isochore plots GC content over a sequence. It is intended for large sequences such as complete chromosomes or large genomic contigs, although interesting results can also be obtained from shorter sequences.

Here is a sample session with isochore. This reads yeast chromosome 3 from a remote web server, so the sequence reading may take a little time:

% isochore
Input sequence: tgb:scchriii
Output file [scchriii.iso]:
click here for result

Mandatory qualifiers:

[-sequence] (sequence)

Sequence USA.

[-out] (outfile)

Output filename.

-graph (xygraph)

Graph type.

Optional qualifiers:

-window (integer)

Window size.

-shift (integer)

Shift increment.