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 0.6-3 Index]