simp

Arguments

N,D

real polynomials or real matrix polynomials

H

rational matrix (i.e matrix with entries n/d ,n and d real polynomials)

Description

[n1,d1]=simp(n,d) calculates two polynomials n1 and d1 such that n1/d1 = n/d.

If N and D are polynomial matrices the calculation is performed element-wise.

H1=simp(H) is also valid (each entry of H is simplified in H1).

Caution:

-no threshold is given i.e. simp cannot forces a simplification.

-For linear dynamic systems which include integrator(s) simplification changes the static gain. (H(0) for continuous systems or H(1) for discrete systems)

-for complex data, simp returns its input(s).

-rational simplification is called after nearly each operations on rationals. It is possible to toggle simplification on or off using simp_mode function.

Examples

s=poly(0,'s');
[n,d]=simp((s+1)*(s+2),(s+1)*(s-2))

simp_mode(%F);hns=s/s
simp_mode(%T);hns=s/s

See also

• roots — roots of polynomials
• trfmod — poles and zeros display
• poly — polynomial definition
• clean — cleans matrices (round to zero small entries)
• simp_mode — toggle rational simplification