Association Rules for Market Basket Analysis (R) cited & modified from: http://www.informit.com/promotions/code-files-modeling-techniques-in-predictive-analytics-141177

library(arules)  # association rules
library(arulesViz)  # data visualization of association rules
library(RColorBrewer)  # color palettes for plots

data(Groceries)  # grocery transactions object from arules package
dim(Groceries)   # 9835 baskets x 169 items  
## [1] 9835  169
inspect(Groceries[1:5])
##     items                     
## [1] {citrus fruit,            
##      semi-finished bread,     
##      margarine,               
##      ready soups}             
## [2] {tropical fruit,          
##      yogurt,                  
##      coffee}                  
## [3] {whole milk}              
## [4] {pip fruit,               
##      yogurt,                  
##      cream cheese ,           
##      meat spreads}            
## [5] {other vegetables,        
##      whole milk,              
##      condensed milk,          
##      long life bakery product}
# as(Groceries, "data.frame")


Examine frequency for each item with support greater than 0.025

par(cex=0.8)
itemFrequencyPlot(Groceries, support = 0.025, xlim = c(0,0.3),
  type = "relative", horiz = TRUE, col = "dark red", las = 1,
  xlab = paste0(
    "Proportion of Market Baskets Containing Item\n",
    "(Item Relative Frequency or Support)"))