R/writeFITSim16i.R

In FITSio: FITS (Flexible Image Transport System) Utilities

writeFITSim16i <-
function (X, file = 'R.fits', ...)
{
### Utility writes FITS image after converting to single integer words
### for more compact data files
###
### Takes:
  ## Multi-dimensional array: X
  ## Output FITS file: file
  ## Other options for writeFITSim.r (but not bscale or bzero!)
### Returns:
  ## Writes FITS file to disk
### Requires/Used by:
  ## Requires writeFITSim.r
###
### A. Harris, Univ. MD Astronomy, 4/22/08, 1/29/13
###
    ## Set scale and offset to use maximum range
    offset <- mean(range(X, na.rm=TRUE))
    X <- X - offset
    scale <- (2^16 - 2)/(2*max(X, na.rm=TRUE))
    X <- X*scale
    ## convert to integers
    X <- array(as.integer(X), dim = dim(X))
    ## Write data
    writeFITSim(X, file, type = "single", bscale = 1/scale,
        bzero = offset, ...)
}