FilterMatrix-class: Matrix for Filter Results
Description
A FilterMatrix object is a matrix meant for storing
  the logical output of a set of FilterRules, where
  each rule corresponds to a column. The FilterRules are stored
  within the FilterMatrix object, for the sake of
  provenance. In general, a FilterMatrix behaves like an
  ordinary matrix.
Accessor methods
In the code snippets below, x is a FilterMatrix object. 
    - filterRules(x): Get the- FilterRulescorresponding to the columns of the matrix.
Constructor
    - 
      FilterMatrix(matrix, filterRules): Constructs aFilterMatrix, from a givenmatrixandfilterRules. Not usually called by the user, seeevalSeparately.
Utilities
    - 
      summary(object, discarded = FALSE, percent = FALSE):
      Returns a numeric vector containing the total number of records
      (nrow), the number passed by each filter, and the number of
      records that passed every filter. IfdiscardedisTRUE, then the numbers are inverted (i.e., the values are
      subtracted from the number of rows). IfpercentisTRUE, then the numbers are percent of total.