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.