TraMineR (version 2.2-10)

seqdss: Extract sequences of distinct successive states

Description

Extract the sequence of distinct successive states from each sequence in a object.

Usage

seqdss(seqdata, with.missing=FALSE)

Value

a sequence object containing the distinct state sequence (DSS) for each sequence in the object given as argument.

Arguments

seqdata

a sequence object as defined by the seqdef function.

with.missing

Should non-void missing values be considered as regular states? See Details.

Author

Alexis Gabadinho and Gilbert Ritschard

Details

Returns a sequence object containing the sequences of distinct successive states (DSS). The spell durations are not taken into account. E.g., the DSS contained in 'D-D-D-D-A-A-A-A-A-A-A-D' is 'D-A-D'. Associated durations can be extracted with the seqdur function.

When {with.missing=TRUE}, non-void missing values are considered as a regular state of the alphabet. For example, the DSS of A-A-*-*-*-B-B-C-C-D is A-*-B-C-D.

When with.missing=FALSE (default) missing values are ignored and a substring A-A-*-*-*A for example will be considered as a single spell in A while the DSS of this substring would be A-*-A whith with.missing=TRUE.

See seqdef on options for handling missing values when creating sequence objects.

See Also

seqdur.

Examples

## Creating a sequence object from columns 13 to 24
## in the 'actcal' example data set
## Here we retain the first 10 sequences only.
data(actcal)
actcal.seq <- seqdef(actcal[1:10,13:24])

## Retrieving the DSS
actcal.dss <- seqdss(actcal.seq)

## Displaying the DSS for the first 10 sequences
actcal.dss

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

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