search for: shortxy

...d.grid(1:10, 1:10) # Define a matrix ofvalues mat <- matrix(log(xy100[,1]) * log(xy100[,2])+1, ncol = 10)/2 #Plot some the matrix with image and the same data as xy plot: par(mfrow = c(2,2)) image(mat) plot(xy100, cex = c(mat), pch = 20) #define the subset of coordinates I'm interested in: shortXY <- expand.grid(1:5, 1:5) #and shuffle these into an erratic sequence: rand.seq <- sample(1:25) shortXY <- shortXY[rand.seq,] #Identify which coordinates in the full dataset are needed (not doubt better ways exist!): needed <- which(paste(xy100[,1],xy100[,2], sep = " ") %in% p...