CosmoloGUI Screenshots

This version June 2004. Check the web page for the latest version.

These screenshots show CosmoloGUI being used to look at the WMAP + other CMB+2dF chain available on the CosmoMC chains page.

First you will need to use the "Get Samples" GUI to find some samples files. In this case the WMAP + other CMB+2dF chain has been downloaded, unzipped (gunzip WMAPcmb2df.txt.gz) and put into the chains directory.

Click on "Add Samples File to List" to browse your filespace and find a samples file.
Since this samples files was produced using a pre March 2004 version of CosmoMC you will need to change the "Parameter Names" file. Click on "CMB.names" and choose from the list of files "H.names".
Since this file has already been thinned and burn-in removed, you can change the "No. to Burn" to 0, and the "Thin Factor" to 1.
Click on the "Load" button to load in the file.

It is often useful to look at a plot of probability against line number, as if burn-in has not been removed at all then this will be apparent (the -log(Likelihood) will decrease sharply as a function of line number).

You can change to plot something more interesting eg. by clicking on the "X" pull-down menu and selecting a parameter.

In general, comments and additional information are displayed in the matlab prompt window. In the above example, the 68 and 95 per cent limits are shown for the parameter plotted.

As in getdist, the properly marginalised likelihood is shown by the solid line, and the mean likelihood by the dotted line

Change the "Y" parameter to get a 2d plot.

You can change the type of plot from "Contours and Shading" to eg. just "Contours" using the pull down menu.

To allow different types of plot to be overlayed, you need to press the "Hold" button.

Sometimes it is useful to plot the positions of the samples on top of the contours to see how reliable the contours are.

Changing the "Z" axis to "Probability" gives you a 3d plot.

Press the "Rotate" button to make the 3d plot rotate about the default axis.

Press the "Save movie" button to create a rotating movie AVI file, eg. ready for including in powerpoint presentations. (low res mpg)

Sarah Bridle.