Linking group results to sequence data after cluster analysis: sqclusterdat

[Anita Minh]

I’m trying to do optimal matching and cluster analysis for sequences of a variable with 3 states and 4 time points, formatted as follows:

IDvar Seqvar Time
1 2 1
1 2 2
1 0 3
1 0 4
2 1 1
2 0 2
2 0 3
2 0 4

Using the sq package, I was able to identify 81 unique sequences. I then performed optimal matching on the full data set, and hierarchical cluster analysis using Ward's method with the following commands:
sqset Seqvar IDvar time
sqclusterdat
clustermat wardslinkage SQdist, name(wards) add
cluster generate clustervar = groups(2/10), ties(more) name(wards)

At this point, I am able to see how my cluster variables are distributed using the command tab1 clustervar*. However, when I attempt to link the clustered data with sequence data, by running

sqclusterdat, return keep(clustervar*)

I am met with the following message:

Group results could not be merged to sequence data.
Returned to original data

What am I missing?

Thanks!