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 pl ScatterPlot sp BoxPlot bx ViolinPlot vp
> ### Keywords: plot color grouping variable
> 
> ### ** Examples
> 
> # read the data
> d <- rd("Employee", in.lessR=TRUE, 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="Rplots138.pdf")

>>> Pearson's product-moment correlation 
 
Number of paired values with neither missing, n = 21 


Sample Correlation of Years and Salary: r = 0.861 


Alternative Hypothesis: True correlation is not equal to 0 
  t-value: 7.366,  df: 19,  p-value: 0.000 
 
95% Confidence Interval of Population Correlation 
  Lower Bound: 0.682      Upper Bound: 0.942 



> # 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="Rplots139.pdf")

>>> Pearson's product-moment correlation 
 
Number of paired values with neither missing, n = 21 


Sample Correlation of Years and Salary: r = 0.861 


Alternative Hypothesis: True correlation is not equal to 0 
  t-value: 7.366,  df: 19,  p-value: 0.000 
 
95% Confidence Interval of Population Correlation 
  Lower Bound: 0.682      Upper Bound: 0.942 



>>> Outlier analysis with Mahalanobis Distance 
 
  MD                  ID 
-----               ----- 
6.30       Capelle, Adam 
6.20     Correll, Trevon 
 
4.63  Korhalkar, Jessica 
4.19       James, Leslie 
2.55 Cassinelli, Anastis 
...                 ... 

> 
> 
> 
> #------------------------------------------------------
> # 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="Rplots140.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 sort.list(y) : 'x' must be atomic for 'sort.list'
Have you called 'sort' on a list?
Calls: Plot -> factor -> sort.list
Execution halted