search for: samp5

Dear all, suppose I have a bi-variate function f(x,y), I want to find the maxima. I define x and y vector, and get matrix z=f(x,y). how can I get which (x0,y0) makes z become the maxima? I can do two loops to get the x0 and y0, but I think there may exist a function to do this.

...0 vectors, each vector has 7 elements. samp <- lapply(1:100, function(i) sample(LETTERS)) samp2 <- lapply(samp2, "[", 1:7) How can I select the 26 plots from 'data' using 'samp'? samp3 <- sample(LETTERS, 7) samp4 <- subset(data, plot %in% samp3) # this works samp5 <- subset(data, plot %in% samp2[[1]]) # this works as well, but I used a for loop to get it to select 7 plots 100 times. for (i in nrow(samp2)) { samp6 <- subset(data, plot %in% samp2[[i]]) } # this doesn't work Am I missing something, or is there a better solution? Thanks. Kang...