frequencies: 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/lib/fastdnaml/bin/frequencies - from package: fastdnaml

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

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