calculating entropy in a sequence of letters

Question

I am trying to calculate shannon's entropy of sequence of letters, for example,

A <- c('A-A-A-A', 'A-B-C-D-E-E', 'A-B-D-F-G-E')

I am trying to use the TraMineR ways to do so, but as I already have a sequene object I am unable to do so using the traMineR package, see below:

http://traminer.unige.ch/doc/seqient.html

Any suggestions? Thanks

Answer 1

Perhaps:

library(TraMineR)
A<- c( 'A-A-A-A', 'A-B-C-D-E-E', 'A-B-D-F-G-E')
B <- as.data.frame(A)
actcal.seq <- seqdef(B)
## Summarize and plot histogram
## of within sequence entropy
actcal.ient <- seqient(actcal.seq)
summary(actcal.ient)
hist(actcal.seq)

UPDATE: Per OP's request, adding Entropy to original data:

 cbind(B, actcal.ient)
#              A   Entropy
#[1]     A-A-A-A 0.0000000
#[2] A-B-C-D-E-E 0.8020465
#[3] A-B-D-F-G-E 0.9207822