easy_plot: 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/easy_plot - from package: qtoctave

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

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