lmeLevel-class {lme4} | R Documentation

## Class "lmeLevel"

### Description

An object representing a single level of random effects in a linear mixed-effects model.

### Objects from the Class

Objects can be created by calls of the form `new("lmeLevel", ...)` or by calls to the generic constructor `lmeLevel`.

### Slots

`precision`:
  A precision matrix of class `"pdMat"`
`groups`:
  The grouping factor (of class `"factor"`) for the level.
`columns`:
  An `"integer"` vector of the columns in the model matrix that correspond to this level.
`parsInd`:
  An `"integer"` vector giving the subscripts in the overall parameter vector that apply to this level.
`originalRows`:
  A list of integer vectors of row numbers in the original model matrix that correspond to each of the levels of the grouping factor.
`decomposedRows`:
  A list of integer vectors of row numbers in the decomposed model matrix that correspond to each of the levels of the grouping factor.
`storedRows`:
  A list of integer vectors of row numbers in the stored data matrix that correspond to each of the levels of the grouping factor.
`nrow`:
  `integer`: the number of rows in the precision matrix.
`updateFactor`:
  Object of class `"matrix"` - the matrix `A` used to evaluate the gradient of the log-likelihood and to formulate the ECME step.
`hessianArray`:
  Object of class `"array"` - the array `H` used to evaluate the Hessian of the log-likelihood.
`nlev`:
  `integer`: the number of levels in the grouping factor

### Methods

EMupdate<-
  `signature(x = "lmeLevel", nlev = "missing", value = "matrix")`: update the level within the EM or ECME algorithm
LMEgradient
  `signature(x = "lmeLevel", A = "matrix", nlev = "missing")`: calculate the gradient of the log-likelihood with respect to the parameters from the decomposition of the scaled BLUPs and their variances.
coef
  `signature(object = "lmeLevel")`: extract the parameters (from the precision matrix)
coef<-
  `signature(object = "lmeLevel", value = "numeric")`: set the parameters.

### Note

In `reStruct` objects the random-effects terms and the fixed-effects terms and the response are all represented by `lmeLevel` objects. The `precision` slot in the fixed-effects and response objects is an uninitialized `pdMat` objects and the `nrow` slot is zero.

### Author(s)

Saikat DebRoy saikat@stat.wisc.edu and Douglas Bates bates@stat.wisc.edu

### See Also

`lmeLevel`

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