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

> ### Name: trapezoid
> ### Title: The Trapezoidal Distribution
> ### Aliases: Trapezoid trapezoid dtrapezoid ptrapezoid qtrapezoid
> ###   rtrapezoid
> ### Keywords: distribution
> 
> ### ** Examples
> 
> 	## Plot default trapezoid distribution
> 	curve(dtrapezoid(x, min = 0, mode1 = 1/3, mode2 = 2/3, max = 1, 
+ 	  n1 = 2, n3 = 2, alpha = 1), from = 0, to = 1)
> 	
> 	
> 	## Plot triangular trapezoid distribution
> 	curve(dtrapezoid(x, min = 0, mode1 = 1/2, mode2 = 1/2, max = 1, 
+ 	  n1 = 2, n3 = 2, alpha = 1), from = 0, to = 1)
> 	
> 	
> 	## Explore effects of n1, n3, and alpha parameters
> 	# plyr and ggplot2 are required for this example
> 	require(plyr)
Loading required package: plyr
Warning in library(package, lib.loc = lib.loc, character.only = TRUE, logical.return = TRUE,  :
  there is no package called 'plyr'
> 	require(ggplot2)
Loading required package: ggplot2
Warning in library(package, lib.loc = lib.loc, character.only = TRUE, logical.return = TRUE,  :
  there is no package called 'ggplot2'
> 	
> 	x <- seq(from = 0, to = 1, by = 0.01)	
> 	
> 	# Create a list of arguments, varying n1, n3, and alpha
> 	arguments <- list()
> 	arguments[['A']] <- list(x = x, n1 = 2, n3 = 2, alpha = 0.8)
> 	arguments[['B']] <- list(x = x, n1 = 1.5, n3 = 1.5, alpha = 1)
> 	arguments[['C']] <- list(x = x, n1 = 2.5, n3 = 2.5, alpha = 1.5)
> 	arguments[['D']] <- list(x = x, n1 = 1.5, n3 = 2.5, alpha = 0.5)
> 	arguments[['E']] <- list(x = x, n1 = 2.5, n3 = 1.5, alpha = 1)
> 	arguments[['F']] <- list(x = x, n1 = 0.5, n3 = 0.5, alpha = 1.5)
> 	arguments[['G']] <- list(x = x, n1 = 1.5, n3 = 0.5, alpha = 0.5)
> 	arguments[['H']] <- list(x = x, n1 = 2.5, n3 = 0.5, alpha = 1)
> 	arguments[['I']] <- list(x = x, n1 = 0.5, n3 = 1.5, alpha = 1.5)
> 	arguments[['J']] <- list(x = x, n1 = 0.5, n3 = 2.5, alpha = 0.5)
> 	
> 	# Calculate the distributions
> 	plot.data <- ldply(arguments, function(z)
+ 	{
+ 	  x <- z$x
+ 	  density <- dtrapezoid(x = z$x, min = 0, mode1 = 0.2, mode2 = 0.8,
+ 	    max = 1, n1 = z$n1, n3 = z$n3, alpha = z$alpha)
+ 	  args <- paste("n1 = ", z$n1, ", n3 = ", z$n3, ", alpha = ", z$alpha, 
+ 	    sep="", collapse="")
+ 	  out <- data.frame(x, density, args)
+ 	})
Error in ldply(arguments, function(z) { : could not find function "ldply"
Execution halted