tidLists-class | R Documentation |
Class to represent transaction ID lists and associated methods.
tidLists(x)
## S4 method for signature 'tidLists'
summary(object, maxsum = 6, ...)
## S4 method for signature 'tidLists'
dim(x)
## S4 method for signature 'tidLists'
dimnames(x)
## S4 replacement method for signature 'tidLists,list'
dimnames(x) <- value
## S4 method for signature 'tidLists'
length(x)
## S4 method for signature 'tidLists'
t(x)
## S4 method for signature 'tidLists'
transactionInfo(x)
## S4 replacement method for signature 'tidLists'
transactionInfo(x) <- value
## S4 method for signature 'tidLists'
itemInfo(object)
## S4 replacement method for signature 'tidLists'
itemInfo(object) <- value
## S4 method for signature 'tidLists'
itemLabels(object)
## S4 method for signature 'tidLists'
labels(object)
x , object |
the object |
maxsum |
maximum numbers of itemsets shown in the summary |
... |
further arguments |
value |
replacement value |
Transaction ID lists contains a set of lists. Each list is associated with an item/itemset and stores the IDs of the transactions which support the item/itemset.
tidLists
uses the class
Matrix::ngCMatrix to efficiently store the
transaction ID lists as a sparse matrix. Each column in the matrix
represents one transaction ID list.
tidLists
can be used for different purposes. For some operations
(e.g., support counting) it is efficient to coerce a
transactions database into tidLists
where each
list contains the transaction IDs for an item (and the support is given by
the length of the list).
The implementation of the Eclat mining algorithm (which uses transaction ID list intersection) can also produce transaction ID lists for the found itemsets as part of the returned itemsets object. These lists can then be used for further computation.
summary(tidLists)
: create a summary
dim(tidLists)
: get dimensions. The rows represent the itemsets and the
columns are the transactions.
dimnames(tidLists)
: get dimnames
dimnames(x = tidLists) <- value
: replace dimnames
length(tidLists)
: get the number of itemsets.
t(tidLists)
: this object is not transposable.
t()
results in an error.
transactionInfo(tidLists)
: get the transaction info data.frame
transactionInfo(tidLists) <- value
: replace the the transaction info data.frame
itemInfo(tidLists)
: get the item info data.frame
itemInfo(tidLists) <- value
: replace the item info data.frame
itemLabels(tidLists)
: get the item labels
labels(tidLists)
: convert the tid lists into a text representation.
data
an object of class Matrix::ngCMatrix.
itemInfo
a data.frame
transactionInfo
a data.frame
Objects are created
as part of the
itemsets mined by eclat()
with tidLists = TRUE
in the
ECparameter object.
by supportingTransactions()
.
by coercion from an object of class transactions.
by calls of the form new("tidLists", ...)
.
as("tidLists", "list")
as("list", "tidLists")
as("tidLists", "ngCMatrix")
as("tidLists", "transactions")
as("transactions", "tidLists")
as("tidLists", "itemMatrix")
as("itemMatrix", "tidLists")
Michael Hahsler
Other itemMatrix and transactions functions:
abbreviate()
,
c()
,
crossTable()
,
duplicated()
,
extract
,
hierarchy
,
image()
,
inspect()
,
is.superset()
,
itemFrequency()
,
itemFrequencyPlot()
,
itemMatrix-class
,
match()
,
merge()
,
random.transactions()
,
sample()
,
sets
,
size()
,
supportingTransactions()
,
transactions-class
,
unique()
## Create transaction data set.
data <- list(
c("a","b","c"),
c("a","b"),
c("a","b","d"),
c("b","e"),
c("b","c","e"),
c("a","d","e"),
c("a","c"),
c("a","b","d"),
c("c","e"),
c("a","b","d","e")
)
data <- as(data, "transactions")
data
## convert transactions to transaction ID lists
tl <- as(data, "tidLists")
tl
inspect(tl)
dim(tl)
dimnames(tl)
## inspect visually
image(tl)
## mine itemsets with transaction ID lists
f <- eclat(data, parameter = list(support = 0, tidLists = TRUE))
tl2 <- tidLists(f)
inspect(tl2)
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