factors(8)

NAME
factors - numeric real factorization

CALLING SEQUENCE
[lnum,g]=factors(pol [,'flag'])
[lnum,lden,g]=factors(rat [,'flag'])

PARAMETERS

pol : real polynomial

rat : real rational polynomial (rat=pol1/pol2)

lnum
    : list of polynomials (of degrees 1 or 2)

lden
    : list of polynomials (of degrees 1 or 2)

g   : real number

flag
    : character string 'c' or 'd'

DESCRIPTION
returns the factors of polynomial pol in the list lnum and the "gain" g.

One has pol= g times product of entries of the list lnum. If argument of factors is a 1x1 rational rat=pol1/pol2, the factors of the numerator pol1 and the denominator pol2 are returned in the lists lnum and lden respectively.

The "gain" is returned as g,i.e. one has: rat= g times (product entries in lnum) / (product entries in lden).

If flag is 'c' (resp. 'd'), the roots of pol are refected wrt the imaginary axis (resp. the unit circle), i.e. the factors in lnum are stable polynomials.

Same thing if factors is invoked with a rational arguments: the entries in lnum and lden are stable polynomials if flag is given.