[R-sig-ME] data layout for crossed factors w/interaction in linear mix models
bates at stat.wisc.edu
Fri Aug 21 23:01:58 CEST 2009
On Fri, Aug 21, 2009 at 2:22 PM, Rafael Diaz<tuteson at yahoo.com> wrote:
> Dear All,
> I am trying to fit a simple linear mixed model (see below
> this paragraph) arising from a crossed factorial design with
> 2 factors and ubalanced number of replicates (from two to
> five) in each cell, but I keep getting an error message (see
> bottom of message). The model is:
> yijk = intercept + ai + bj + abij + ejik, where:
> "intercept" is fixed, and the crosss factors, ai, i =
> 1,..,10, and bj, j= 1,..,10, are random. I am
> interested in estimating the variance components of these
> factors AND their interaction. I have tried:
> fm1 <- lmer(formula = V1~1 + (1|V2) + (1|V3) + (1|V4),
> data = 'datos') using two types of data layout for "
We will need more information before we can help you. It is best if
you can make the data available in some form. Otherwise, please
include the results of
fm1 <- lmer(V1 ~ 1 + (1|V2) + (1|V3) + (1|V4), datos)
and, if the error still occurs,
> 1) using a matrix with 3 columns:
> y intercept ai's bj's abij's
> y111 1 1 1 1 (1x1)
> y112 1 1 1 "
> y121 1 1 2 2 (1x2)
> y122 1 1 2 "
> y123 1 1 2 "
> y131 1 1 3 3 (1x3)
> . . . . .
> . . . . .
> 2) using the design matrix from Y = XBeta +Zb.
> That is, using the same first two columns as above, but
> substituting 1020 columns (10 for ai's, 10 for bj's and 100
> for abij's) for the last three columns.
> I get the message: "Error in eval(predvars, data, env) :
> invalid envir argument"
> Is my data layout mispecified? Do I need to input initial
> values for the random components in order to get the REML
> estimates? I lmer valid for unbalanced designs? Any help would be greatly appreciated.
> Rafael Diaz
> California State University Sacramento
> Math and Stats
> R-sig-mixed-models at r-project.org mailing list
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