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

> ### Name: Plot
> ### Title: Plot One or Two Continuous and/or Categorical Variables
> ### Aliases: Plot ScatterPlot sp BoxPlot bx ViolinPlot vp
> ### Keywords: plot color grouping variable
> 
> ### ** Examples
> 
> # read the data
> d <- rd("Employee", quiet=TRUE)

> d <- Subset(random=.6, quiet=TRUE)  # less computationally intensive
> 
> #---------------------------------------------------
> # traditional scatterplot with two numeric variables
> #---------------------------------------------------
> 
> # scatterplot with all defaults
> Plot(Years, Salary)
dev.new(): using pdf(file="Rplots134.pdf")

>>> Pearson's product-moment correlation 
 
Number of paired values with neither missing, n = 22 


Sample Correlation of Years and Salary: r = 0.881 


Hypothesis Test of 0 Correlation:  t = 8.316,  df = 20,  p-value = 0.000 
95% Confidence Interval for Correlation:  0.730 to 0.950 



> # or use abbreviation sp in place of Plot
> # or use full expression ScatterPlot in place of Plot
> 
> # maximum information, minimum input: scatterplot +
> #  means, outliers, ellipse, least-squares lines with and w/o outliers
> Plot(Years, Salary, enhance=TRUE)
[Ellipse with Murdoch and Chow's function ellipse from the ellipse package]
dev.new(): using pdf(file="Rplots135.pdf")

>>> Pearson's product-moment correlation 
 
Number of paired values with neither missing, n = 22 


Sample Correlation of Years and Salary: r = 0.881 


Hypothesis Test of 0 Correlation:  t = 8.316,  df = 20,  p-value = 0.000 
95% Confidence Interval for Correlation:  0.730 to 0.950 



>>> Outlier analysis with Mahalanobis Distance 
 
  MD                  ID 
-----               ----- 
6.76     Correll, Trevon 
6.54       Capelle, Adam 
 
4.95  Korhalkar, Jessica 
4.72       James, Leslie 
2.55      Billing, Susan 
...                 ... 

> 
> # extend x and y axes
> Plot(Years, Salary, scale_x=c(-10, 35, 10), scale_y=c(0,200000,10))
dev.new(): using pdf(file="Rplots136.pdf")

>>> Pearson's product-moment correlation 
 
Number of paired values with neither missing, n = 22 


Sample Correlation of Years and Salary: r = 0.881 


Hypothesis Test of 0 Correlation:  t = 8.316,  df = 20,  p-value = 0.000 
95% Confidence Interval for Correlation:  0.730 to 0.950 



> 
> Plot(Years, Salary, add="Hi", x1=c(12, 16, 18), y1=c(80000, 100000, 60000))
dev.new(): using pdf(file="Rplots137.pdf")

>>> Pearson's product-moment correlation 
 
Number of paired values with neither missing, n = 22 


Sample Correlation of Years and Salary: r = 0.881 


Hypothesis Test of 0 Correlation:  t = 8.316,  df = 20,  p-value = 0.000 
95% Confidence Interval for Correlation:  0.730 to 0.950 



> 
> 
> 
> #------------------------------------------------------
> # scatterplot matrix from a vector of numeric variables
> #------------------------------------------------------
> 
> # with least squares fit line
> Plot(c(Salary, Years, Pre), fit="lm")
dev.new(): using pdf(file="Rplots138.pdf")
> 
> 
> #--------------------------------------------------------------
> # Trellis graphics and by for groups with two numeric variables
> #--------------------------------------------------------------
> 
> # Trellis plot with condition on 1-variable
> # optionally re-order default alphabetical R ordering by converting
> #   to a factor with lessR factors (which also does multiple variables
> d$Gender <- factors(Gender, levels=c("M", "F"))
> Plot(Years, Salary, by1=Gender)
Error in xtfrm.default(x) : cannot xtfrm 'x'
Calls: Plot ... lapply -> FUN -> as.vector -> xtfrm -> xtfrm.default
Execution halted