PixTable

class mpdaf.drs.PixTable(filename, xpos=None, ypos=None, lbda=None, data=None, dq=None, stat=None, origin=None, weight=None, primary_header=None, save_as_ima=True, wcs=Unit('pix'), wave=Unit('Angstrom'), unit_data=Unit('ct'))[source]

Bases: object

PixTable class.

This class manages input/output for MUSE pixel table files. The FITS file is opened with memory mapping. Just the primary header and table dimensions are loaded. The methods get_xpos, get_ypos, get_lambda, get_data, get_dq, get_stat and get_origin must be used to get columns data.

Parameters:

filenamestr: The FITS file name. None by default.

Attributes:

filenamestr: The FITS file name. None if any.
primary_headerastropy.io.fits.Header: The primary header.
nrowsint: Number of rows.
nifuint: Number of merged IFUs that went into this pixel table.
wcsastropy.units.Unit: Type of spatial coordinates of this pixel table (u.pix, u.deg or u.rad)
waveastropy.units.Unit: Type of spectral coordinates of this pixel table
imabool: If True, pixtable is saved as multi-extension FITS image instead of FITS binary table.

Attributes Summary

`fluxcal`	If True, this pixel table was flux-calibrated.
`projection`	Return the projection type.
`skysub`	If True, this pixel table was sky-subtracted.

Methods Summary

`copy`()	Copy PixTable object in a new one and returns it.
`extract`([filename, sky, lbda, ifu, sl, ...])	Extracts a subset of a pixtable using the following criteria:
`extract_from_mask`(mask)	Return a new pixtable extracted with the given mask.
`get_column`(name[, ksel])	Load a column and return it.
`get_data`([ksel, unit])	Load the data column and return it.
`get_dq`([ksel])	Load the dq column and return it.
`get_exp`()	Load the exposure numbers and return it as a column.
`get_keyword`(key[, default])	Return the keyword value corresponding to key, adding the keyword prefix (`'HIERARCH ESO DRS MUSE PIXTABLE'`).
`get_lambda`([ksel, unit])	Load the lambda column and return it.
`get_origin`([ksel])	Load the origin column and return it.
`get_pos_sky`([xpos, ypos])	Return the absolute position on the sky in degrees/pixel.
`get_row`(idx)	Return a row of the pixtable, or rows if given a list of indices.
`get_stat`([ksel, unit])	Load the stat column and return it.
`get_weight`([ksel])	Load the weight column and return it.
`get_xpos`([ksel, unit])	Load the xpos column and return it.
`get_ypos`([ksel, unit])	Load the ypos column and return it.
`info`()	Print information.
`mask_column`([maskfile])	Compute the mask column corresponding to a mask file.
`origin2coords`(origin)	Converts the origin value and returns (ifu, slice, ypix, xpix).
`origin2ifu`(origin)	Converts the origin value and returns the ifu number.
`origin2slice`(origin)	Converts the origin value and returns the slice number.
`origin2xoffset`(origin[, ifu, sli])	Converts the origin value and returns the x coordinates offset.
`origin2xpix`(origin[, ifu, sli])	Converts the origin value and returns the x coordinates.
`origin2ypix`(origin)	Converts the origin value and returns the y coordinates.
`reconstruct_det_image`([xstart, ystart, ...])	Reconstructs the image on the detector from the pixtable.
`reconstruct_det_waveimage`()	Reconstructs an image of wavelength values on the detector from the pixtable.
`select_exp`(exp, col_exp)	Return a mask corresponding to given exposure numbers.
`select_ifus`(ifus[, origin])	Return a mask corresponding to given ifus.
`select_lambda`(lbda[, unit])	Return a mask corresponding to the given wavelength range.
`select_sky`(sky)	Return a mask corresponding to the given aperture on the sky (center, size and shape)
`select_slices`(slices[, origin])	Return a mask corresponding to given slices.
`select_stacks`(stacks[, origin])	Return a mask corresponding to given stacks.
`select_xpix`(xpix[, origin])	Return a mask corresponding to given detector pixels.
`select_ypix`(ypix[, origin])	Return a mask corresponding to given detector pixels.
`set_column`(name, data[, ksel])	Set a column (or a part of it).
`set_data`(data[, ksel, unit])	Set data column (or a part of it).
`set_dq`(dq[, ksel])	Set dq column (or a part of it).
`set_keyword`(key, val)	Set the keyword value corresponding to key, adding the keyword prefix (`'HIERARCH ESO DRS MUSE PIXTABLE'`).
`set_lambda`(lbda[, ksel, unit])	Set lambda column (or a part of it).
`set_origin`(origin[, ksel])	Set origin column (or a part of it).
`set_stat`(stat[, ksel, unit])	Set stat column (or a part of it).
`set_weight`(weight[, ksel])	Set weight column (or a part of it).
`set_xpos`(xpos[, ksel, unit])	Set xpos column (or a part of it).
`set_ypos`(ypos[, ksel, unit])	Set ypos column (or a part of it).
`write`(filename[, save_as_ima])	Save the object in a FITS file.

