Unexpected behaviour by inspect function in R

Question

Working on apriory algorithms and trying to convert rules object to dataframe as below. it works well and data has been stored in datafarme

ruledf=inspect(sort(rules, by = 'lift')[1:100])

But when I changed code to store more observation (1000) in dataframe,then it failed.

ruledf=inspect(sort(rules, by = 'lift')[1:1000])
summary(ruledf)
Length  Class   Mode 
 0   NULL   NULL 

I will really appreciate any help.

Answer 1

the inspect method is only for displaying rules. It does not return any information (see ? inspect). You most likely want to do this

as(rules, "data.frame")

or

DATAFRAME(rules)