Hello, Couldn't think of a better subject line. Rather than a matrix like x,y ..,.. .,.. I have a matrix like x,y,n, ..,..,.., ..,..,.. and so on. Also, sum(n) is roughly few hundred million. The number of rows is <1MM Are they routines to fit a 2d kde estimate to data provided in this form? I can sample from the data according to weights given by 'n' but i am curious if there is something that can use all the data when given a structure of this form. Regards Saptarshi [[alternative HTML version deleted]]