# 3D plots:  persp, contour, image

# Planes
x <- y <- seq(-5, 5, length=50)

# For the third dimension, need to use the "outer" function
z <- outer(x, y, "+")
persp(x, y, z )

# For more complicated function, define a function
f2 <- function(x, y){ x * sin(y) + y*sin(x)}
z2 <- outer(x, y, "f2")

persp( x, y, z2)
persp(x, y, z2, theta=45, phi=45, col="slateblue")

# For a list of colours:
colors()
colours()

# Fancier
x <- seq(-10, 10, length= 50)
y <- x
f <- function(x,y) { r <- sqrt(x^2+y^2); 10 * sin(r)/r }
z <- outer(x, y, f)

persp(x, y, z, theta=45, phi=30, col="skyblue")
persp(x, y, z, theta=30, phi=45, col="orange")
persp(x, y, z, theta = 30, phi = 30, col = "lightblue",
   ltheta = 120, shade = 0.75, ticktype = "detailed",
   xlab = "X", ylab = "Y", zlab = "sin(3x) cos(5y)" )


contour(x, y, z)
image(x, y, z)
image(x, y, z, col=rainbow(n=100))
image(x, y, z, col=terrain.colors(n=100))

#