Hello every body so I am writing the FCM algorithm in R, but I am wondring about the efficiency, When calculating the centers using the formula http://r.789695.n4.nabble.com/file/n3024803/ComputeCenters.png where here each X_i is a vector and U_ij are in a matrix, in other words I want to multiply each vector in X by a weight and then sum them up and calculate the mean. Thank you in advance for your help -- View this message in context: http://r.789695.n4.nabble.com/Calculate-the-weithed-mean-of-a-matrix-tp3024803p3024803.html Sent from the R help mailing list archive at Nabble.com.