[R] Row mean scores differ

[Tobias Verbeke]

>Suppose that we have o 2-D contingency table where the row variable is nominal and the column one is ordinal. In SAS it is possible to compute the statistic named as row mean scores differ. How can we programmed it in R? 
>(See also Aggresti (2002), Categorical Data Analysis, p. 302)

There is a chapter by chapter R / S-PLUS companion to Agresti (2002) 
by Laura Thompson at

https://home.comcast.net/~lthompson221/Splusdiscrete2.pdf

HTH,
Tobias