NAME

       mDAG - Create a Directed Acyclic Graph (DAG) for Pegasus

SYNOPSIS

       mDAG survey band objstr width height cdelt workdir workurlbase [urlbase]

       mDAG -h survey band hdrfile workdir workurlbase [urlbase]

DESCRIPTION

       mDAG  creates  an XML-based Directed Acyclic Graph (DAG) that specifies  "jobs" or Montage
       modules to be run to produce a  mosaic,   "files"  to  be  consumed  or  generated  during
       processing  (input,  intermediate,  and output files), and "dependencies" between jobs and
       files that imply an order in which jobs should be run.  In this "abstract graph",  logical
       names  are assigned to jobs and files.  The abstract graph is intended to be an input to a
       job scheduler, such as Pegasus in the Chimera Virtual Data System.

OPTIONS

       -h

              Output mosaic is based on a header file  rather  than  explicit  object  name  (for
              location), sizes and scale.

ARGUMENTS

       survey

              mDAG  has  custom code for dealing with surveys (e.g. DSS) where we know we have to
              use the slower mProject module rather than mProjectPP.

       band

              mDAG also has custom code for the 2MASS survey where Montage scales the data  to  a
              project-specified magnitude zero point by band (J,H,K).

       objstr

              Object name, resolved through NED/SIMBAD for sky location.

       width/height

              Size of the image in degrees.

       cdelt

              Pixel scale in degrees.

       hdrfile

              Instead  of  objstr,  width, height, and cdelt the user an provide a pre-built FITS
              header.

       workdir

              There are a collection of files the processing will need ane  which  mDAG  creates.
              The user needs to create a location for this and give it to mDAG.

       workurlbase

              While working, some files in the workspace are accessed via URL.  Again, this needs
              to be set up by the user beforehand.

       urlbase

              Optionally, results can be made URL-accessible if this parameter is given.

RESULT

       If successful, the workspace will be populated with severeal tables and with the "dag.xml"
       file to be given to the workflow manager.

MESSAGES

       ERROR  Error opening debug file

       ERROR  Error opening header template file

       ERROR  Error opening big header template file

       ERROR  Error opening image list

       ERROR  Error opening working file list for write

       ERROR  Error opening working file list for read

       ERROR  Error opening parent list

       ERROR  Error opening sorted parent list

       ERROR  Bad template: file

       ERROR  Output wcsinit() failed.

       ERROR  general error message

       ERROR  No return message from object lookup.

       ERROR  Invalid location specification or object name.

       ERROR  Can't find RA in lookup return.

       ERROR  Can't find Dec in lookup return.

       ERROR  Couldn't find host hostname

       ERROR  Couldn't create socket()

       ERROR, msg=
              hostname: connect failed.

EXAMPLES

       mDAG     2mass     j     m51     0.5     0.5     0.00277778     m51work    http://montage-
       web.ipac.caltech.edu/workspace/m51
              [struct stat="OK", id="20150904_095958_21631"]

BUGS

       The drizzle algorithm has been implemented but has not been tested in this release.

       If a header template contains  carriage  returns  (i.e.,  created/modified  on  a  Windows
       machine),  the cfitsio library will be unable to read it properly, resulting in the error:
       [struct stat="ERROR", status=207, msg="illegal character in keyword"]

       It is best for the background correction algorithms if the area described  in  the  header
       template  completely encloses all of the input images in their entirety. If parts of input
       images are "chopped off" by  the  header  template,  the  background  correction  will  be
       affected.  We  recommend  you  use  an expanded header for the reprojection and background
       modeling steps, returning to the originally desired header size for the final  coaddition.
       The default background matching assumes that there are no non-linear background variations
       in the individual images (and therefore in the  overlap  differences).  If  there  is  any
       uncertainty  in  this  regard, it is safer to turn on the "level only" background matching
       (the "-l" flag in mBgModel.

COPYRIGHT

       2001-2015 California Institute of Technology, Pasadena, California

       If your research  uses  Montage,  please  include  the  following  acknowledgement:  "This
       research  made use of Montage. It is funded by the National Science Foundation under Grant
       Number ACI-1440620, and was previously  funded  by  the  National  Aeronautics  and  Space
       Administration's  Earth Science Technology Office, Computation Technologies Project, under
       Cooperative Agreement Number  NCC5-626  between  NASA  and  the  California  Institute  of
       Technology."

       The  Montage  distribution  includes an adaptation of the MOPEX algorithm developed at the
       Spitzer Science Center.