

Bases: object

Class that handles vega spectrum and references. This class know where to find the Vega synthetic spectrum (Bohlin 2007) in order to compute fluxes and magnitudes in given filters

source: str

filename of the vega library

data: SimpleTable

data table

units: tuple

detected units from file header

wavelength: array

wavelength (with units when found)

flux: array

flux(wavelength) values (with units when provided)

An instance can be used as a context manager as:

>>> filters = ['HST_WFC3_F275W', 'HST_WFC3_F336W', 'HST_WFC3_F475W',                   'HST_WFC3_F814W', 'HST_WFC3_F110W', 'HST_WFC3_F160W']
    with Vega() as v:
        vega_f, vega_mag, flamb = v.getSed(filters)
    print vega_f, vega_mag, flamb
property flux

flux(wavelength) values (with units when provided)

getFlux(filters)[source]

Return vega abs. fluxes in filters

getMag(filters)[source]

Return vega abs. magnitudes in filters

property wavelength

wavelength (with units when found)

pyphot.vega.from_Vegamag_to_Flux(lamb, vega_mag)[source]

function decorator that transforms vega magnitudes to fluxes (without vega reference)

pyphot.vega.from_Vegamag_to_Flux_SN_errors(lamb, vega_mag)[source]

function decorator that transforms vega magnitudes to fluxes (without vega reference)

Module contents