> I don't understand your point here about the additive > constant.
I took into account the additive constant "1" because of the unfeasibility of log(0). However, this transformation is useless, because it maintains the zero values! How could I transform my data to make a normalisation? Duccio -- * To post a message to the list, send it to [EMAIL PROTECTED] * As a general service to the users, please remember to post a summary of any useful responses to your questions. * To unsubscribe, send an email to [EMAIL PROTECTED] with no subject and "unsubscribe ai-geostats" followed by "end" on the next line in the message body. DO NOT SEND Subscribe/Unsubscribe requests to the list * Support to the list is provided at http://www.ai-geostats.org