Returns the determinant of
A, calculated efficiently from the factorization.
# File lib/matrix/lup_decomposition.rb, line 78
def det
if (@row_size != @col_size)
Matrix.Raise Matrix::ErrDimensionMismatch unless square?
end
d = @pivot_sign
@col_size.times do |j|
d *= @lu[j][j]
end
d
end