---
name: "mRotate"
section: "1"
platform: "linux"
package: "montage"
version: "6.1+dfsg-1+b1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/mRotate"
---

# mRotate(1)

Rotate a FITS image by an arbitrary angle

## NAME

mRotate - Rotate a FITS image by an arbitrary angle

## SYNOPSIS

mRotate \[-d *level*\] \[-s *statusfile*\] \[-r *rotang*\] in.fits out.fits \[*ra dec xsize* \[*ysize*\]\]

## DESCRIPTION

Rotates a FITS image by an arbitrary angle.  This module is meant for quick-look only; it is not flux conserving.

## OPTIONS

- \-d *level*

  Print out additional debugging information (*level* can be 1-3)

- \-s *statusfile*

  Output and errors are written to *statusfile* instead of stdout.

- \-r *rotang*

  Provide an angle (in degrees) to rotate the image.

## ARGUMENTS

- in.fits

  Input FITS image.

- out.fits

  Path to output (rotated) FITS image.

- ra dec xsize

  Center location and width (in degrees) of output image - optional.  By default, entire input image area will be included in output image.

- ysize

  Height (in degrees) of output image, if a new center location and width are provided.  Optional - defaults to *xsize*.

## RESULT

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

Output file will contain the same image as the input file, but rotated by *rotang* degrees.  If a new center location and width were provided, the output image will be the "subimage" covering that area.

## MESSAGES

- OK

  \[struct stat="OK"\]

- ERROR

  No status file name given

- ERROR

  Cannot open status file: *statusfile*

- ERROR

  No rotation angle given

- ERROR

  Rotation angle string is invalid: '*rotang*'

- ERROR

  No debug level given

- ERROR

  Debug level string is invalid: '*level*'

- ERROR

  Debug level value cannot be negative

- ERROR

  Invalid input file '*in.fits*'

- ERROR

  Invalid output file '*out.fits*'

- ERROR

  Center RA string (*ra*) cannot be interpreted as a real number

- ERROR

  Center Dec string (*dec*) cannot be interpreted as a real number

- ERROR

  X size string (*xsize*) cannot be interpreted as a real number

- ERROR

  Y size string (*ysize*) cannot be interpreted as a real number

- ERROR

  Invalid 'x' size

- ERROR

  Invalid 'y' size

- ERROR

  Location is off image

- ERROR

  No pixels match output area

- ERROR

  No pixels match input area

- ERROR

  wcsinit() failed

- ERROR

  Image file *in.fits* missing or invalid FITS

- ERROR

  *FITS library error*

## EXAMPLES

- $ mRotate -r 90 in.fits out.fits

  \[struct stat="OK"\]

## 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.