ncgm2cgm: 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/ncgm2cgm - from package: ncl

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

On Debian possible default full paths are:

/usr/bin/ncgm2cgm - from package: ncl-ncarg

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

Error in other languages:
ncgm2cgm: bevel nie gevind nie
ncgm2cgm: comandă negăsită
ncgm2cgm: comando não encontrado
ncgm2cgm: commande introuvable
ncgm2cgm: command not found
ncgm2cgm: käsku ei ole
ncgm2cgm: không tìm thấy lệnh
ncgm2cgm: komanda nerasta
ncgm2cgm: Kommando nicht gefunden.
ncgm2cgm: kommandot finns inte
ncgm2cgm: komut yok
ncgm2cgm: nie znaleziono polecenia
ncgm2cgm: níor aimsíodh an t-ordú
ncgm2cgm: no se encontró la orden
ncgm2cgm: no s'ha trobat l'ordre
ncgm2cgm: opdracht niet gevonden
ncgm2cgm: parancs nem található
ncgm2cgm: perintah tidak ditemukan
ncgm2cgm: príkaz nenájdený
ncgm2cgm: příkaz nenalezen
ncgm2cgm: команда не найдена
ncgm2cgm: командата не е открита
ncgm2cgm: 命令找不到
ncgm2cgm: コマンドが見つかりません