pda-landscape: command not found

Have You tried accessing the binary with the full path?

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

[root@server ~]# echo $PATH

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/pda-landscape - from package: python-mlpy

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