There may be some chance that a proper wavelet transform may help me with signal features extraction. I know R contains a number of packages implementing wavelett filters and/or transforms. Is there an implementation of a trous wavelet transform ? Thank you so much, Maura Alice Messenger ;-) chatti anche con gli amici di Windows Live Messenger e tutti i telefonini TIM! Vai su http://maileservizi.alice.it/alice_messenger/index.html?pmk=footer [[alternative HTML version deleted]]