seqstart {TraMineRextras}

Aligning sequence data on a new start time.

Description

Changing the position alignment of a set of sequences.

Usage

seqstart(seqdata, data.start, new.start, tmin = NULL, tmax = NULL, missing = NA)

Arguments

seqdata

a data frame or matrix containing sequence data.

data.start

Integer. The actual starting date of the sequences. In case of sequence-dependent start dates, should be a vector of length equal to the number of rows of seqdata.

new.start

Integer. The new starting date. In case of sequence-dependent start dates, should be a vector of length equal to the number of rows of seqdata.

tmin

Integer. Start position on new position axis. If NULL, it is guessed from the data.

tmax

Integer. End position on new position axis. If NULL, it is guessed from the data.

missing

Character. Code used to fill missing data in the new time axis.

Value

A matrix.

Note

Warning: This function needs further testing.

Author(s)

Matthias Studer

Examples

#An example data set
paneldata <- matrix(c("A" ,"A" , "B" , "B" , "B",
"A" , "A" , "B" , "B" , "B",
"A" , "A",  "B" , "B" , "B" ,
"A"  ,"A" , "A" , "B"  ,"B" ,
"A"  ,"A" , "A" , "A" , "B"), byrow=TRUE, ncol=5)
colnames(paneldata) <- 2000:2004

print(paneldata)

## Assuming data are aligned on calendar years, starting in 2000
## Change from calendar date to age alignment
startyear <- 2000
birthyear <- 1995:1999
agedata <- seqstart(paneldata, data.start=startyear, new.start=birthyear)
colnames(agedata) <- 1:ncol(agedata)
print(agedata)

## Retaining only ages between 3 and 7 (4th and 8th year after birthyear).
seqstart(paneldata, data.start=startyear, new.start=birthyear, tmin=4, tmax=8, missing="*")

## Changing back from age to calendar time alignment
ageatstart <- startyear - birthyear
seqstart(agedata, data.start=1,  new.start=ageatstart)
## Same but dropping right columns filled with NA's
seqstart(agedata, data.start=1,  new.start=ageatstart, tmax=5)