ask-compare-time-series: 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/ask-compare-time-series - from package: ask

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

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