Ability estimates for partial credit model

Dear all,

I'm working on ability estimates using Rasch model. Using the "ltm" 
package, the procedure is quite simple:

## Factor Scores for the Rasch model
fit <- rasch(LSAT)
factor.scores(fit)

What about Partial Credit Model (PCM)? For PCM I use PCM function from 
eRm package. Is there any similar function like factor.scores to 
estimate ability scores using PCM model?

Best, Andrej