read.transactions {arules}R Documentation

Read Transaction Data

Description

Reads a transaction data file from disk and creates a transactions object.

Usage

read.transactions(file, format = c("basket", "single"), sep = NULL,
                  cols = NULL, rm.duplicates = FALSE)

Arguments

file the file name.
format a character string indicating the format of the data set. One of "basket" or "single", can be abbreviated.
sep a character string specifying how fields are separated in the data file, or NULL (default). For basket format, this can be a regular expression; otherwise, a single character must be given. The default corresponds to white space separators.
cols For the ‘single’ format, cols is a numeric vector of length two giving the numbers of the columns (fields) with the transaction and item ids, respectively. For the ‘basket’ format, cols can be a numeric scalar giving the number of the column (field) with the transaction ids. If cols = NULL
rm.duplicates a logical value specifying if duplicate items should be removde from the transactions.

Details

For ‘basket’ format, each line in the transaction data file represents a transaction where the items (item labels) are separated by the characters specified by sep. For ‘single’ format, each line corresponds to a single item, containing at least ids for the transaction and the item.

Value

Returns an object of class transactions.

See Also

transactions-class

Examples

## create a demo file using basket format for the example
data <- paste("item1,item2","item1","item2,item3", sep="\n")
cat(data)
write(data, file = "demo_basket")

## read demo data
tr <- read.transactions("demo_basket", format = "basket", sep=",")
inspect(tr)

## create a demo file using single format for the example
## column 1 contains the transaction ID and column 2 contains one item
data <- paste("trans1 item1", "trans2 item1","trans2 item2", sep ="\n")
cat(data)
write(data, file = "demo_single")

## read demo data
tr <- read.transactions("demo_single", format = "single", cols = c(1,2))
inspect(tr)

## tidy up
unlink("demo_basket")
unlink("demo_single")


[Package arules version 1.0-0 Index]