[R] Help on plotting a 3 dimensional surface

[Duncan Murdoch]

On 6/3/2006 5:54 AM, Tor Jørund Sund wrote:
> Hi
> 
>  
> 
> Im working on my master thesis, I need to get a plot currents distributed
> over a surface. 
> 
> I have the data listed in a dataframe with the x coordinates, y coordinates
> and the value.
> 
> Im using the persp function but I’ve not found out how to put the data into
> the z1 variable
> 
>  
> 
> es <-read.table("RDatalog_pass_dev_1_wafers_1_8V.txt",header=T,sep="\t")
> 
> x1 <- seq(0,40, length=40)
> 
> y1 <- x1
> 
> z1 <- ? (es[,5]is the column with the data, es[,3] is the x coocdinate, and
> es[,2] is the y coocrdinate]
> 
> persp(x1,y1,z1)
> 
>  
> 
> I will appreciate all help because this will be a nice thing to present in
> my report.

In order to plot a surface, the z values need to be arranged in a 
matrix, with the x and y values labelling rows and columns.  If you have 
a single z value for each (x,y) pair, you can do a 3d scatterplot using 
the scatterplot3d package, or the cloud function in the lattice package. 
  You can also convert them to a surface using interp from the akima 
package, and then they'll work with persp.

Duncan Murdoch