Starting GPItv

GPItv can be started from a script or from the IDL command-line prompt. Start IDL and type


It will display a default 2-d image.

To display an array that is in memory, pass its name to GPItv like this:

GPItv, array_name [, options]

where array_name is a two- or three-dimensional array to be displayed.

Similarly, to pass a FITS filename to GPItv, use the command:

GPItv, "fitsfile_name" [, options]

where fitsfile_name is a string (enclosed in quotes) containing the name of the FITS file (including extension) to be read. If the filename has a “.gz” extension, it will be treated as a gzip compressed file and be automatically decompressed before being read.

For instance, the command

GPItv, 'test.fits'

will display the file ‘test.fits’ if it exists in the current directory.

GPItv can be started from a script or from the IDL command-line prompt. If starting from within a script, you may wish to specify the “/block” option to pause the script while the user works with GPItv, or else use Multi-Session mode to allow concurrent execution.

Quick Overview

Figure 1: Overview of the main GPItv window.

In addition to menu functions and mouse modes described below, GPItv has several functions directly available from the main window:

  • A status area which displays the most important identification header information (such as keywords filename, dateobs,…) and current cursor position and related pixel intensity;
  • color map contrast and brightness
  • pan windows to view a zoomed region around the cursor. The mouse can be used to drag the image-view box around, or you can recenter by clicking in the main window.
  • a multi-plane slice slider available for data-cubes
  • choice of available units (depending on pipeline processing)
  • box for choice of mouse modes