times-methods: Compute Time Statistics of Sequences

In arulesSequences: Mining Frequent Sequences

Description

Computes the gaps, the minimum or maximum gap, or the span of sequences.

Usage

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

Arguments

x	an object.
type	a string value specifying the type of statistic.

Value

If type = "items" returns a list of vectors of events times corresponding with the elements of a sequence.

If type = "gaps" returns a list of vectors of time differences between consecutive elements of a sequence.

Otherwise, a vector corresponding with the elements of x.

Note

Gap statistics are not defined for sequences of size one, i.e. which contain a single element. NA is used for undefined values.

FIXME lists are silently reduced to vector if possible.

Author(s)

Christian Buchta

See Also

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

Examples

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

##
times(z)
times(z, "gaps")

## all defined
times(z, "span")

## crosstab
table(size = size(z), span = times(z, "span"))

Example output

Loading required package: arules
Loading required package: Matrix

Attaching package: 'arules'

The following objects are masked from 'package:base':

    abbreviate, write


tmdsq-> ## use example data
tmdsq-> data(zaki)

tmdsq-> ## coerce
tmdsq-> z <- as(zaki, "timedsequences")

tmdsq-> z
set of 4 timedsequences 

tmdsq-> ## get time sequences
tmdsq-> summary(timesets(z))
itemMatrix in sparse format with
 4 rows (elements/itemsets/transactions) and
 4 columns (items) and a density of 0.625 

most frequent items:
     10      20      15      25 (Other) 
      3       3       2       2       0 

element (itemset/transaction) length distribution:
sizes
1 2 3 4 
1 1 1 1 

   Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
   1.00    1.75    2.50    2.50    3.25    4.00 

includes extended item information - examples:
  labels eventID
1     10      10
2     15      15
3     20      20

tmdsq-> ## coerce back
tmdsq-> as(z, "transactions")
transactions in sparse format with
 10 transactions (rows) and
 8 items (columns)
[[1]]
[1] 10 15 20 25

[[2]]
[1] 15 20

[[3]]
[1] 10

[[4]]
[1] 10 20 25

[[1]]
[1] 5 5 5

[[2]]
[1] 5

[[3]]
[1] NA

[[4]]
[1] 10  5

[1] 15  5  0 15
    span
size 0 5 15
   1 1 0  0
   2 0 1  0
   3 0 0  1
   4 0 0  1

arulesSequences documentation built on July 2, 2020, 4:09 a.m.