Attributes Documentation

fluxcal: If True, this pixel table was flux-calibrated.

projection

Return the projection type.

‘positioned’ for positioned pixtables
‘projected’ for reduced pixtables

skysub: If True, this pixel table was sky-subtracted.

Methods Documentation

copy()[source]: Copy PixTable object in a new one and returns it.

extract(filename=None, sky=None, lbda=None, ifu=None, sl=None, xpix=None, ypix=None, exp=None, stack=None, method='and')[source]

Extracts a subset of a pixtable using the following criteria:

aperture on the sky (center, size and shape)
wavelength range
IFU numbers
slice numbers
detector pixels
exposure numbers
stack numbers

The arguments can be either single value or a list of values to select multiple regions.

Parameters:

filenamestr: The FITS filename used to save the resulted object.
sky(float, float, float, char): (y, x, size, shape) extract an aperture on the sky, defined by a center (y, x) in degrees/pixel, a shape (‘C’ for circular, ‘S’ for square) and size (radius or half side length) in arcsec/pixels.
lbda(float, float): (min, max) wavelength range in angstrom.
ifuint or list: IFU number.
slint or list: Slice number on the CCD.
xpix(int, int) or list: (min, max) pixel range along the X axis
ypix(int, int) or list: (min, max) pixel range along the Y axis
explist of int: List of exposure numbers
stacklist of int: List of stack numbers
method‘and’ or ‘or’: Logical operation used to merge the criteria

Returns:

outPixTable

extract_from_mask(mask)[source]

Return a new pixtable extracted with the given mask.

Parameters:

masknumpy.ndarray: Mask (array of bool).

Returns:

outPixTable

get_column(name, ksel=None)[source]

Load a column and return it.

Parameters:

namestr or attribute: Name of the column.
kseloutput of np.where: Elements depending on a condition.

Returns:

outnumpy.array

get_data(ksel=None, unit=None)[source]

Load the data column and return it.

Parameters:

kseloutput of np.where: Elements depending on a condition.
unitastropy.units.Unit: Unit of the returned data.

Returns:

outnumpy.array

get_dq(ksel=None)[source]

Load the dq column and return it.

Parameters:

kseloutput of np.where: Elements depending on a condition.

Returns:

outnumpy.array

get_exp()[source]

Load the exposure numbers and return it as a column.

Returns:

outnumpy.memmap

get_keyword(key, default=<object object>)[source]

Return the keyword value corresponding to key, adding the keyword prefix ('HIERARCH ESO DRS MUSE PIXTABLE').

Parameters:

keystr: Keyword.

Returns:

outkeyword value

get_lambda(ksel=None, unit=None)[source]

Load the lambda column and return it.

