2.4.1 Rational polynomial simplification

Scilab automatically performs pole-zero simplifications when the the built-in primitive simp finds a common factor in the numerator and denominator of a rational polynomial num/den. Pole-zero simplification is a difficult problem from a numerical viewpoint and simp function is usually conservative. When making calculations with polynomials, it is sometimes desirable to avoid pole-zero simplifications: this is possible by switching Scilab into a ``no-simplify'' mode: help simp_mode. The function trfmod can also be used for simplifying specific pole-zero pairs.