psscale: 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/psscale - from package: GMT

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

On Debian possible default full paths are:

/usr/lib/gmt/bin/psscale - from package: GMT

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

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