[R] 4 dimensional graphics

[Alberto Monteiro]

Petr PIKAL wrote:
> 
> I want to display 4 dimensional space by some suitable way.
>
You probably need an LSD monitor :-)

> I searched CRAN and found miscellaneous 3 dim graphics
> packages which I maybe can modify but anyway I am open
> to any hint how to 
> efficiently display data like:
> 
> longitude, latitude, height, value
>
I imagine you want to plot a function with domain R^2
and contradomain R^2?

Check this:
http://en.wikipedia.org/wiki/Image:WeierstrassP.png

It's the graphic of a function that takes complex numbers
and returns complex numbers (and it was done in R); 
the way to plot this was:

f: (x + y i) -> (x' + y' i)

x, y : normal (x,y) coordinates in the plot

x', y': converted to a color code, where the radius
  sqrt(x'^2 + y'^2) became the intensity ('value', in
  the hsv function) and the direction atan2(y',x') 
  became the hue

Probably you could do the same here, converting height and
value to colors?

OTOH, if it's a function from R^3 to R:

  f: (lat, lon, h) -> (value)

then I guess the best way is to replace one dimension to time,
and create animations.

Alberto Monteiro