[R] how to rotate a triangle image(ZMAT) ?
François Pinard
pinard at iro.umontreal.ca
Tue Jun 27 21:45:33 CEST 2006
[Cleber N.Borges]
> how to align this Zmat (triangle image) in X axis? I would like that
> the triangle's base become in the X axis and the triangle's height
> become in the Y axis. Is there some trick for make this?
I'm not fully sure of what is the base and the height of the triangle,
but if I guess correctly, you may peek at "?image", the last paragraph
of the "Details:" section, and also in the "Examples:" section, where it
says "Need to transpose and flip matrix horizontally.". Maybe you'll
find some explanations or ideas in there.
> f <- function(x, y) {
> z = 1-x-y
> z[z < (-1e-15)] <- NA
return(-100*x+0*y+100*z)
> }
> x = seq(1, 0, by = -0.01)
> y = seq(1, 0, by = -0.01)
> zmat = outer(x, y, f)
> image(zmat, col=terrain.colors(10))
> contour(zmat, add=T)
Another idea is to exchange "x, y" in the "outer" call, and maybe also
use "rev()" on one of them.
--
François Pinard http://pinard.progiciels-bpi.ca
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