NAME

       mFixNaN - Replace a particular set of values in a FITS image with NaNs (or vice-versa)

SYNOPSIS

       mFixNaN [-d level] [-v NaN-value] in.fits out.fits [minblank maxblank]

DESCRIPTION

       Converts  NaNs  found  in the image to some other value (given by the user), or converts a
       range of supplied values into NaNs.

OPTIONS

       -d level
              Turn on debugging to the specified level (1-3)

       -v NaN-value
              Value to use in place of any NaNs

ARGUMENTS

       in.fits
              Input FITS image file

       out.fits
              Path of output FITS file.  To run in "count" mode without creating an output  file,
              use a dash ("-") for this argument.

       minblank maxblank
              If  the  "-v"  switch  is  not  used, mFixNaN will replace all pixel values between
              minblank and maxblank with NaN.

RESULT

       [struct stat="OK", rangeCount=rangeCount, nanCount=nanCount]

       rangeCount is the number of pixels that were found between minblank and maxblank, if  they
       were specified.  If not (i.e., NaNs were removed and replaced with value), nanCount is the
       number of NaNs removed.

MESSAGES

       OK     [struct stat="OK", rangeCount=rangeCount, nanCount=nanCount"]

       ERROR  No debug level given

       ERROR  Debug level string is invalid: level

       ERROR  Debug level string is invalid: level

       ERROR  Debug level string cannot be negative

       ERROR  No value given for NaN conversion

       ERROR  NaN conversion value string is invalid: 'NaN-value'

       ERROR  Invalid input file 'in.fits']

       ERROR  min blank value string is not a number

       ERROR  max blank value string is not a number

       ERROR  Image file in.fits missing or invalid FITS

       ERROR  FITS library error

EXAMPLES

       A FITS image with BITPIX -64 (double-precision floating point) was generated without using
       NaNs;  all  "blank" pixels are represented by very small negative numbers.  This can throw
       off initial attempts to display the image with a proper stretch, and does not  conform  to
       the FITS standard.  To replace all those "blank" pixels with NaNs:

       mFixNaN original.fits NaN.fits -4.61169e32 -4.61169e10
              [struct stat="OK", rangeCount=1321, nanCount=0]

       To convert those NaNs back into a single pixel value:

       mFixNaN -v -4.6e32 NaN.fits blankval.fits
              [struct stat="OK", rangeCount=0, nanCount=1321]

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.