[R] How to plot results of clmm()?

[thomas]

Dear list,

I'd like to create a visual plot of a clmm() I've fitted using the 
'ordinal' package in R. It's possible to do this with a glm() by using 
the 'effects' package. For example:

    library(effects)
    data(BEPS)
    mod <- lm(political.knowledge ~ age + gender + vote, data=BEPS)
    eff <- effect("age", mod, default.levels=100)
    plot(eff, colors=c("black", "red"))

Produces: http://i.stack.imgur.com/elo4p.png

The 'effects' package does not support clmm:

    mod <- clmm(as.factor(political.knowledge) ~ age + gender + 
(1|vote), data=BEPS)
    eff <- effect("age", mod, default.levels=100)
    > Error in UseMethod("effect", mod) :
    no applicable method for 'effect' applied to an object of class "clmm"

How would I go about doing this? I can't find any examples with clm() or 
clmm() online. Any suggestions would be much appreciated.

Tom