Re: Problem in Dot Product of 4x4 Matrices with

*To*: mathgroup at smc.vnet.net*Subject*: [mg95012] Re: [mg95003] Problem in Dot Product of 4x4 Matrices with*From*: DrMajorBob <btreat1 at austin.rr.com>*Date*: Sat, 3 Jan 2009 05:54:14 -0500 (EST)*References*: <200901021155.GAA09238@smc.vnet.net>*Reply-to*: drmajorbob at longhorns.com

Chop[] the matrix. Bobby On Fri, 02 Jan 2009 05:55:19 -0600, Arda Aytekin <ardaaytekin at hotmail.com> wrote: > Hello, > > I'm a student studying in the Mechanical Engineering Department of > Technical University of Istanbul (ITU). > > I'm having problems in Mathematica. I use Mathematica for analyzing a > KUKA robot. First, I have to define related reference frames on the > robot's links according to DH, and then, I have to find the > transformation matrix that maps end-effector {E} to base {0}. When I try > to write the transformation matrix between the first two links (a dot > product of three 4x4 matrices (1 translation + 2 rotations)), > Mathematica writes the products of zero and some transcendental > functions like "0.Sin[\[Theta]]", which, in turn, results in a HUGE > resultant matrix. > > I'm wondering if and/or how I can make Mathematica cancel the related > products.. I mean, I don't want any terms multiplied by zero to appear > in my resultant matrix. > > Thank you for your help.. > -- DrMajorBob at longhorns.com