On Fri, 13 Nov 2009, Julie Sandberg wrote:
< Hi,
<
< I am working on a dynamaics assigment using Maxima. I need to ultimately solve for forces and moments, but throughout my script Maxima creates nested lists with excessive [ and ]'s where I should have simple matrices. For instance, in the attached code, I calculate a MOI integrand using
<
< /*MOI Integrand*/
< integ:(r.r)*ident(3)-transpose(r).r;
<
< Then, I would like to convert these values to cylindrical coordinates:
<
< /*Use Clyindrical Coordinates*/
< integ2:ev(integ,x=u*r*sin(theta),y=h,z=u*r*cos(theta)),expand,ratsimp,trigsimp;
Julie, if I understand your problem correctly, then [u,h,theta] are
cylindrical coordinates, while you define r:[x,y,z] a few lines above in
the attached .mac file. It seems to me that you should not have 'r' in
the above substitutions.
integ2:ev(integ,x=u*sin(theta),y=h,z=u*cos(theta)),expand,ratsimp,trigsimp;
I suspect this is the root of your problem below.
Leo
<
< Because integ is a nested list, ev cannot evaluate at these values. Is there any way to "un-nest" integ? I have this same problem through my code.
<
< Thank you for your time.
<
< --
< Julie Sandberg
< M.S. Aerospace Engineering
< Dynamics and Control
< Texas A&M University
<
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