Classes
class	InitialSkyWcsError

Functions
def	createInitialSkyWcs (visitInfo, detector, flipX=False)

def	createInitialSkyWcsFromBoresight (boresight, orientation, detector, flipX=False)

def	bboxFromIraf (irafBBoxStr)

def	getInstrument (instrumentName, registry=None)

def	setDottedAttr (item, name, value)

def	setDottedAttrs (item, attrs)

Function Documentation

◆ bboxFromIraf()

def lsst.obs.base.utils.bboxFromIraf ( irafBBoxStr )

Return a Box2I corresponding to an IRAF-style BBOX

[x0:x1,y0:y1] where x0 and x1 are the one-indexed start and end columns,
and correspondingly y0 and y1 are the start and end rows.

Definition at line 116 of file utils.py.

 def bboxFromIraf(irafBBoxStr):
     """Return a Box2I corresponding to an IRAF-style BBOX
  
     [x0:x1,y0:y1] where x0 and x1 are the one-indexed start and end columns,
     and correspondingly y0 and y1 are the start and end rows.
     """
  
     mat = re.search(r"^\[([-\d]+):([-\d]+),([-\d]+):([-\d]+)\]$", irafBBoxStr)
     if not mat:
         raise RuntimeError("Unable to parse IRAF-style bbox \"%s\"" % irafBBoxStr)
     x0, x1, y0, y1 = [int(_) for _ in mat.groups()]
  
     return geom.BoxI(geom.PointI(x0 - 1, y0 - 1), geom.PointI(x1 - 1, y1 - 1))
  
  

◆ createInitialSkyWcs()

def lsst.obs.base.utils.createInitialSkyWcs	(	visitInfo,
		detector,
		flipX = `False`
	)

Create a SkyWcs from the visit information and detector geometry.

A typical usecase for this is to create the initial WCS for a newly-read
raw exposure.


Parameters
----------
visitInfo : `lsst.afw.image.VisitInfo`
    Where to get the telescope boresight and rotator angle from.
detector : `lsst.afw.cameraGeom.Detector`
    Where to get the camera geomtry from.
flipX : `bool`, optional
    If False, +X is along W, if True +X is along E.

Returns
-------
skyWcs : `lsst.afw.geom.SkyWcs`
    The new composed WCS.

Raises
------
InitialSkyWcsError
    Raised if there is an error generating the SkyWcs, chained from the
    lower-level exception if available.

Definition at line 44 of file utils.py.

 def createInitialSkyWcs(visitInfo, detector, flipX=False):
     """Create a SkyWcs from the visit information and detector geometry.
  
     A typical usecase for this is to create the initial WCS for a newly-read
     raw exposure.
  
  
     Parameters
     ----------
     visitInfo : `lsst.afw.image.VisitInfo`
         Where to get the telescope boresight and rotator angle from.
     detector : `lsst.afw.cameraGeom.Detector`
         Where to get the camera geomtry from.
     flipX : `bool`, optional
         If False, +X is along W, if True +X is along E.
  
     Returns
     -------
     skyWcs : `lsst.afw.geom.SkyWcs`
         The new composed WCS.
  
     Raises
     ------
     InitialSkyWcsError
         Raised if there is an error generating the SkyWcs, chained from the
         lower-level exception if available.
     """
     if visitInfo.getRotType() != RotType.SKY:
         msg = (f"Cannot create SkyWcs from camera geometry: rotator angle defined using "
                f"RotType={visitInfo.getRotType()} instead of SKY.")
         raise InitialSkyWcsError(msg)
     orientation = visitInfo.getBoresightRotAngle()
     boresight = visitInfo.getBoresightRaDec()
     return createInitialSkyWcsFromBoresight(boresight, orientation, detector, flipX)
  
  

◆ createInitialSkyWcsFromBoresight()

def lsst.obs.base.utils.createInitialSkyWcsFromBoresight	(	boresight,
		orientation,
		detector,
		flipX = `False`
	)

Create a SkyWcs from the telescope boresight and detector geometry.

A typical usecase for this is to create the initial WCS for a newly-read
raw exposure.

Parameters
----------
boresight : `lsst.geom.SpherePoint`
    The ICRS boresight RA/Dec
orientation : `lsst.geom.Angle`
    The rotation angle of the focal plane on the sky.
detector : `lsst.afw.cameraGeom.Detector`
    Where to get the camera geomtry from.
flipX : `bool`, optional
    If False, +X is along W, if True +X is along E.

Returns
-------
skyWcs : `lsst.afw.geom.SkyWcs`
    The new composed WCS.

Raises
------
InitialSkyWcsError
    Raised if there is an error generating the SkyWcs, chained from the
    lower-level exception if available.

Definition at line 80 of file utils.py.

 def createInitialSkyWcsFromBoresight(boresight, orientation, detector, flipX=False):
     """Create a SkyWcs from the telescope boresight and detector geometry.
  
     A typical usecase for this is to create the initial WCS for a newly-read
     raw exposure.
  
     Parameters
     ----------
     boresight : `lsst.geom.SpherePoint`
         The ICRS boresight RA/Dec
     orientation : `lsst.geom.Angle`
         The rotation angle of the focal plane on the sky.
     detector : `lsst.afw.cameraGeom.Detector`
         Where to get the camera geomtry from.
     flipX : `bool`, optional
         If False, +X is along W, if True +X is along E.
  
     Returns
     -------
     skyWcs : `lsst.afw.geom.SkyWcs`
         The new composed WCS.
  
