Summarizing attributes across sequences in a single sequence object?

Question

I'm using TraMineR to analyze sets of sequences. Each coherent set of sequences may contain 100 work processes from a single project for a single period of time. Using TraMineR I can easily calculate descriptive statistics for each sequence, however I'm more interested in descriptive statistics of the sequence object itself - subsuming all the smaller sequences within.

For example, to get state frequencies, I run:

seqstatd(sequences.sts)

However, this gives me the state frequencies for each sequence within my sequence object. I want to access the frequencies of states across all sequences inside of my sequence object. How can I accomplish this?

Answer 1

I am not sure to understand your question since seqstatd() returns the cross-sectional frequencies at each successive position, and NOT the state frequencies for each sequence. The latter is returned by seqistatd().

Assuming you refer to the outcome of seqistatd() you would get the mean time spent in each state with seqmeant(sequence.sts).

For other summaries you can use the apply function. For instance, you get the variance of the time spent in each state with

tab <- seqistatd(mvad.seq)
vart <- apply(tab,2,var)
head(vart)

Hope this helps.