Source Code for Module multidrizzle.mdzhandler

 1  # 
 2  #   Authors: Warren Hack, Ivo Busko, Christopher Hanley 
 3  #   Program: mdzhandler.py 
 4  #   Purpose: Module that handles the MDRIZTAB reference file. 
 5  from __future__ import division # confidence high 
 6   
 7  import pyfits 
 8  from pytools import fileutil 
 9   
10   
11 -def getMultidrizzleParameters(files): 
12      """ Gets entry in MDRIZTAB where task parameters live. 
13          This method returns a record array mapping the selected 
14          row. 
15      """ 
16   
17      # Get the MDRIZTAB table file name from the primary header. 
18      # It is gotten from the first file in the input list. No 
19      # consistency checks are performed. 
20      _fileName = files[0] 
21      _header = fileutil.getHeader(_fileName) 
22      if _header.has_key('MDRIZTAB'): 
23          _tableName = _header['MDRIZTAB'] 
24      else: 
25          raise KeyError, "No MDRIZTAB found in file " + _fileName 
26   
27      _tableName = fileutil.osfn(_tableName) 
28   
29      # Now get the filters from the primary header. 
30      _filters = fileutil.getFilterNames(_header) 
31   
32      # Open MDRIZTAB file. 
33      try: 
34          _mdriztab = pyfits.open(_tableName) 
35      except: 
36          raise IOError,"MDRIZTAB table '%s' not valid!" % _tableName 
37   
38      # Look for matching rows based on filter name. If no 
39      # match, pick up rows for the default filter. 
40      _rows = _getRowsByFilter(_mdriztab, _filters) 
41      if _rows == []: 
42          _rows = _getRowsByFilter(_mdriztab, 'ANY') 
43   
44      # Now look for the row that matches the number of images. 
45      # The logic below assumes that rows for a given filter 
46      # are arranged in ascending order of the 'numimage' field. 
47      _nimages = len(files) 
48      _row = 0 
49      for i in _rows: 
50          _numimages = _mdriztab[1].data.field('numimages')[i] 
51          if _nimages >= _numimages: 
52              _row = i 
53      print '- MDRIZTAB: MultiDrizzle parameters read from row %s.'%(_row+1) 
54   
55      mpars = _mdriztab[1].data[_row] 
56      _mdriztab.close()  
57   
58      return mpars 
59   
60 -def _getRowsByFilter(table, filters): 
61      rows = [] 
62      for i in xrange(table[1].data.shape[0]): 
63          _tfilters = table[1].data.field('filter')[i] 
64          if _tfilters == filters: 
65              rows.append(i) 
66      return rows 
67