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Display Overview

Display Overview

You can change what the pipeline display system shows you and how it displays it by editing the disp.dat file, either directly or by using the oracdisp utility.

The default displays should be fine for most people. These are described here. The main reason why you'd want to change anything from the defaults at the moment is that when plotting a spectrum, the display system will autoscale, which you don't want to do if there's a large spike or other anomoly in the data. See "Changing the plotting scales" below for more details.

Generally, two windows are used to show you data as soon as possible after it comes off the array; one GAIA window, which shows you an image containg the data, and a KAPPA view window which shows histograms, extracted spectra and the like.

A similar two windows are used to show you more reduced data to display intermediate results and show you how well you're accumulating your signal to noise ratio etc. A GAIA window shows you the current group file image - ie the sky subtracted frame, or the difference of the main beam and offset pairs aquired so far. A KAPPA window is then used to show you the divided by standard and flux calibrated spectra.

Changing the plotting scales

The pipeline display system is controlled by a text file called disp.dat, which resides in your $ORAC_DATA_OUT directory. You can edit this file manually with your favourite text editor, or you can use the oracdisp utility.

The disp.dat file contains one line for each type of data that is to be displayed, specifying the file type that this refers to, the plotting tool to use and various parameters of the plot - ie axis scales, autoscaling etc. One important thing to remember is that the display system allways works in array co-ordinates, ie. x is wavelength, y is along the slit, and z is the data value.

To turn off autoscaling of your spectral plots:

  • Go either to the xterm where you launched oracdr from, or get a new xterm and run oracdr_cgs4 in it.
  • run oracdisp
  • Select the line for the type of plot you wish to change. This will probably be DBS for the divided by standard spectra, or FC for the flux calibrated spectra. Double-Click on the appropriate line in the lower pane of the oracdisp window. You may have to scroll down using the scrollbar to find the line you want.
  • In the upper portion of the oracdisp window, find the Z: line and click the button next to "Set" to go from autoscale to set mode, and change the zmin and zmax values to the axes range you would like displayed.
  • Click the "Modify" button at the bottom of the top pane of the oracdisp window.
  • Click the "Configure" button at the bottom of the oracdisp window.
The new settings will take effect next time a spectrum of that type is displayed, which if you're still oberving the same group will be when the next pair of observations is complete.

Contact: Tom Kerr. Updated: Wed Oct 6 11:54:13 HST 2004

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