lsst.meas.extensions.piff gbf5cecdb8a+43cb4dbb13
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Public Member Functions | Public Attributes | Protected Member Functions | Protected Attributes | Static Protected Attributes | List of all members
lsst.meas.extensions.piff.wcs_wrapper.UVWcsWrapper Class Reference
Inheritance diagram for lsst.meas.extensions.piff.wcs_wrapper.UVWcsWrapper:

Public Member Functions

 __init__ (self, pix_to_field, origin=None, world_origin=None)
 
 origin (self)
 
 world_origin (self)
 

Public Attributes

 u0
 
 x0
 

Protected Member Functions

 _xyTouv (self, x, y, color=None)
 
 _uvToxy (self, u, v, color)
 
 _posToWorld (self, image_pos, color=None)
 
 _local (self, image_pos, color=None)
 
 _newOrigin (self, origin, world_origin)
 

Protected Attributes

 _pix_to_field
 
 _origin
 
 _world_origin
 
 _mapping
 
 _color
 
 _rad_to_arcsec
 

Static Protected Attributes

float _rad_to_arcsec = 206264.80624709636
 

Detailed Description

Wrap a `lsst.afw.geom.TransformPoint2ToPoint2[2->2]` in a GalSim WCS.

Parameters
----------
pix_to_field : `lsst.afw.geom.TransformPoint2ToPoint2[2->2]`
    Transform to wrap.  Most likely PIXELS -> FIELD_ANGLE, but other 2D ->
    2D transforms should be possible.
origin : `galsim.PositionD`, optional
    Origin in image coordinates.
world_origin : `galsim.PositionD`, optional
    Origin in world coordinates.

Notes
-----

GalSim EuclideanWCS assumes
    u = ufunc(x-x0, y-y0) + u0
    v = vfunc(x-x0, y-y0) + v0
where u,v are world (likely field angles), and (x, y) are pixels.
GalSim also assumes that origin = x0, y0 and world_origin = u0, v0.
I might have naively thought that uv(origin) == world_origin, but
that appears to not be required. So we're just going to leave both
free.

Member Function Documentation

◆ _local()

lsst.meas.extensions.piff.wcs_wrapper.UVWcsWrapper._local ( self,
image_pos,
color = None )
protected
Compute local Jacobian WCS.

Parameters
----------
image_pos : galsim.PositionD
    Image position at which to compute local WCS.
color : ndarray
    Color to use in transformation.  Unused currently.

Returns
-------
local : galsim.JacobianWCS
    Local linear approximation to WCS.

◆ _newOrigin()

lsst.meas.extensions.piff.wcs_wrapper.UVWcsWrapper._newOrigin ( self,
origin,
world_origin )
protected
Return a new UVWcsWrapper with new origins.

Parameters
----------
origin : `galsim.PositionD`, optional
    Origin in image coordinates.
world_origin : `galsim.PositionD`, optional
    Origin in world coordinates.

Returns
-------
ret : `UVWcsWrapper`
    Transformed WCS.

◆ _posToWorld()

lsst.meas.extensions.piff.wcs_wrapper.UVWcsWrapper._posToWorld ( self,
image_pos,
color = None )
protected
Convert image coordinate to world coordinate.

Parameters
----------
image_pos : galsim.PositionD
    Image coordinate.
color : ndarray
    Color to use in transformation.  Unused currently.

Returns
-------
world_pos : galsim.PositionD
    World coordinate.

◆ _uvToxy()

lsst.meas.extensions.piff.wcs_wrapper.UVWcsWrapper._uvToxy ( self,
u,
v,
color )
protected
Convert world coordinates to image coordinates.

Parameters
----------
u, v : ndarray
    World coordinates.
color : ndarray
    Color to use in transformation.  Unused currently.

Returns
-------
x, y : ndarray
    Image coordinates.

◆ _xyTouv()

lsst.meas.extensions.piff.wcs_wrapper.UVWcsWrapper._xyTouv ( self,
x,
y,
color = None )
protected
Convert image coordinates to world coordinates.

Parameters
----------
x, y : ndarray
    Image coordinates.
color : ndarray
    Color to use in transformation.  Unused currently.

Returns
-------
u, v : ndarray
    World coordinates.

◆ origin()

lsst.meas.extensions.piff.wcs_wrapper.UVWcsWrapper.origin ( self)
The image coordinate position to use as the origin.

◆ world_origin()

lsst.meas.extensions.piff.wcs_wrapper.UVWcsWrapper.world_origin ( self)
The world coordinate position to use as the origin.

The documentation for this class was generated from the following file: