numVar: Numerical variables. When several variables, only first is used.
x: Model matrix generated by parent function
maxN: Primary suppression when number of contributors <= maxN.
protectZeros: Suppression parameter. Only TRUE (default) is used implemented.
charVar: Variable(s) with contributor codes. When empty, unique contributor in each row is assumed. When several variables, see details.
removeCodes: Vector of codes to be omitted when counting contributors. With empty charVar row indices are assumed and conversion to integer is performed.
remove0: When set to TRUE (default), data rows in which the first numVar (if any) is zero are excluded from the count of contributors. Alternatively, remove0 can be specified as one or more variable names. In this case, all data rows with a zero in any of the specified variables are omitted from the contributor count. Specifying remove0 as variable name(s) is useful for avoiding warning when there are multiple numVar variables.