seqtransn: Number of transitions in a sequence

Description

Computes the number of transitions in each sequence of a sequence object.

Usage

seqtransn(seqdata, with.missing=FALSE, norm=FALSE)

Arguments

seqdata

a state sequence object as defined by the seqdef function.

with.missing

if set to TRUE, missing states (gaps in sequences) are considered as an additional state and included in the DSS sequence. See seqdss.

norm

if set to TRUE, the number of transitions is divided by its theoretical maximum, the length of the sequence minus 1.

Value

a state sequence object containing the number of transitions of each sequence in the object given as argument.

Details

A transition in a sequence is a state change between time/position $t$ and $t+1$. For example, the sequence "A-A-A-A-B-B-A-D-D-D" contains 3 transitions. The maximum number of transitions a sequence can contain is $\ell-1$ where $\ell$ is the length of the sequence. The number of transitions is obtained by subtracting 1 to the length of the the Distinct Successive State (DSS) sequence.

Examples

Run this code

## Creating a sequence object from columns 13 to 24
## in the 'actcal' example data set
data(actcal)
actcal.seq <- seqdef(actcal,13:24)

## Computing the number of transitions
actcal.trans <- seqtransn(actcal.seq)

## Displaying the DSS for the first 10 sequences
actcal.trans[1:10]

## Example with with.missing argument
data(ex1)
ex1.seq <- seqdef(ex1, 1:13)

seqtransn(ex1.seq)
seqtransn(ex1.seq, with.missing=TRUE)