EVOLUTION-MANAGER

Edit File: persp.R

### Demos for persp() plots -- things not in example(persp) ### ------------------------- require(datasets) require(grDevices); require(graphics) ## (1) The Obligatory Mathematical surface. ## Rotated sinc function. x <- seq(-10, 10, length.out = 50) y <- x rotsinc <- function(x,y) { sinc <- function(x) { y <- sin(x)/x ; y[is.na(y)] <- 1; y } 10 * sinc( sqrt(x^2+y^2) ) } sinc.exp <- expression(z == Sinc(sqrt(x^2 + y^2))) z <- outer(x, y, rotsinc) oldpar <- par(bg = "white") persp(x, y, z, theta = 30, phi = 30, expand = 0.5, col = "lightblue") title(sub=".")## work around persp+plotmath bug title(main = sinc.exp) persp(x, y, z, theta = 30, phi = 30, expand = 0.5, col = "lightblue", ltheta = 120, shade = 0.75, ticktype = "detailed", xlab = "X", ylab = "Y", zlab = "Z") title(sub=".")## work around persp+plotmath bug title(main = sinc.exp) ## (2) Visualizing a simple DEM model z <- 2 * volcano # Exaggerate the relief x <- 10 * (1:nrow(z)) # 10 meter spacing (S to N) y <- 10 * (1:ncol(z)) # 10 meter spacing (E to W) persp(x, y, z, theta = 120, phi = 15, scale = FALSE, axes = FALSE) ## (3) Now something more complex ## We border the surface, to make it more "slice like" ## and color the top and sides of the surface differently. z0 <- min(z) - 20 z <- rbind(z0, cbind(z0, z, z0), z0) x <- c(min(x) - 1e-10, x, max(x) + 1e-10) y <- c(min(y) - 1e-10, y, max(y) + 1e-10) fill <- matrix("green3", nrow = nrow(z)-1, ncol = ncol(z)-1) fill[ , i2 <- c(1,ncol(fill))] <- "gray" fill[i1 <- c(1,nrow(fill)) , ] <- "gray" par(bg = "lightblue") persp(x, y, z, theta = 120, phi = 15, col = fill, scale = FALSE, axes = FALSE) title(main = "Maunga Whau\nOne of 50 Volcanoes in the Auckland Region.", font.main = 4) par(bg = "slategray") persp(x, y, z, theta = 135, phi = 30, col = fill, scale = FALSE, ltheta = -120, lphi = 15, shade = 0.65, axes = FALSE) ## Don't draw the grid lines : border = NA persp(x, y, z, theta = 135, phi = 30, col = "green3", scale = FALSE, ltheta = -120, shade = 0.75, border = NA, box = FALSE) ## `color gradient in the soil' : fcol <- fill ; fcol[] <- terrain.colors(nrow(fcol)) persp(x, y, z, theta = 135, phi = 30, col = fcol, scale = FALSE, ltheta = -120, shade = 0.3, border = NA, box = FALSE) ## `image like' colors on top : fcol <- fill zi <- volcano[ -1,-1] + volcano[ -1,-61] + volcano[-87,-1] + volcano[-87,-61] ## / 4 fcol[-i1,-i2] <- terrain.colors(20)[cut(zi, stats::quantile(zi, seq(0,1, length.out = 21)), include.lowest = TRUE)] persp(x, y, 2*z, theta = 110, phi = 40, col = fcol, scale = FALSE, ltheta = -120, shade = 0.4, border = NA, box = FALSE) ## reset par(): par(oldpar)