replications
Number of Replications of Terms

### Description

Returns a vector or a list of the number of replicates for each term in the formula.

### Usage

    replications(formula, data = NULL, na.action)

### Arguments

formula | a formula, a terms object, or a data frame. If a data frame, then data need not be given, and the formula "~ ." is implied.
data | a data frame. If data is not given, the search list is used to find the objects in formula. Usually a data frame should be attached when data is not given.
na.action | a function that specifies how missing values are handled. The default is the "na.action" attribute of data first, and then setting option of "na.action", or na.fail, if it is not set in cases.

### Details

A test for balance is (!is.list(replications(formula,data))).
Value
returns a vector or a list whose length is the number of terms in formula.

- If all of the levels in each of the terms are replicated the same number of times, then replications returns a vector containing the number of replicates for each term.
- Otherwise, replications returns a list containing the information on replication, with one component for each term: An unbalanced main effect is a vector, an unbalanced two-factor interaction is a matrix, and so on.

See Also
aov.genyates, raov.
Examples

    replications(post.mean ~ maskdim*spinsp, Sdatasets::wafer)
    ##        maskdim         spinsp maskdim:spinsp
    ##              9              6              3
    replications(Sdatasets::solder[,1:5])
    ## $Opening
    ## [1] 300
    ##
    ## $Solder
    ## [1] 450
    ##
    ## $Mask
    ## Mask
    ## A1.5   A3   A6   B3   B6
    ##  180  270   90  180  180
    ##
    ## $PadType
    ## [1] 90
    ##
    ## $Panel
    ## [1] 300

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