Parameters:

kseloutput of np.where: Elements depending on a condition.
unitastropy.units.Unit: Unit of the returned data.

Returns:

outnumpy.array

get_origin(ksel=None)[source]

Load the origin column and return it.

Parameters:

kseloutput of np.where: Elements depending on a condition.

Returns:

outnumpy.array

get_pos_sky(xpos=None, ypos=None)[source]

Return the absolute position on the sky in degrees/pixel.

Parameters:

xposnumpy.array: xpos values
yposnumpy.array: ypos values

Returns:

xpos_sky, ypos_skynumpy.array, numpy.array

get_row(idx)[source]

Return a row of the pixtable, or rows if given a list of indices.

Parameters:

idxint or list of int or ndarray: The row indices.

Returns:

dict: The method returns a dict with a value or array of values for each column of the pixtable.

get_stat(ksel=None, unit=None)[source]

Load the stat column and return it.

Parameters:

kseloutput of np.where: Elements depending on a condition.
unitastropy.units.Unit: Unit of the returned data.

Returns:

outnumpy.array

get_weight(ksel=None)[source]

Load the weight column and return it.

Parameters:

kseloutput of np.where: Elements depending on a condition.

Returns:

outnumpy.array

get_xpos(ksel=None, unit=None)[source]

Load the xpos column and return it.

Parameters:

kseloutput of np.where: Elements depending on a condition.
unitastropy.units.Unit: Unit of the returned data.

Returns:

outnumpy.array

get_ypos(ksel=None, unit=None)[source]

Load the ypos column and return it.

Parameters:

kseloutput of np.where: Elements depending on a condition.
unitastropy.units.Unit: Unit of the returned data.

Returns:

outnumpy.array

info()[source]: Print information.

mask_column(maskfile=None)[source]

Compute the mask column corresponding to a mask file.

Parameters:

maskfilestr: Path to a FITS image file with WCS information, used to mask out bright continuum objects present in the FoV. Values must be 0 for the background and >0 for objects.

Returns:

outmpdaf.drs.PixTableMask

origin2coords(origin)[source]

Converts the origin value and returns (ifu, slice, ypix, xpix).

Parameters:

originint: Origin value.

Returns:

out(int, int, float, float)

origin2ifu(origin)[source]

Converts the origin value and returns the ifu number.

Parameters:

originint: Origin value.

Returns:

outint

origin2slice(origin)[source]

Converts the origin value and returns the slice number.

Parameters:

originint: Origin value.

Returns:

outint

origin2xoffset(origin, ifu=None, sli=None)[source]

Converts the origin value and returns the x coordinates offset.

Parameters:

originint: Origin value.

Returns:

outfloat

origin2xpix(origin, ifu=None, sli=None)[source]

Converts the origin value and returns the x coordinates.

Parameters:

originint: Origin value.

Returns:

outfloat

origin2ypix(origin)[source]

Converts the origin value and returns the y coordinates.

Parameters:

originint: Origin value.

Returns:

outfloat

reconstruct_det_image(xstart=None, ystart=None, xstop=None, ystop=None)[source]

Reconstructs the image on the detector from the pixtable.

The pixtable must concerns only one IFU, otherwise an exception is raised.

Returns:

outImage

reconstruct_det_waveimage()[source]

Reconstructs an image of wavelength values on the detector from the pixtable. The pixtable must concerns only one IFU, otherwise an exception is raised.

Returns:

outImage

select_exp(exp, col_exp)[source]

Return a mask corresponding to given exposure numbers.

Parameters:

explist of int: List of exposure numbers

Returns:

outarray of bool: mask

select_ifus(ifus, origin=None)[source]

Return a mask corresponding to given ifus.

Parameters:

ifuint or list: IFU number.

Returns:

outarray of bool: mask

select_lambda(lbda, unit=Unit('Angstrom'))[source]

Return a mask corresponding to the given wavelength range.

