Sorting rules by lift and confidence

2
votes

I am trying to find association rules using the apriori function from arules package in R.

rules <- apriori(data=data, parameter=list(supp=0.001,conf = 0.08), 
                  appearance = list(default="lhs",rhs="YOGHURT"),
                  control = list(verbose=F))

rules <- sort(rules, decreasing=TRUE,by="confidence")

inspect(rules[1:3])


    lhs       rhs      support      confidence       lift
1. {A,B}     {C}       0.04           0.96           0.25
2. {C,A}     {D}       0.05           0.95           0.26
3. {B,D}     {A,C}     0.03           0.93           0.24

With the code showed above I got some association rules saved in the variable "rules" ordered by confidence in a decreasing way. But I would like to order these rules by confidence and by lift at the same time. I tried this but I got an error:

rules <- sort(rules, decreasing=TRUE,by=c("confidence","lift"))

Error in .subset2(x, i, exact = exact) : subscript out of bounds

Is there a way to sort rules by confidence and lift at the same time?

2
rarules
What is rules? What is the desired output? What are you getting instead? Please provide a minimum reproducible example. – nico
Pay attention, the problem is outdated and the new release of ARules library already supports sort(..) now as it's used in the question body. So the answers are actually no longer necessary. – Emadpres

2 Answers

-1
votes

Assuming you got

library(arules)
data("Adult")
rules <- apriori(Adult, parameter = list(supp = 0.5, conf = 0.9, target = "rules"))

then you could try

df <- as(rules, "data.frame") 
df[order(df$lift, df$confidence), ]
3
votes

I have not thought about this. You can copy & paste the following code into your R session after you load arules.

setMethod("sort", signature(x = "associations"),
  function (x, decreasing = TRUE, na.last = NA, by = "support", ...) {
    q <- quality(x)
    q <- q[, pmatch(by, colnames(q)), drop = FALSE]
    if(is.null(q)) stop("Unknown interest measure to sort by.")
    if(length(x) == 0) return(x)

    x[do.call(order, c(q, list(na.last = na.last, decreasing = decreasing)))]
})

Now your original code should work.

> data("Adult")
> rules <- apriori(Adult, parameter = list(supp = 0.5, conf = 0.9, target = "rules"))
> inspect(head(sort(rules, by=c("supp", "conf"))))
  lhs                               rhs                   support confidence      lift
1 {}                             => {capital-loss=None} 0.9532779  0.9532779 1.0000000
2 {}                             => {capital-gain=None} 0.9173867  0.9173867 1.0000000
3 {capital-gain=None}            => {capital-loss=None} 0.8706646  0.9490705 0.9955863
4 {capital-loss=None}            => {capital-gain=None} 0.8706646  0.9133376 0.9955863
5 {native-country=United-States} => {capital-loss=None} 0.8548380  0.9525461 0.9992323
6 {native-country=United-States} => {capital-gain=None} 0.8219565  0.9159062 0.9983862

This will be part of the next release of arules.