ComputePixelScale¶

class lsst.pipe.tasks.functors.ComputePixelScale(colCD_1_1, colCD_1_2, colCD_2_1, colCD_2_2, **kwargs)¶

Bases: lsst.pipe.tasks.functors.LocalWcs

Compute the local pixel scale from the stored CDMatrix.

Attributes Summary

`columns`	Columns required to perform calculation
`name`
`noDup`
`shortname`	Short name of functor (suitable for column name/dict key)

Methods Summary

`__call__`(data[, dropna])	Call self as a function.
`computeDeltaRaDec`(x, y, cd11, cd12, cd21, cd22)	Compute the distance on the sphere from x2, y1 to x1, y1.
`computeSkySeperation`(ra1, dec1, ra2, dec2)	Compute the local pixel scale conversion.
`difference`(data1, data2, **kwargs)	Computes difference between functor called on two different ParquetTable objects
`fail`(df)
`getSkySeperationFromPixel`(x1, y1, x2, y2, …)	Compute the distance on the sphere from x2, y1 to x1, y1.
`multilevelColumns`(data[, columnIndex, …])	Returns columns needed by functor from multilevel dataset
`pixelScaleArcseconds`(cd11, cd12, cd21, cd22)	Compute the local pixel to scale conversion in arcseconds.

Attributes Documentation

columns¶: Columns required to perform calculation

name = 'PixelScale'¶

noDup¶

shortname¶: Short name of functor (suitable for column name/dict key)

Methods Documentation

__call__(data, dropna=False)¶: Call self as a function.

computeDeltaRaDec(x, y, cd11, cd12, cd21, cd22)¶

Compute the distance on the sphere from x2, y1 to x1, y1.

Parameters:

x : pandas.Series: X pixel coordinate.
y : pandas.Series: Y pixel coordinate.
cd11 : pandas.Series: [1, 1] element of the local Wcs affine transform.
cd11 : pandas.Series: [1, 1] element of the local Wcs affine transform.
cd12 : pandas.Series: [1, 2] element of the local Wcs affine transform.
cd21 : pandas.Series: [2, 1] element of the local Wcs affine transform.
cd22 : pandas.Series: [2, 2] element of the local Wcs affine transform.

Returns:

raDecTuple : tuple: RA and dec conversion of x and y given the local Wcs. Returned units are in radians.

computeSkySeperation(ra1, dec1, ra2, dec2)¶

Compute the local pixel scale conversion.

Parameters:	ra1 : `pandas.Series` Ra of the first coordinate in radians. dec1 : `pandas.Series` Dec of the first coordinate in radians. ra2 : `pandas.Series` Ra of the second coordinate in radians. dec2 : `pandas.Series` Dec of the second coordinate in radians.
Returns:	dist : `pandas.Series` Distance on the sphere in radians.

difference(data1, data2, **kwargs)¶: Computes difference between functor called on two different ParquetTable objects

fail(df)¶

getSkySeperationFromPixel(x1, y1, x2, y2, cd11, cd12, cd21, cd22)¶

Compute the distance on the sphere from x2, y1 to x1, y1.

Parameters:

x1 : pandas.Series: X pixel coordinate.
y1 : pandas.Series: Y pixel coordinate.
x2 : pandas.Series: X pixel coordinate.
y2 : pandas.Series: Y pixel coordinate.
cd11 : pandas.Series: [1, 1] element of the local Wcs affine transform.
cd11 : pandas.Series: [1, 1] element of the local Wcs affine transform.
cd12 : pandas.Series: [1, 2] element of the local Wcs affine transform.
cd21 : pandas.Series: [2, 1] element of the local Wcs affine transform.
cd22 : pandas.Series: [2, 2] element of the local Wcs affine transform.

Returns:

Distance : pandas.Series: Arcseconds per pixel at the location of the local WC

multilevelColumns(data, columnIndex=None, returnTuple=False)¶

Returns columns needed by functor from multilevel dataset

To access tables with multilevel column structure, the MultilevelParquetTable or DeferredDatasetHandle need to be passed either a list of tuples or a dictionary.

Parameters:

data : MultilevelParquetTable or DeferredDatasetHandle
columnIndex (optional): pandas `Index` object: either passed or read in from DeferredDatasetHandle.
`returnTuple` : bool: If true, then return a list of tuples rather than the column dictionary specification. This is set to True by CompositeFunctor in order to be able to combine columns from the various component functors.

pixelScaleArcseconds(cd11, cd12, cd21, cd22)¶

Compute the local pixel to scale conversion in arcseconds.

Parameters:

cd11 : pandas.Series: [1, 1] element of the local Wcs affine transform in radians.
cd11 : pandas.Series: [1, 1] element of the local Wcs affine transform in radians.
cd12 : pandas.Series: [1, 2] element of the local Wcs affine transform in radians.
cd21 : pandas.Series: [2, 1] element of the local Wcs affine transform in radians.
cd22 : pandas.Series: [2, 2] element of the local Wcs affine transform in radians.

Returns:

pixScale : pandas.Series: Arcseconds per pixel at the location of the local WC

Navigation

ComputePixelScale¶