Re: [R] _: how to replace values in x by means in subgroups created in ...(not loops)

Re:_: how to replace values in x by means in subgroups created in ...(not loops) Thanks, below some code and reply: #_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_# #--- # my slow function with loops: # replace_x_by_locallyMean_x_4_0s_in_y.f(x,y) #-

Re: [R] how to replace values in x by means in subgroups created in ... (not loops)

Something like this? dataset <- data.frame(x = x, y = y) dataset$Group <- cumsum(c(0, diff(!is.na(dataset$y) & dataset$y == 0)) == 1) library(plyr) tmp <- ddply(subset(dataset, y == 0), .(Group), function(z){c(Mean = mean(z$x, na.rm = TRUE))}) result <- merge(dataset, tmp) result$Mean[is.na(resul