graph-slam: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/graph-slam - from package: mrpt-apps

You may install the required package with command apt-get install {package}

Error in other languages:
graph-slam: bevel nie gevind nie
graph-slam: comandă negăsită
graph-slam: comando não encontrado
graph-slam: commande introuvable
graph-slam: command not found
graph-slam: käsku ei ole
graph-slam: không tìm thấy lệnh
graph-slam: komanda nerasta
graph-slam: Kommando nicht gefunden.
graph-slam: kommandot finns inte
graph-slam: komut yok
graph-slam: nie znaleziono polecenia
graph-slam: níor aimsíodh an t-ordú
graph-slam: no se encontró la orden
graph-slam: no s'ha trobat l'ordre
graph-slam: opdracht niet gevonden
graph-slam: parancs nem található
graph-slam: perintah tidak ditemukan
graph-slam: príkaz nenájdený
graph-slam: příkaz nenalezen
graph-slam: команда не найдена
graph-slam: командата не е открита
graph-slam: 命令找不到
graph-slam: コマンドが見つかりません