SpacingBat3 [1] filed an orphan request for xgraph [2]: Right now the package seems vaguely outdated, it doesn't even point to the valid resources and `xgraph` needs a lot of patching anyway to even think about making it runnable. Debian folks have also moved towards gnuplot in their packages it seems: https://packages.debian.org/stable/net/ns2
[1] https://aur.archlinux.org/account/SpacingBat3/ [2] https://aur.archlinux.org/pkgbase/xgraph/
