Running examples in 'zenplots-Ex.R' failed
The error most likely occurred in:

> ### Name: zenplot
> ### Title: Main function to create a zenplot
> ### Aliases: zenplot
> ### Keywords: hplot
> 
> ### ** Examples
> 
> ### Basics #####################################################################
> 
> ## Generate some data
> n <- 1000 # sample size
> d <- 20 # dimension
> set.seed(271) # set seed (for reproducibility)
> x <- matrix(rnorm(n * d), ncol = d) # i.i.d. N(0,1) data
> 
> ## A basic zenplot
> res <- zenplot(x)
> stopifnot(identical(res, unfold(nfaces = d - 1)))
> ## => The return value of zenplot() is the underlying unfold()
> 
> ## Some missing data
> z <- x
> z[seq_len(n-10), 5] <- NA # all NA except 10 points
> zenplot(z)
> 
> ## Another column with fully missing data (use arrows)
> ## Note: This could be more 'compactified', but is technically
> ##       more involved
> z[, 6] <- NA # all NA
> zenplot(z)
> 
> ## Lists of vectors, matrices and data frames as arguments (=> groups of data)
> ## Only two vectors
> z <- list(x[,1], x[,2])
> zenplot(z)
> 
> ## A matrix and a vector
> z <- list(x[,1:2], x[,3])
> zenplot(z)
> 
> ## A matrix, NA column and a vector
> z <- list(x[,1:2], NA, x[,3])
> zenplot(z)
> z <- list(x[,1:2], cbind(NA, NA), x[,3])
> zenplot(z)
> z <- list(x[,1:2], 1:10, x[,3])
> zenplot(z)
> 
> ## Without labels or with different labels
> z <- list(A = x[,1:2], B = cbind(NA, NA), C = x[,3])
> zenplot(z, labs = NULL) # without any labels
> zenplot(z, labs = list(group = NULL, group2d = TRUE)) # without group labels
> zenplot(z, labs = list(group = NULL)) # without group labels unless groups change
> zenplot(z, labs = list(var = NULL)) # without variable labels
> zenplot(z, labs = list(var = "Variable ", sep = " - ")) # change default labels
> 
> ## Example with a factor
> zenplot(iris)
> zenplot(iris, lim = "global") # global scaling of axis
> zenplot(iris, lim = "groupwise") # acts as 'global' here (no groups in the data)
> 
> 
> ### More sophisticated examples ################################################
> 
> ## Note: The third component (data.frame) naturally has default labels.
> ##       zenplot() uses these labels and prepends a default group label.
> z <- list(x[,1:5], x[1:10, 6:7], NA,
+           data.frame(x[seq_len(round(n/5)), 8:19]), cbind(NA, NA), x[1:10, 20])
> zenplot(z, labs = list(group = "Group ")) # change the group label (var and sep are defaults)
> ## Alternatively, give z labels
> names(z) <- paste("Group", LETTERS[seq_len(length(z))]) # give group names
> zenplot(z) # uses given group names
> ## Now let's change the variable labels
> z. <- lapply(z, function(z.) {
+                      if(!is.matrix(z.)) z. <- as.matrix(z.)
+                      colnames(z.) <- paste("Var.", seq_len(ncol(z.)))
+                      z.
+                      }
+             )
> zenplot(z.)
> 
> 
> ### A dynamic plot based on 'loon' (if installed and R compiled with tcl support)
> 
> 
> 
> ### Providing your own turns ###################################################
> 
> ## A basic example
> turns <- c("l","d","d","r","r","d","d","r","r","u","u","r","r","u","u","l","l",
+            "u","u","l","l","u","u","l","l","d","d","l","l","d","d","l","l",
+            "d","d","r","r","d","d")
> zenplot(x, plot1d = "layout", plot2d = "layout", turns = turns) # layout of plot regions
> ## => The tiles stick together as ispace = 0.
> zenplot(x, plot1d = "layout", plot2d = "layout", turns = turns,
+         pkg = "grid") # layout of plot regions with grid
> ## => Here the tiles show the small (default) ispace
> 
> ## Another example (with own turns and groups)
> zenplot(list(x[,1:3], x[,4:7]), plot1d = "arrow", plot2d = "rect",
+         turns = c("d", "r", "r", "r", "r", "d",
+                   "d", "l", "l", "l", "l", "l"), last1d = FALSE)
> 
> 
> ### Providing your own plot1d() or plot2d() ####################################
> 
> ## Creating a box
> zenplot(x, plot1d = "label", plot2d = function(zargs)
+     density_2d_graphics(zargs, box = TRUE))
Error in exists(as.character(substitute(plot2d))) : 
  first argument has length > 1
Calls: zenplot -> exists
Execution halted