# Provide an easy way to set Coord fields of a source catalog

XMLWordPrintable

#### Details

• Type: Improvement
• Status: Won't Fix
• Resolution: Done
• Fix Version/s: None
• Component/s:
• Labels:
• Story Points:
2
• Team:

#### Description

We sometimes need to set the coord fields of a source catalog, e.g. when fitting a new WCS or when studying an icSrc catalog (whose Coord field is not set). It would be nice to have a central, easily found way to do this. Right now we have the following as a static method of TanSipWcsTask, which works fine but is in a poor location:

  def updateSourceCoords(wcs, sourceList):  """Update coords in a collection of sources, given a WCS  """  if len(sourceList) < 1:  return  schema = sourceList[1].schema  srcCoordKey = afwTable.CoordKey(schema["coord"])  for src in sourceList:  src.set(srcCoordKey, wcs.pixelToSky(src.getCentroid())) 

The other direction is also useful for reference catalogs, though from a practical standpoint the only user is probably meas_astrom. Even so, I suggest that this be made publicly available in the same way. Again, this is presently a static method of FitTanSipWcsTask:

  def updateRefCentroids(wcs, refList):  """Update centroids in a collection of reference objects, given a WCS  """  if len(refList) < 1:  return  schema = refList[0].schema  coordKey = afwTable.CoordKey(schema["coord"])  centroidKey = afwTable.Point2DKey(schema["centroid"])  for refObj in refList:  refObj.set(centroidKey, wcs.skyToPixel(refObj.get(coordKey))) 

I hope this can remain Python code, but admit that the extra speed of C++ might come in handy in some cases. In any case, once the function is in a central location we can implement it in C++ if we find the need.

#### Activity

No builds found.
Russell Owen created issue -
Field Original Value New Value
Watchers Jim Bosch, Russell Owen [ Jim Bosch, Russell Owen ] Jim Bosch, John Swinbank, Russell Owen [ Jim Bosch, John Swinbank, Russell Owen ]
Assignee John Swinbank [ swinbank ]
Labels sciencepipelines
 Team Alert Production [ 10300 ]
 Link This issue relates to RFC-197 [ RFC-197 ]
 Link This issue relates to DM-6566 [ DM-6566 ]
Hide
Tim Jenness added a comment -

Where do we stand with this old ticket? Is it still useful to keep around?

Show
Tim Jenness added a comment - Where do we stand with this old ticket? Is it still useful to keep around?
Hide
Jim Bosch added a comment -

I don't think this was actually ever valid; SourceTable.updateCoords dates back to well before this ticket.  Either that or I've missed some subtle reason it couldn't be used for this use case.  In any case, I think this ticket is no longer useful.

Show
Jim Bosch added a comment - I don't think this was actually ever valid; SourceTable.updateCoords dates back to well before this ticket.  Either that or I've missed some subtle reason it couldn't be used for this use case.  In any case, I think this ticket is no longer useful.
 Resolution Done [ 10000 ] Status To Do [ 10001 ] Won't Fix [ 10405 ]

#### People

Assignee:
Unassigned
Reporter:
Russell Owen
Watchers:
Jim Bosch, John Parejko, John Swinbank, Russell Owen, Tim Jenness