DistortionLookupTable¶
-
class
astropy.wcs.
DistortionLookupTable
(*table*, *crpix*, *crval*, *cdelt*)¶ Bases:
object
Represents a single lookup table for a distortion paper transformation.
Parameters: - table : 2-dimensional array
The distortion lookup table.
- crpix : 2-tuple
The distortion array reference pixel
- crval : 2-tuple
The image array pixel coordinate
- cdelt : 2-tuple
The grid step size
Attributes Summary
cdelt
double array[naxis]
Coordinate increments (CDELTia
) for each coord axis.crpix
double array[naxis]
Coordinate reference pixels (CRPIXja
) for each pixel axis.crval
double array[naxis]
Coordinate reference values (CRVALia
) for each coordinate axis.data
float array
The array data for theDistortionLookupTable
.Methods Summary
get_offset
(x, y)Returns the offset as defined in the distortion lookup table. Attributes Documentation
-
cdelt
¶ double array[naxis]
Coordinate increments (CDELTia
) for each coord axis.If a
CDi_ja
linear transformation matrix is present, a warning is raised andcdelt
is ignored. TheCDi_ja
matrix may be deleted by:del wcs.wcs.cd
An undefined value is represented by NaN.
-
crpix
¶ double array[naxis]
Coordinate reference pixels (CRPIXja
) for each pixel axis.
-
crval
¶ double array[naxis]
Coordinate reference values (CRVALia
) for each coordinate axis.
-
data
¶ float array
The array data for theDistortionLookupTable
.
Methods Documentation
-
get_offset
(x, y) -> (x, y)¶ Returns the offset as defined in the distortion lookup table.
Returns: - coordinate : coordinate pair
The offset from the distortion table for pixel point (x, y).