     Raises
     ------
     InitialSkyWcsError
         Raised if there is an error generating the SkyWcs, chained from the
         lower-level exception if available.
     """
     try:
         pixelsToFieldAngle = detector.getTransform(detector.makeCameraSys(PIXELS),
                                                    detector.makeCameraSys(FIELD_ANGLE))
     except lsst.pex.exceptions.InvalidParameterError as e:
         raise InitialSkyWcsError("Cannot compute PIXELS to FIELD_ANGLE Transform.") from e
     return makeSkyWcs(pixelsToFieldAngle, orientation, flipX, boresight)
  
  

◆ getInstrument()

def lsst.obs.base.utils.getInstrument	(	instrumentName,
		registry = `None`
	)

Return an instance of a named instrument.

If the instrument name not is qualified (does not contain a '.') and a
butler registry is provided, this will attempt to load the instrument using
Instrument.fromName. Otherwise the instrument will be imported and
instantiated.

Parameters
----------
instrumentName : string
    The name or fully-qualified class name of an instrument.
registry : `lsst.daf.butler.Registry`, optional
    Butler registry to query to find information about the instrument, by
    default None

Returns
-------
Instrument subclass instance
    The instantiated instrument.

Raises
------
RuntimeError
    If the instrument can not be imported, instantiated, or obtained from
    the registry.
TypeError
    If the instrument is not a subclass of lsst.obs.base.Instrument.

Definition at line 131 of file utils.py.

 def getInstrument(instrumentName, registry=None):
     """Return an instance of a named instrument.
  
     If the instrument name not is qualified (does not contain a '.') and a
     butler registry is provided, this will attempt to load the instrument using
     Instrument.fromName. Otherwise the instrument will be imported and
     instantiated.
  
     Parameters
     ----------
     instrumentName : string
         The name or fully-qualified class name of an instrument.
     registry : `lsst.daf.butler.Registry`, optional
         Butler registry to query to find information about the instrument, by
         default None
  
     Returns
     -------
     Instrument subclass instance
         The instantiated instrument.
  
     Raises
     ------
     RuntimeError
         If the instrument can not be imported, instantiated, or obtained from
         the registry.
     TypeError
         If the instrument is not a subclass of lsst.obs.base.Instrument.
     """
     if "." not in instrumentName and registry is not None:
         try:
             instr = Instrument.fromName(instrumentName, registry)
         except Exception as err:
             raise RuntimeError(
                 f"Could not get instrument from name: {instrumentName}. Failed with exception: {err}")
     else:
         try:
             instr = doImport(instrumentName)
         except Exception as err:
             raise RuntimeError(f"Could not import instrument: {instrumentName}. Failed with exception: {err}")
         instr = instr()
     if not isinstance(instr, Instrument):
         raise TypeError(f"{instrumentName} is not an Instrument subclass.")
     return instr
  
  
 #  TODO remove the impl in pipe_base? (NB this combines setDottedAtr AND the
 # handling in ConfigValueAction.__call__)

◆ setDottedAttr()

def lsst.obs.base.utils.setDottedAttr	(	item,
		name,
		value
	)

Set an instance attribute (like `setattr` but accepting hierarchical
names such as ``foo.bar.baz``) If the attribute can not be set as a string,
will attempt to set the attribute with the result of eval'ing the value.

Parameters
----------
item : obj
    Object whose attribute is to be set.
name : `str`
    Name of attribute to set.
value : obj
    New value for the attribute.

Notes
-----
For example if name is ``foo.bar.baz`` then ``item.foo.bar.baz``
is set to the specified value.

Raises
------
AttributeError
    If the item does not have a field specified by name that can be set.
RuntimeError
    If the value can not be set as a string or rendered by eval, or if
    there is an error setting the attribute with the rendered value.

Definition at line 179 of file utils.py.

 def setDottedAttr(item, name, value):
     """Set an instance attribute (like `setattr` but accepting hierarchical
     names such as ``foo.bar.baz``) If the attribute can not be set as a string,
     will attempt to set the attribute with the result of eval'ing the value.
  
     Parameters
     ----------
     item : obj
         Object whose attribute is to be set.
     name : `str`
         Name of attribute to set.
     value : obj
         New value for the attribute.
  
     Notes
     -----
     For example if name is ``foo.bar.baz`` then ``item.foo.bar.baz``
     is set to the specified value.
  
     Raises
     ------
     AttributeError
         If the item does not have a field specified by name that can be set.
     RuntimeError
         If the value can not be set as a string or rendered by eval, or if
         there is an error setting the attribute with the rendered value.
     """
     subitem = item
     subnameList = name.split(".")
     for subname in subnameList[:-1]:
         subitem = getattr(subitem, subname)
     try:
         setattr(subitem, subnameList[-1], value)
     except AttributeError:
         raise AttributeError(f"No field: {name!r}")
     except Exception:
         try:
             v = eval(value, {})
         except Exception:
             raise RuntimeError(f"Cannot render {value!r} as a value for {name!r}")
         try:
             setattr(subitem, subnameList[-1], v)
         except Exception as e:
             raise RuntimeError(f"Cannot set config. {name}={value!r}: {e}")
  
  

◆ setDottedAttrs()

def lsst.obs.base.utils.setDottedAttrs	(	item,
		attrs
	)

Definition at line 225 of file utils.py.

 def setDottedAttrs(item, attrs):
     for name, value in attrs:
         setDottedAttr(item, name, value)

Classes