Merge Master

Merge something that should have been on main

.fr-O4IA6O/WSRT pipeline/WSRTTools182/MSFieldCompress.py

-#!/usr/bin/env python
-#
-# $Id: MSFieldCompress.py,v 1.3 2008/04/21 21:09:41 schoenma Exp $
-#
-# Script: MSFieldCompress.py
-# Author: A.P. Schoenmakers (ASTRON)
-#
-# This script compresses the FIELD and SOURCE table of a Measurement Set.
-# It leaves only the unique entries in these tables and adapts the FIELD_ID
-# references in the MAIN table.
-# This is convenient if the observation was done using a mosaic
-# pattern such as A -> B -> C -> A -> B -> C etc. All these pointings
-# end up individually in the FIELD and SOURCE table. When converting the
-# MS to UVFits, this would lead to a large SU table in the UVFits
-# file. By compressing the list in the FIELD and SOURCE table beforehand, the
-# created SU table is much shorter. This makes it much easier to
-# collect all data related to a single pointing. 
-#
-# Usage: MSFieldCompress.py <MSName>
-#
-# IMPORTANT: The input MS will be adapted; reversing the process is not
-# possible! 
-#
-
-# This we need for commandline handling and file checking
-import os,sys
-
-# This we need for MS interfacing
-from pyrap.tables import *
-
-# Numpy has several methods for array comparison and index finding
-from numpy import *
-
-def MSFieldCompress(ms):
-
-    # Open the FIELD table.
-    field = table(ms.getkeyword('FIELD'),readonly=False,ack=False)
-    fieldname = field.name()
-    fieldrows = field.nrows()
-    if (fieldrows == 1):
-        print "Field table only has one row; nothing to do!"
-        sys.exit(0)
-
-    # The NAME column holds the names of the mosaicing position. Multiple
-    # entries can have the same NAME.
-    fieldnames = array(field.getcol("NAME"))
-    uniq_fieldname = list(set(fieldnames));
-    new_fieldrows = len(uniq_fieldname)
-    if (new_fieldrows == fieldrows):
-        print "FIELD table already contains unique entries only; nothing to do!"
-        sys.exit(0)
-        
-    print "Compressing FIELD subtable from "+str(fieldrows)+" to "+str(new_fieldrows)+" entries"
-
-    # old_index holds the current entries in the FIELD table, new_index will
-    # contain the indices of the remaining (unique) entries.
-    old_index = arange(len(fieldnames))
-    new_index = copy(old_index)
-    # Create a temporary compressed FIELD table, this will be copied into the 
-    # input MS later.
-    field.copy("TMP_FIELD",copynorows=True)
-    tmp_field = table("TMP_FIELD",readonly=False,ack=False)
-
-    # Check the SOURCE table.
-    source = table(ms.getkeyword('SOURCE'),readonly=False,ack=False)
-    sourcename = source.name()
-    sourcerows = source.nrows()
-    if (sourcerows != fieldrows and sourcerows > 0):
-        print "Number of entries in SOURCE table does not match that in FIELD table;"
-        print "Cannot proceed"
-        exit(1)
-
-    # Create a temporary source table
-    source.copy("TMP_SOURCE",copynorows=True)
-    tmp_source = table("TMP_SOURCE",readonly=False,ack=False)
-
-    # Create the array new_index that holds the new index for each entry
-    # in the FIELD table.
-    # Also, copy each unique name entry in the FIELD table to the temporary
-    # table. Also for SOURCE entries if there is a valid SOURCE table.
-    for index,uf in enumerate(uniq_fieldname):
-       match = where(fieldnames == uf)
-       new_index[match] = index
-       old_row = match[0][0] # First match
-       field.copyrows(tmp_field,startrowin=old_row,nrow=1)
-       if (sourcerows > 0):
-           tmp_field.putcell("SOURCE_ID",index,index)
-           source.copyrows(tmp_source,startrowin=old_row,nrow=1)
-           tmp_source.putcell("SOURCE_ID",index,index)
-
-    field.close()
-    del field
-    source.close()
-    del source
-    # Copy the compressed FIELD table to the input MS
-    tmp_field.flush()
-    tmp_field.copy(fieldname,deep=True)
-    tmp_field.close()
-    tabledelete("TMP_FIELD",ack=False)
-
-    # Copy the compressed SOURCE table to the input MS
-    tmp_source.flush()
-    tmp_source.copy(sourcename,deep=True)
-    tmp_source.close()
-    tabledelete("TMP_SOURCE",ack=False)
-
-    # Now adapt the FIELD_ID pointers in the MAIN table
-    field_id = ms.getcol("FIELD_ID")
-    tmp = copy(field_id)
-    for i in old_index:
-        tmp[field_id == i] = new_index[i]
-        
-    ms.putcol("FIELD_ID",tmp)
-    ms.flush()
-
-#
-# MAIN program starts here
-#
-if (len(sys.argv) == 2):
-    msname = sys.argv[1]
-    
-else:
-    print "Usage:"
-    print "\t"+sys.argv[0]+" <MS>"
-    print "\t  <MS> is required"
-    sys.exit(1)
-
-if (os.path.isdir(msname) == 0):
-    print "Could not find MS: "+msname
-    sys.exit(1)
-    
-ms = table(msname,readonly=False,ack=False)
-MSFieldCompress(ms)
-ms.close()
-print "Done"
-
-sys.exit(0)
-