timeFrequency-methods {arulesSequences}

Count Event Times

Description

timeFrequency counts the number of occurrences of event times, of the time gaps between the events of a sequence, the minimum or maximum gap of a sequence, or the span of a sequence.

timeTable cross-tabulates the above statistics for items or itemsets. For items the sequences are reduced to the events containing the item.

firstOrder computes a first order model, i.e. a table of counts of state changes among a collection of timed sequences, where the elements or the times can be the states.

Usage

## S4 method for signature 'timedsequences'
timeFrequency(x, type = c("times", "gaps", "mingap", "maxgap",
                          "span"))

## S4 method for signature 'timedsequences'
timeTable(x, type = c("times","gaps", "mingap", "maxgap", "span"),
	  itemsets = FALSE)

## S4 method for signature 'timedsequences'
firstOrder(x, times = FALSE)

Arguments

x

an object.

type, itemsets, times

a string (logical) value specifying the type of count.

Value

For timeFrequency returns a vector of counts corresponding with the set of distinct event times, the set of gaps or spans as indicated by the names attribute.

For timeTable returns a table of counts with the rownames corresponding with the reference set of distinct items or itemsets.

For firstOrder a matrix of counts corresponding with the set of distinct itemsets or event times.

Note

Undefined values are not included in the counts, e.g. the mingap of a sequence with one element only. Thus, except for times and gaps the counts (per item or itemset) always add up to less than or equal the number of sequences, i.e. length(x).

Author(s)

Christian Buchta

See Also

Class sequences, timedsequences, method size, times, itemFrequency.

Examples

## continue example
example("timedsequences-class")

## totals
timeFrequency(z)
timeFrequency(z, "gaps")
timeFrequency(z, "span")

## default items
timeTable(z)
timeTable(z, "gaps")
timeTable(z, "span")

## beware of large data sets
timeTable(z, itemsets = TRUE)


## first order models
firstOrder(z)
firstOrder(z, times = TRUE)