Message-ID: <3EDA2FA3.8020207@statistik.uni-dortmund.de>
Date: 2003-06-01T16:53:55Z
From: Uwe Ligges
Subject: persp & colors
In-Reply-To: <20030601163917.GA19993@pcf004.jinr.ru>
Timur Elzhov wrote:
> Dear R experts!
>
> I use image() & persp() functions for color plotting z(x,y)-type
> graphics. In image() colors correspond to z-values, that's what
> I want. OTOH, in persp() the col option means:
>
> col: the color(s) of the surface facets. Transparent colours are
> ignored. This is recycled to the (nx-1)(ny-1) facets.
>
> but I'd like to persp()' colors behave like in image() function!
>
> Could you help me to solve this problem?
> Thank you very much.
>
>
> --
> WBR,
> Timur.
That's not easy, because you have to redefine x, y and z values.
Simple example:
x <- y <- 1:2
z <- matrix(1:4, 2)
image(x, y, z) # OK, quite nice
but
persp(x, y, z)
has only one facet. So the only way is to calculate the 9 values for x,
y, and z to get the corners for the 4 facets in it.
That's easy for x and y, but can be impossible for z...
Uwe Ligges