Parameters:

lbda(float, float): (min, max) wavelength range in angstrom.
unitastropy.units.Unit: Unit of the wavelengths in input.

Returns:

outarray of bool: mask

select_sky(sky)[source]

Return a mask corresponding to the given aperture on the sky (center, size and shape)

Parameters:

sky(float, float, float, char): (y, x, size, shape) extract an aperture on the sky, defined by a center (y, x) in degrees/pixel, a shape (‘C’ for circular, ‘S’ for square) and size (radius or half side length) in arcsec/pixels.

Returns:

outarray of bool: mask

select_slices(slices, origin=None)[source]

Return a mask corresponding to given slices.

Parameters:

sliceslist of int: Slice number on the CCD.

Returns:

outarray of bool: mask

select_stacks(stacks, origin=None)[source]

Return a mask corresponding to given stacks.

Parameters:

stackslist of int: Stacks numbers (1,2,3 or 4)
Returns
——-
outarray of bool: mask

select_xpix(xpix, origin=None)[source]

Return a mask corresponding to given detector pixels.

Parameters:

xpixlist: [(min, max)] pixel range along the X axis

Returns:

outarray of bool: mask

select_ypix(ypix, origin=None)[source]

Return a mask corresponding to given detector pixels.

Parameters:

ypixlist: [(min, max)] pixel range along the Y axis

Returns:

outarray of bool: mask

set_column(name, data, ksel=None)[source]

Set a column (or a part of it).

Parameters:

namestr or attribute: Name of the column.
datanumpy.array: data values
kseloutput of np.where: Elements depending on a condition.

set_data(data, ksel=None, unit=None)[source]

Set data column (or a part of it).

Parameters:

datanumpy.array: data values
kseloutput of np.where: Elements depending on a condition.
unitastropy.units.Unit: unit of the data column in input.

set_dq(dq, ksel=None)[source]

Set dq column (or a part of it).

Parameters:

dqnumpy.array: dq values
kseloutput of np.where: Elements depending on a condition.

set_keyword(key, val)[source]

Set the keyword value corresponding to key, adding the keyword prefix ('HIERARCH ESO DRS MUSE PIXTABLE').

Parameters:

keystr: Keyword.
valstr or int or float: Value.

set_lambda(lbda, ksel=None, unit=None)[source]

Set lambda column (or a part of it).

Parameters:

lbdanumpy.array: lbda values
kseloutput of np.where: Elements depending on a condition.
unitastropy.units.Unit: unit of the lambda column in input.

set_origin(origin, ksel=None)[source]

Set origin column (or a part of it).

Parameters:

originnumpy.array: origin values
kseloutput of np.where: Elements depending on a condition.

set_stat(stat, ksel=None, unit=None)[source]

Set stat column (or a part of it).

Parameters:

statnumpy.array: stat values
kseloutput of np.where: Elements depending on a condition.
unitastropy.units.Unit: unit of the stat column in input.

set_weight(weight, ksel=None)[source]

Set weight column (or a part of it).

Parameters:

weightnumpy.array: weight values
kseloutput of np.where: Elements depending on a condition.

set_xpos(xpos, ksel=None, unit=None)[source]

Set xpos column (or a part of it).

Parameters:

xposnumpy.array: xpos values
kseloutput of np.where: Elements depending on a condition.
unitastropy.units.Unit: unit of the xpos column in input.

set_ypos(ypos, ksel=None, unit=None)[source]

Set ypos column (or a part of it).

Parameters:

yposnumpy.array: ypos values
kseloutput of np.where: Elements depending on a condition.
unitastropy.units.Unit: unit of the ypos column in input.

write(filename, save_as_ima=True)[source]

Save the object in a FITS file.

Parameters:

filenamestr: The FITS filename.
save_as_imabool: If True, pixtable is saved as multi-extension FITS image instead of FITS binary table.