[R] persp question

[Duncan Murdoch]

On 11/03/2008 2:40 PM, markleeds at verizon.net wrote:
> someone sent in a question earlier about doing
> something in 3D so i took a stab at it purely
> for educational purposes ( i'm not even sure that I understood the question actually ).  
> 
> Unfortunately, persp gives me an error that I don't understand because it says "object y not found". I'm sending y in as a parameter to persp similar to what ?persp shows in one of oits examples so I must not be understanding something. the code is below. thanks.
> 
> DF <- read.table(textConnection("station month bas
> 190 5 0.00
> 190 7 1.563
> 190 10 0.000
> 190 11 0.000
> 202 4  18.750
> 202 5 18.750
> 202 7 6.250
> 202 10 4.80
> 202 11 3.125
> 198 4 18.750
> 198 10 3.20
> 198 11 12.500
> 205 4 0.000
> 205 5 0.000
> 205 10 0.000
> 205 11 0.00"),header=TRUE,stringsAsFactors=FALSE)
> 
> #print(DF)
> #print(str(DF))
> 
> temp1 <- seq(1,max(DF$month),length.out=max(DF$month))
> temp2 <- seq(min(DF$station),max(DF$station),by=1)
> print(temp1)
> print(temp2)
> 
> persp(x = seq(1,max(DF$month),length.out=max(DF$month)),
>         y = seq(min(DF$station),max(DF$station),by=1),
>         z = DF$bas,
>         xlim=range(x), ylim=range(y), zlim=range(z))

The values you pass to persp() are expressions to be evaluated in your 
workspace. Since you don't have variables x, y or z defined, you can't 
specify range(x), range(y) or range(z) as arguments.  (Things are 
different for the defaults for the parameters:  those are evaluated in 
the local frame set up for the call.)

Duncan Murdoch