Read Transaction Data
Reads a transaction data file from disk and creates a
transactions object.
read.transactions(file, format = c("basket", "single"),
header = FALSE, sep = "",
cols = NULL, rm.duplicates = FALSE,
quote = "\"'", skip = 0,
encoding = "unknown")file |
the file name or connection. |
format |
a character string indicating the format of the data
set. One of |
header |
a logical value indicating whether the file contains the names of the variables as its first line. |
sep |
a character string specifying how fields are separated in
the data file. The default ( |
cols |
For the ‘single’ format, |
rm.duplicates |
a logical value specifying if duplicate items should be removed from the transactions. |
quote |
a list of characters used as quotes when reading. |
skip |
number of lines to skip in the file before start reading data. |
encoding |
character string indicating the encoding which is passed to
|
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.
Returns an object of class
transactions.
Michael Hahsler and Kurt Hornik
## create a demo file using basket format for the example
data <- paste(
"# this is some test data",
"item1, item2",
"item1",
"item2, item3",
sep="\n")
cat(data)
write(data, file = "demo_basket.txt")
## read demo data (skip the comment in the first line)
tr <- read.transactions("demo_basket.txt", format = "basket", sep=",", skip = 1)
inspect(tr)
## make always sure that the items were properly separated
itemLabels(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.txt")
## read demo data
tr <- read.transactions("demo_single.txt", format = "single", cols = c(1,2))
inspect(tr)
## create a demo file using single format with column headers
data <- paste(
"item_id;trans_id",
"item1;trans1",
"item1;trans2",
"item2;trans2",
sep ="\n")
cat(data)
write(data, file = "demo_single.txt")
## read demo data
tr <- read.transactions("demo_single.txt", format = "single",
header = TRUE, sep = ";", cols = c("trans_id","item_id"))
inspect(tr)
## tidy up
unlink("demo_basket.txt")
unlink("demo_single.txt")Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.