sudo apt-get install ploticus
I believe the command for fedora is (as root):
yum install -y pl
For other OSes, download the software from the ploticus homepage:
http://ploticus.sourceforge.net/doc/download.html
Under ubuntu, the executable is called `ploticus'. If your install is called something else (eg., under Fedora it is called `pl'), then you'll need to edit your BLDdir/results/Makefile and change the PLOT macro to the correct name and path. You may also need to set where to find the ploticus prefab files. For instance, under Fedora I had to:
export PLOTICUS_PREFABS=/usr/share/ploticus