[R] persp, add lines/highlights

[Robin Hankin]

Hello everyone

I always cut-n-paste Paul's suggestions and end up learning something!

In this case, though, I have a query.

I was wondering how the second persp() call dealt with hidden line
removal,  because pieces of mesh with NA values are see-through.

If you replace xi in the code below with 10:28
and yi with 19:20, then all the pink grid
appears in front of the blue grid; I would expect  the blue grid to 
hide some of the pink
grid.  Is there any way to enforce
hidden line removal here?


rksh


On May 31, 2005, at 01:14 am, Paul Murrell wrote:

> Hi
>
>
> jjorgensen at fastmail.fm wrote:
>> Hello R-sters,
>> I'm trying to add several lines to a response surface that I've 
>> plotted
>> using persp().  I've tried lines() using the "trans3d" function but 
>> I've
>> been unsuccessful in getting it to work (R v2.0.1).  Essentially, I'm
>> trying to highlight one or more of the surface wireframe lines in a
>> bolder (or different) color.  Any tips from those of you who have some
>> experience with this would be greatly appreciated.  [Would it be 
>> easier
>> using wireframe() in library(lattice) instead?]
>
>
> Here's an example that just overlays two persp() plots ...
>
> x <- seq(-10, 10, length= 30)
> y <- x
> f <- function(x,y) { r <- sqrt(x^2+y^2); 10 * sin(r)/r }
> z <- outer(x, y, f)
> z[is.na(z)] <- 1
> op <- par(bg = "white")
> persp(x, y, z, theta = 30, phi = 30, expand = 0.5, col = "lightblue",
>       zlim=range(z))
>
> # overlay plot with just "highlighted" surface area
> par(new=TRUE)
> z2 <- matrix(NA, ncol=30, nrow=30)
> xi <- 15:18
> yi <- 13:14
> z2[xi, yi] <- z[xi, yi]
> persp(x, y, z2, theta = 30, phi = 30, expand = 0.5,
>       zlim=range(z), border="red", col="pink", box=FALSE, axes=FALSE)
>
>
>> And, any suggestions on how to add text outside of the persp() plot 
>> next
>> to the highlighted line would be much appreciated.
>
>
> Do you mean like a legend?
>
> Paul
> -- 
> Dr Paul Murrell
> Department of Statistics
> The University of Auckland
> Private Bag 92019
> Auckland
> New Zealand
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>
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--
Robin Hankin
Uncertainty Analyst
National Oceanography Centre, Southampton
European Way, Southampton SO14 3ZH, UK
  tel  023-8059-7743