WaveCoord¶
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class
mpdaf.obj.
WaveCoord
(hdr=None, crpix=1.0, cdelt=1.0, crval=1.0, cunit=Unit("Angstrom"), ctype='LINEAR', shape=None)[source]¶ Bases:
object
WaveCoord class manages world coordinates in spectral direction.
Parameters: - hdr : astropy.fits.CardList
A FITS header. If hdr is not None, WaveCoord object is created from this header and other parameters are not used.
- crpix : float
Reference pixel coordinates. 1.0 by default. Note that for crpix definition, the first pixel in the spectrum has pixel coordinates.
- cdelt : float
Step in wavelength (1.0 by default).
- crval : float
Coordinates of the reference pixel (0.0 by default).
- cunit : u.unit
Wavelength unit (Angstrom by default).
- ctype : string
Type of the coordinates.
- shape : integer or None
Size of spectrum (no mandatory).
Attributes: - shape : integer
Size of spectrum.
- wcs : astropy.wcs.WCS
Wavelength coordinates.
Methods Summary
coord
([pixel, unit])Return the coordinate corresponding to pixel. copy
()Copie WaveCoord object in a new one and returns it. get_crpix
()CRPIX getter (reference pixel on the wavelength axis). get_crval
([unit])CRVAL getter (value of the reference pixel on the wavelength axis). get_ctype
()Return the type of wavelength coordinates. get_end
([unit])Return the value of the last pixel. get_range
([unit])Return the wavelength range [Lambda_min,Lambda_max]. get_start
([unit])Return the value of the first pixel. get_step
([unit])Return the step in wavelength. info
([unit])Print information. isEqual
(other)Return True if other and self have the same attributes. pixel
(lbda[, nearest, unit])Return the decimal pixel corresponding to the wavelength lbda. rebin
(factor)Rebin to a new coordinate system (in place). resample
(step, start[, unit])Resample to a new coordinate system. set_crpix
(x)CRPIX setter (reference pixel on the wavelength axis). set_crval
(x[, unit])CRVAL getter (value of the reference pixel on the wavelength axis). set_step
(x[, unit])Return the step in wavelength. to_header
([naxis, use_cd])Generate a astropy.fits header object with the WCS information. Methods Documentation
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coord
(pixel=None, unit=None)[source]¶ Return the coordinate corresponding to pixel.
If pixel is None (default value), the full coordinate array is returned.
Parameters: - pixel : int, array or None.
pixel value.
- unit :
astropy.units.Unit
type of the wavelength coordinates
Returns: - out : float or array of float
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get_crval
(unit=None)[source]¶ CRVAL getter (value of the reference pixel on the wavelength axis).
Parameters: - unit :
astropy.units.Unit
type of the wavelength coordinates
- unit :
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get_end
(unit=None)[source]¶ Return the value of the last pixel.
Parameters: - unit :
astropy.units.Unit
type of the wavelength coordinates
- unit :
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get_range
(unit=None)[source]¶ Return the wavelength range [Lambda_min,Lambda_max].
Parameters: - unit :
astropy.units.Unit
type of the wavelength coordinates
- unit :
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get_start
(unit=None)[source]¶ Return the value of the first pixel.
Parameters: - unit :
astropy.units.Unit
type of the wavelength coordinates
- unit :
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get_step
(unit=None)[source]¶ Return the step in wavelength.
Parameters: - unit :
astropy.units.Unit
type of the wavelength coordinates
- unit :
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pixel
(lbda, nearest=False, unit=None)[source]¶ Return the decimal pixel corresponding to the wavelength lbda.
If nearest=True; returns the nearest integer pixel.
Parameters: - lbda : float or array
wavelength value.
- nearest : bool
If nearest is True returns the nearest integer pixel in place of the decimal pixel.
- unit :
astropy.units.Unit
type of the wavelength coordinates
Returns: - out : float or integer
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rebin
(factor)[source]¶ Rebin to a new coordinate system (in place).
Parameters: - factor : integer
Factor.
Returns: - out : WaveCoord
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resample
(step, start, unit=None)[source]¶ Resample to a new coordinate system.
Parameters: - start : float
New wavelength for the pixel 0.
- step : float
New step.
- unit :
astropy.units.Unit
type of the wavelength coordinates
Returns: - out : WaveCoord
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set_crval
(x, unit=None)[source]¶ CRVAL getter (value of the reference pixel on the wavelength axis).
Parameters: - x : float
value of the reference pixel on the wavelength axis
- unit :
astropy.units.Unit
type of the wavelength coordinates
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set_step
(x, unit=None)[source]¶ Return the step in wavelength.
Parameters: - x : float
Step value
- unit :
astropy.units.Unit
type of the wavelength coordinates