x2 <- c(-10:20) y2 <- x2*x2/4 + 5*x2 + 3 x1 <- c(-15:25) y1 <- x1*x1*x1/22 - x1*x1*1.505 + 11*x1 - 10 x11() plot(x2, y2, col=2) z <- locator(1) # wait for mouse click or enter pressed # Add a few new plots # Note: doesn't resize the plot area! points(x1, y1, col=3) z <- locator(1) # wait for mouse click or enter pressed plot(1:100, 1:100, type='n') # type='n' : invisible points (1:10*3 + 20, 1:10*3 + 30, pch=letters[1:10]) z <- locator(1)