method

permutation?

v1_9_3_392 - Show latest stable - Class: Matrix

permutation?()

public

Returns true is this is a permutation matrix Raises an error if matrix is not square.

# File lib/matrix.rb, line 668
  def permutation?
    Matrix.Raise ErrDimensionMismatch unless square?
    cols = Array.new(column_size)
    rows.each_with_index do |row, i|
      found = false
      row.each_with_index do |e, j|
        if e == 1
          return false if found || cols[j]
          found = cols[j] = true
        elsif e != 0
          return false
        end
      end
      return false unless found
    end
    true
  end

permutation?

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