Sage provides a unified interface to the best computational software. This is accomplished using both C-libraries (see C/C++ Library Interfaces) and interpreter interfaces, which are implemented using pseudo-tty’s, system files, etc. This chapter is about these interpreter interfaces.
Each interface requires that the corresponding software is installed on your computer. Sage includes GAP, PARI, Singular, and Maxima, but does not include Octave (very easy to install), MAGMA (non-free), Maple (non-free), or Mathematica (non-free).
There is overhead associated with each call to one of these systems. For example, computing 2+2 thousands of times using the GAP interface will be slower than doing it directly in Sage. In contrast, the C-library interfaces of C/C++ Library Interfaces incur less overhead.
In addition to the commands described for each of the interfaces below, you can also type e.g., %gap, %magma, etc., to directly interact with a given interface in its state. Alternatively, if X is an interface object, typing X.interact() allows you to interact with it. This is completely different than X.console() which starts a complete new copy of whatever program X interacts with. Note that the input for X.interact() is handled by Sage, so the history buffer is the same as for Sage, tab completion is as for Sage (unfortunately!), and input that spans multiple lines must be indicated using a backslash at the end of each line. You can pull data into an interactive session with X using sage(expression).
The console and interact methods of an interface do very different things. For example, using gap as an example:
The console function is very useful on occasion, since you get the exact actual program available (especially useful for tab completion and testing to make sure nothing funny is going on).