dear all,
i am analyzing data of a cluster-randomized trial via lme. when calling
a.lme <- lme(data = emm.stat, random = ~weeks | code, fixed = v6.a ~
weeks * as.factor(group.fi), na.action = na.omit)
everything is fine, but cluster structure is ignored; so I call
b.lme <- lme(data = emm.stat, random = ~weeks | code, fixed = v6.a ~
weeks * as.factor(group.fi), cluster =~ as.factor(cs.group), na.action
= na.omit)
but get this error message
> b.lme <- lme(data = emm.stat, random = ~ weeks | code, fixed = v6.a ~
weeks *
as.factor(group.fi), cluster = ~ as.factor(cs.group), na.action
=
na.omit)
Problem in lme: argument cluster= not matched: lme(data = emm.stat,
random = ~ weeks | code, fixed = v6.a ~ weeks *
as.factor(group.fi), cluster = ~ as.factor(cs.group), na.action
=
na.omit)
Use traceback() to see the call stack
any help would be highly appreciated.
best wishes
bernd
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