########################################################################3
# task_immoments.py
#
#
# Copyright (C) 2008, 2009
# Associated Universities, Inc. Washington DC, USA.
#
# This script is free software; you can redistribute it and/or modify it
# under the terms of the GNU Library General Public License as published by
# the Free Software Foundation; either version 2 of the License, or (at your
# option) any later version.
#
# This library is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
# License for more details.
#
# You should have received a copy of the GNU Library General Public License
# along with this library; if not, write to the Free Software Foundation,
# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
#
# Correspondence concerning AIPS++ should be adressed as follows:
# Internet email: aips2-request@nrao.edu.
# Postal address: AIPS++ Project Office
# National Radio Astronomy Observatory
# 520 Edgemont Road
# Charlottesville, VA 22903-2475 USA
#
# <author>
# Shannon Jaeger (University of Calgary)
# </author>
#
# <summary>
# CASA task for finding moments along a specified axis of a
# multi-dimentional CASA image.
# contents
# </summary>
#
# <reviewed reviwer="" date="" tests="" demos="">
# </reviewed
# <etymology>
# immoments stands for image momemnts
# </etymology>
#
# <synopsis>
# task_immoments.py is a Python script providing an easy to use task
# for generating momements along a user specified axis on a CASA image.
# This is a time-honoured spectral-line analysis technique for discovering
# spectral line information.
#
# In this task, moment, refers to collapsing an axis of the image,
# the moment axis, to a single pixel.
#
# The various moments that can be calculated are described in detail
# at http://casa.nrao.edu/docs/casaref/image.moments.html#x59-590001.1.1
#
# </synopsis>
#
# <example>
# <srcblock>
# # The following code snippet find the 1-moments, intensity-weighted
# # coordinate, often used for finding velocity fields.
# immoments( 'axis='spec', imagename='myimage', moment=1, outfile='velocityfields' )
#
# # Finding the spectral mean, -1 moment, on a specified portion of the image.
# # The region used is defined by the box and stokes parameters
# immoments( imagename='myimage', axis='spec', stokes='I', box=[55,12,97,32], moment=-1 )
#
# # The following example uses a second file to use as a mask.
# # The 0-moments, integrated values, are created on clean.im, but
# # the mask is based on all the data in calibrated.im, all values
# # about the threshold 0.5 are used to create the mask.
#
# immoments( 'clean.image', axis='spec', mask='calibrated.im>0.5', outfile='mom_withmask.im' )
# </srblock>
# </example>
#
# <motivation>
# To provide a user-friendly method of calculating image moments.
# </motivation>
#
# <todo>
# </todo>
import os, sys, time
from taskinit import *
from stat import S_ISDIR, ST_MTIME, ST_MODE
from ialib import write_image_history
_rg = rgtool()
def immoments(
imagename, moments, axis, region, box, chans, stokes,
mask, includepix, excludepix, outfile, stretch
):
retValue=None
casalog.origin('immoments')
_myia = iatool()
_tmp_csys = None
try:
if (len(outfile) == 0):
raise Exception, "outfile must be specified"
_myia.dohistory(False)
# First check to see if the output file exists. If it
# does then we abort. CASA doesn't allow files to be
# over-written, just a policy.
if os.path.exists(outfile):
raise Exception, 'Output file, '+outfile+\
' exists. immoment can not proceed, please\n'\
'remove it or change the output file name.'
elif ( len( outfile ) == 1 ):
raise Exception, 'outfile is not specified but must be'
_myia.open(imagename)
_tmp_csys = _myia.coordsys()
reg = _rg.frombcs(csys=_tmp_csys.torecord(),
shape=_myia.shape(), box=box, chans=chans, stokes=stokes,
stokescontrol="a", region=region
)
if isinstance(axis, str):
axis = _tmp_csys.findaxisbyname(axis)
_tmp_csys.done()
outia = _myia.moments(
moments=moments, axis=int(axis), mask=mask,
region=reg, includepix=includepix,
excludepix=excludepix, outfile=outfile, drop=False,
stretch=stretch
)
created_images = _immoments_get_created_images(outia.name(), outfile)
created_images.append(outia)
try:
param_names = immoments.func_code.co_varnames[:immoments.func_code.co_argcount]
param_vals = [eval(p) for p in param_names]
method = sys._getframe().f_code.co_name
for im in created_images:
write_image_history(
im, method, param_names, param_vals, casalog
)
except Exception, instance:
casalog.post("*** Error \'%s\' updating HISTORY" % (instance), 'WARN')
return True
except Exception, instance:
casalog.post('*** Error *** ' + str(instance), 'SEVERE')
raise
finally:
_myia.done()
_rg.done()
if outia:
outia.done()
if _tmp_csys:
_tmp_csys.done()
def _immoments_get_created_images(out1name, outfile):
dirpath = os.path.dirname(out1name)
target_time = os.path.getmtime(out1name)
entries = (os.path.join(dirpath, fn) for fn in os.listdir(dirpath) \
if os.path.basename(fn).startswith(outfile) and os.path.isdir(fn))
entries2 = []
for path in entries:
# we must explicitly check for file existence, because file
# read before may have been deleted by another process
# CAS-11205
if os.path.exists(path):
entries2.append((os.stat(path), path))
entries3 = []
for stat, path in entries2:
if os.path.exists(path):
entries3.append((stat.st_mtime, path))
# reverse sort by time
zz = sorted(entries3)
zz.reverse()
created_images = []
for mdate, path in zz:
if mdate < target_time:
break
if os.path.exists(path) and path != out1name:
created_images.append(path)
return created_images