winBugsRaggedArray {glmmBUGS} | R Documentation |
Suitable for unbalanced data.
winBugsRaggedArray(data, effects = names(data)[-length(names(data))], covariates = NULL, observations = names(data)[length(names(data))], returnData = FALSE)
data |
A data frame containing the response, covariates, and group membership. |
effects |
A vector of character strings containing the grouping levels, from most general to most specific. Defaults to the column names of data, excluding the last column. |
covariates |
A list with names corresponding to effects and each element being a vector of covariates applicable at that level |
observations |
A character string giving the column of observations, or a vector where the first element is the observations and the remaning are offsets. |
returnData |
If true, returns the re-ordered data frame as well as the data frame |
This funciton creates a list of data suitable for passing to the bugs
function, suitable for implimentation as a ragged array. The output can be passed to getStartingValues
to manipulate the output from glmmPQLstrings
, and to restoreParams
to restore the original parametrisation from bugs output.
A list with the following components
Nxx |
The number of levels in the most general groupping |
Syy |
Indexing sequences, one for each level. If yy is level n, level n+1 has elements Syy[1] to Syy[2]-1 belonging to the first category of level n. |
Xyy |
Matrix or vector of covariates belonging to level yy |
|
vector of observations. |
Patrick Brown, patrick.brown@utoronto.ca
"Handling unbalanced datasets" in the "Tricks: Advanced Use of the BUGS Language" section of the bugs manual, at \url{http://mathstat.helsinki.fi/openbugs/data/Docu/Tricks.html#HandlingUnbalancedDatasets}
library(nlme) data(Muscle) muscleRagged = winBugsRaggedArray(Muscle, effects="Strip", observations="conc", covariates=list(observations="length"))