# see Thissen, Pommerich, Billeaud, & Williams (1995, Table 2)
spec <- list()
spec[1:3] <- list(rpf.grm(outcomes=4))
param <- matrix(c(1.87, .65, 1.97, 3.14,
2.66, .12, 1.57, 2.69,
1.24, .08, 2.03, 4.3), nrow=4)
# fix parameterization
param <- apply(param, 2, function(p) c(p[1], p[2:4] * -p[1]))
grp <- list(spec=spec, mean=0, cov=matrix(1,1,1), param=param)
sumScoreEAP(grp)
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