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Strange "Peacock like" Images drawn by R
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Basic Program
 `````` x <- seq(-3, 3, length=1000) y <- x f <- function(x, y){ x^2 + y^2 } z <- outer(x, y, f) image(z) `````` click to enlarge (new window)
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Here, if you replace last line by "iamge(z, col=z)", you'll get a strange image!
 `````` x <- seq(-3, 3, length=1000) y <- x f <- function(x, y){ x^2 + y^2 } z <- outer(x, y, f) image(z, col=z) `````` click to enlarge (new window)
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Next figures show images when last line was replaced by "image(z, col=t*z)"
and t is increased from 0.1 to 0.9 by 0.1.
 image(z, 0.1*z)click to enlarge image(z, 0.2*z)click to enlarge image(z, 0.3*z)click to enlarge image(z, 0.4*z)click to enlarge image(z, 0.5*z)click to enlarge image(z, 0.6*z)click to enlarge image(z, 0.7*z)click to enlarge image(z, 0.8*z)click to enlarge image(z, 0.9*z)click to enlarge
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When "f" is replaced by "x*y", another image appears.
 `````` x <- seq(-3, 3, length=1000) y <- x f <- function(x, y){ x*y } z <- outer(x, y, f) image(z, col=abs(z)) `````` click to enlarge
 image(z, 0.5*abs(z))click to enlarge image(z, 3*abs(z))click to enlarge image(z, 10*abs(z))click to enlarge
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Next let's replace "f" by "x^2 - y^2".
 `````` x <- seq(-3, 3, length=1000) y <- x f <- function(x, y){ x^2 - y^2 } z <- outer(x, y, f) image(z, col=abs(z)) `````` click to enlarge
 image(z, 0.2*abs(z))click to enlarge image(z, 0.3*abs(z))click to enlarge image(z, 0.4*abs(z))click to enlarge
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The case in which "f" is "x^2+(y-abs(x)^(2/3))^2".
 `````` x <- seq(-3, 3, length=1000) y <- x f <- function(x, y){ x^2+(y-abs(x)^(2/3))^2 } z <- outer(x, y, f) image(z, col=0.5*z) `````` click to enlarge
 image(z, 0.1*z)click to enlarge image(z, 0.2*z)click to enlarge image(z, 0.3*z)click to enlarge
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