Fagner Araujo wrote on 11/07/2005 02:12:26 PM:
> Hey,
> my name is Fagner Araujo, I'm Braziliam.
> I need a method in Maxima to make variable
> separation in form:
> y * s^2 + 3 * y = x * s + x * s^3 + 4*x
>
> x s^3 + s + 4
> --- = -------------------
> x x^2 + 3
>
> This is for use in transfer function calculation for
> process control systems.
> Do you know how to do this in Maxima ??
>
> Thanks.
> Fagner Araujo.
>
Maybe you want to do something like:
(%o4) s^2*y+3*y=s^3*x+s*x+4*x
(%i5) ratsubst(z, x/y,%);
(%o5) (s^2+3)*y=s^3*y*z+s*y*z+4*y*z
(%i6) solve(%,z);
(%o6) [z=(s^2+3)/(s^3+s+4)]
(%i7) subst(x/y,z,%);
(%o7) [x/y=(s^2+3)/(s^3+s+4)]
Maybe you are looking for a general scheme that would
automatically separate variables in a from similar to
(%o7)? That would take some thought, I think.
Welcome to Maxima.
Barton