pre2ncgm: 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 CentOS possible default full paths are:

/usr/bin/pre2ncgm - from package: ncl

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/pre2ncgm - from package: ncl-ncarg

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

Error in other languages:
pre2ncgm: bevel nie gevind nie
pre2ncgm: comandă negăsită
pre2ncgm: comando não encontrado
pre2ncgm: commande introuvable
pre2ncgm: command not found
pre2ncgm: käsku ei ole
pre2ncgm: không tìm thấy lệnh
pre2ncgm: komanda nerasta
pre2ncgm: Kommando nicht gefunden.
pre2ncgm: kommandot finns inte
pre2ncgm: komut yok
pre2ncgm: nie znaleziono polecenia
pre2ncgm: níor aimsíodh an t-ordú
pre2ncgm: no se encontró la orden
pre2ncgm: no s'ha trobat l'ordre
pre2ncgm: opdracht niet gevonden
pre2ncgm: parancs nem található
pre2ncgm: perintah tidak ditemukan
pre2ncgm: príkaz nenájdený
pre2ncgm: příkaz nenalezen
pre2ncgm: команда не найдена
pre2ncgm: командата не е открита
pre2ncgm: 命令找不到
pre2ncgm: コマンドが見つかりません