fftw-wisdom-to-conf: 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/fftw-wisdom-to-conf - from package: fftw

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

On Debian possible default full paths are:

/usr/bin/fftw-wisdom-to-conf - from package: libfftw3-bin

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

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