Newbie Question



> I am an electrical engineer newly trying out Maxima to manipulate control
> system and filter equations.? Part of the manipulation is to form the
> equation into an "engineer readable" format.? The following has me stumped
> (b subscript n is written b_n):
>
> Given an equation of the form
> (b_n*s^n + b_(n-1)*s^(n-1) + .... b_1*s + b_0) / (a_n*s^n +
> a_(n-1)*s^(n-1) + .... a_1*s + a_0),
> how
> would I go about dividing the numerator and denominator by a_n (such
> that the s^n term in the denominator is always multiplied by 1)?
>
> Neither a_n nor the value of n is known beforehand.
>
> I have spent several hours trying to find Maxima operators to perform the
> needed division (or supportive operations) and am not finding what I need.
>
>
>
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>

Hi,

I have written a Maxima package for control engineering,
COMA (COntrol engineering with MAxima),
the current link is
    http://www.austromath.at/daten/maxima/zusatz/coma.mac
English documentation is
    http://www.austromath.at/daten/maxima/zusatz/coma_e.pdf

It contains the function "standard_form" which presumeably performs
the desired calculation:

    standard_form(any_transfer_function,3)

Regards
Wilhelm Haager
wilhelm.haager at htlstp.ac.at