Check a Design for Balance

DESCRIPTION:

Check the design of the experiment or study for balance.

USAGE:

isBalanced(object, countOnly, level) 

REQUIRED ARGUMENTS:

object
A groupedData object containing a data frame and a formula that describes the roles of variables in the data frame. The object will have one or more nested grouping factors and a primary covariate.
countOnly
A logical value indicating if the check for balance should only consider the number of observations at each level of the grouping factor(s). Defaults to FALSE.
level
an optional integer vector specifying the desired prediction levels. Levels increase from outermost to innermost grouping, with level 0 representing the population (fixed effects) predictions. Defaults to the innermost level.

VALUE:

TRUE or FALSE according to whether the data are balanced or not

SEE ALSO:

,

EXAMPLES:

isBalanced(Orthodont)                    # should return TRUE 
isBalanced(Orthodont, countOnly = TRUE)  # should return TRUE 
isBalanced(Pixel)                        # should return FALSE 
isBalanced(Pixel, level = 1)             # should return FALSE