search for: xyzsel

Displaying 1 result from an estimated 1 matches for "xyzsel".

2012 Oct 30
1
mapply instead for loop
...<- 1:10 xyz <- data.frame(expand.grid(x,y)[1], expand.grid(x,y)[2], z = rnorm(100)) names(xyz) <- c("x", "y", "z") head(xyz) size <- 2 output <- NULL   ### for loop   for(i in 1:dim(xyz)[1]){ x0 <- xyz[i, "x"] y0 <- xyz[i, "y"] xyzSel <- xyz[xyz$x >= (x0 - size) & xyz$x < (x0 + size) & xyz$y >= (y0 - size) & xyz$y < (y0 + size), ] output[i] <- min(xyzSel$z) } output [[alternative HTML version deleted]]