R Under development (unstable) (2024-03-19 r86153 ucrt) -- "Unsuffered Consequences"
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> 
> library(lattice)
> 
> pdf("wireframe.pdf")
> 
> data(volcano)
> 
> foo <-
+     data.frame(z = as.vector(volcano),
+                x = rep(1:87, 61),
+                y = rep(1:61, each = 87))
> 
> wireframe(z ~ x * y, foo)
> 
> ## this used to give an error, but seems fine now (?)
> wireframe(z ~ x * y, foo, subset = z > 150)
> 
> 
> ## Example 1 (a). valgrind shows warnings, starting with
> 
> 
> ## ==9058== Invalid read of size 8
> ## ==9058==    at 0xA450AFF: wireframePanelCalculations (threeDplot.c:291)
> 
> ## and subsequently in various other places in that function leading to
> 
> ## ==9058== Conditional jump or move depends on uninitialised value(s)
> ## ==9058==    at 0x3FFAA466CF: __printf_fp (in /lib64/libc-2.4.so)
> ## ==9058==    by 0x3FFAA423AE: vfprintf (in /lib64/libc-2.4.so)
> ## ==9058==    by 0x3FFAA4A477: fprintf (in /lib64/libc-2.4.so)
> ## ==9058==    by 0x94975BE: PostScriptRLineTo (devPS.c:2683)
> 
> ## A bit more tracing shows it is accessing element 4016 in an array of
> ## length 2456, and the plot seems nonsense (and random) when viewed on
> ## screen. (BDR, 2006/09/17)
> 
> ## DS's earlier comment: what's this supposed to do ?  weird thing is,
> ## result is random (probably indicator of memory access errors)
> 
> if (FALSE)
+ {
+ 
+     wireframe(z + I(z + 100) ~ x * y, foo,
+               subset = z > 150,
+               scales = list(arrows = FALSE))
+ }
> 
> ## this works as expected
> 
> wireframe(z + I(z + 100) ~ x * y, foo)
> 
> ## Example 1 (b).  Another way of seeing the problem:
> 
> ## this is OK:
> 
> bar <- foo
> bar$z[bar$z < 150] <- NA
> wireframe(z + I(z + 100) ~ x * y, bar,
+           scales = list(arrows = FALSE))
> 
> ## but this is not
> if (FALSE)
+ {
+     wireframe(z + I(z + 100) ~ x * y,
+               subset(bar, !is.na(z)),
+               scales = list(arrows = FALSE))
+ }
> 
> 
> ## Example 2.  Probably another example of the same "bug": see
> ## https://stat.ethz.ch/pipermail/r-devel/2005-September/034544.html
> 
> 
> n <- 20
> psteps <- 50
> binomtable <- function(n, psteps)
+ {
+     x <- (0:(10*n))/10
+     p <- (0:psteps)/psteps
+     dd <- expand.grid(x=x,p=p)
+     dd$F <- pbinom(dd$x,n,dd$p)
+     dd$x0 <-trunc(dd$x)
+     dd
+ }
> 
> bt <- binomtable(n = 5, psteps = 100)
> bt[bt$x - bt$x0 >= 0.9, ]$F <- NA
> 
> if (FALSE)
+ {
+     ## this is problematic
+     wireframe(F ~ x * p, bt,
+               groups = bt$x0, shade = TRUE,
+               scales = list(arrows = FALSE)) 
+ }
> 
> ## this one OK
> wireframe(F ~ x * p, bt, shade = TRUE,
+           scales = list(arrows = FALSE))
> 
> ## this too
> wireframe(F ~ x * p | factor(x0), bt,
+           ## groups = bt$x0,
+           shade = TRUE,
+           scales = list(arrows = FALSE)) 
> 
> 
> ## Working hypothesis: the problem crops up when there are groups
> ## (specified either directly or through the formula interface) AND x
> ## and y values for each group don't represent the full evaluation
> ## grid.  The second condition is a bit unclear.  In example 2, each
> ## group's support is disjoint from that of the others.  In example 1,
> ## both groups have the same support, they are just not the full grid.
> 
> dev.off()
null device 
          1 
> 
> proc.time()
   user  system elapsed 
   3.60    0.20    3.79