Run atlas

This document will tell you how to start running atlas after you have done Download and Install. These instructions work best for the latest version.

Get atlas running

Let’s say you compiled the software in a directory atlasofliegroups, or perhaps you put a pre-compiled binary there. Use your terminal to navigate into that directory. It should contain the executable files Fokko and atlas, and subdirectories “messages” (help files for Fokko) and “atlas-scripts” (auxiliary and help files for atlas).

Once you are there, depending on your setting, do either:

./atlas --path=atlas-scripts

or:

atlas --path=atlas-scripts

You should then see something like this:

This is 'atlas' (version 0.6, axis language version 0.9),
the Atlas of Lie Groups and Representations interpreter,
compiled on Jan 19 2016 at 02:21:55.   http://www.liegroups.org/
atlas>

Alternatively, you can cd into the atlas-scripts folder, then do:

../atlas

Load scripts

The folder atlas-scripts includes scripts, like “basics.at”, that define a collection of functions complementing the primitive functions built into atlas.

Assuming you are in the atlas environment (when you see atlas> in your terminal), here is how to load some scripts. For example, to load the file “basic.at” do:

atlas> <basic

You will see atlas output:

Starting to read from file 'atlas-scripts//basic.at'.
Added definition [12] of #: (int->[int])
Added definition [13] of #: (bool->int)
...

The symbol “<” means read a file. If this doesn’t work, please see Trouble Shooting. Also, there is a video explaining how to launch atlas so that it finds the necessary .at files.

Once this is working, you can and should load other files. Load “all.at” to get a recommended set of files:

atlas> <all
[... some atlas output ...]
atlas>

To check if readline (command completion, recalling previous commands, etc.) is working, hit TAB on your keyboard twice. You should see something like:

atlas>
Display all 902 possibilities? (y or n)

This indicates that command completion is working. Now do a few simple commands:

atlas> 1+1
Value: 2
atlas> set G=SL(2,R)
Identifier G: RealForm
atlas> print_block(trivial (G))
Parameter defines element 2 of the following block:
0:  0  [i1]  1   (2,*)  *(x=0,lam=rho+  [0], nu=  [0]/1)  e
1:  0  [i1]  0   (2,*)  *(x=1,lam=rho+  [0], nu=  [0]/1)  e
2:  1  [r1]  2   (0,1)  *(x=2,lam=rho+  [0], nu=  [1]/1)  1^e

Congratulations! Now you have atlas working on your machine! Proceed to Tutorial for some examples of what you can do with atlas.

Quit atlas

Just type quit :)