---
name: "mAddExec"
section: "1"
platform: "linux"
package: "montage"
version: "4.0+dfsg-3+b3"
release: "Debian 9 (Stretch)"
platforms: ["linux"]
url: "https://new.carta.tech/mAddExec"
---

# mAddExec(1)

Create a mosaic from images already in the same projection

## NAME

mAddExec - Create a mosaic from images already in the same projection

## SYNOPSIS

mAddExec \[-p *imgdir*\] \[-n(o-areas)\] \[-a mean\|median\] \[-e(xact-size)\] \[-d *level*\] \[-s *statusfile*\] \[-x *TilesSizeAxis0*\] \[-y *TileSizeAxis1*\] \[-o *OverlapAxis0*\] \[-q *OverlapAxis1*\] images.tbl template.hdr tiledir out.fits

## DESCRIPTION

Builds a series of outputs (which together make up a tiled output) through multiple executions of the mAdd modules.

## OPTIONS

- \-p *imgdir*

  Specifies path to directory containing reprojected images.  If the -p switch is not included, mAdd will look for the input images in the current working directory.

- \-n

  Co-addition ignores weighting by pixel areas and performs coaddition based only on pixel postions. Will not output an area image for the output image.

- \-a *type*

  Select type of averaging to be done on accumulated pixel values (either mean or median).

- \-e

  Enables exact size mode. The output image will match the header template exactly, instead of shrinking the output to fit the data.

- \-d *level*

  Turns on debugging to the specified level (1-3).

- \-s *statusfile*

  mAdd output and errors will be written to *statusfile* instead of stdout.

## ARGUMENTS

- images.tbl

  ASCII table (generated by mImgtbl) containing metadata for all images to be coadded.

- template.hdr

  FITS header template to be used in generation of output FITS

- tiledir

  Directory to contain output tile images and header templates

- out.fits

  Prefix for output tile images

## RESULT

If successful, mAddExec creates a set of FITS tiles covering the area described in **template.hdr, as well as matching "tiled" header files for each output tile.**

## MESSAGES

- OK

  \[struct stat = "OK", time=*time*\]

- ERROR

  MPI initialization failed

- ERROR

  Invalid argument for -x flag

- ERROR

  Invalid argument for -y flag

- ERROR

  Invalid argument for -o flag

- ERROR

  Invalid argument for -q flag

- ERROR

  Invalid argument for -a flag

- ERROR

  Cannot open status file: *statusfile*

- ERROR

  command line option was not integer

- ERROR

  option cannot be negative

- ERROR

  Invalid image metadata file: *filename*

- ERROR

  Need columns: cntr,fname, crpix1, crpix2, cdelt1, cdelt2, naxis1, naxis2, crval1, crval2 in image list

- ERROR

  Memory allocation failed

- ERROR

  Too many open files

- ERROR

  Input wcsinit() failed.

- ERROR

  Failed to allocate enough memory for output arrays

- ERROR

  Bad WCS in header template.

- ERROR

  Template file not found.

- ERROR

  *FITS library error*

- ERROR

  *general error message*

## EXAMPLES

The following example runs **mAddExec** on this set of images, generating a set of tiles conforming to the size and overlap specified on the command line:

- $ mAddExec -p proj -x 1000 -y 1000 images.tbl template.hdr tiles tile.fits

  \[struct stat="OK", mTileHdr\_count=4, mTileHdr\_failed=0, mTileHdr\_warning=0, mAdd\_count=4, mAdd\_failed=0, mAdd\_warning=0, time=8\]

- $ ls tiles

  tile\_0\_0.hdr

  tile\_0\_0.fits

  tile\_0\_0\_area.fits

  tile\_0\_1.hdr

  tile\_0\_1.fits

  tile\_0\_1\_area.fits

  tile\_1\_0.hdr

  tile\_1\_0.fits

  tile\_1\_0\_area.fits

  tile\_1\_1.hdr

  tile\_1\_1.fits

  tile\_1\_1\_area.fits

## 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.