Simplifying Matrix Product
- To: mathgroup at smc.vnet.net
- Subject: [mg20695] Simplifying Matrix Product
- From: tsao_please_dont_send_spam at its.caltech.edu
- Date: Sun, 7 Nov 1999 02:10:22 -0500
- Organization: California Institute of Technology, Pasadena
- Sender: owner-wri-mathgroup at wolfram.com
I'm having a little trouble simplifying a product of two matrices on
Mathematica 3.0 for Solaris and Linux. My two matrices are
DERR = {{-(psidot*Cos[psi]*Sin[gamma]) +
Cos[psi]*(-(gammadot*Cos[phi]*Sin[gamma]) -
phidot*Cos[gamma]*Sin[phi]) - gammadot*Cos[gamma]*Sin[psi] -
psidot*Cos[gamma]*Cos[phi]*Sin[psi],
-(gammadot*Cos[gamma]*Cos[psi]) -
Cos[psi]*(-(gammadot*Cos[phi]*Sin[gamma]) -
phidot*Cos[psi]*Sin[phi]) + psidot*Cos[gamma]*Cos[phi]*Sin[psi] +
psidot*Sin[gamma]*Sin[psi],
phidot*Cos[gamma]*Cos[phi] - gammadot*Sin[gamma]*Sin[phi]},
{(-(phidot*Cos[gamma]*Cos[phi]) + gammadot*Sin[gamma]*Sin[phi])*
(gammadot*Cos[gamma]*Cos[psi] +
Cos[psi]*(-(gammadot*Cos[phi]*Sin[gamma]) -
phidot*Cos[psi]*Sin[phi]) - psidot*Cos[gamma]*Cos[phi]*Sin[psi] -
psidot*Sin[gamma]*Sin[psi]),
(phidot*Cos[phi]*Sin[gamma] + gammadot*Cos[gamma]*Sin[phi])*
(gammadot*Cos[psi]*Sin[gamma] + psidot*Cos[phi]*Cos[psi]*Sin[gamma] +
psidot*Cos[gamma]*Sin[psi] +
(gammadot*Cos[gamma]*Cos[phi] - phidot*Sin[gamma]*Sin[phi])*Sin[psi]),
phidot*Sin[phi]*(phidot*Cos[phi]*Sin[gamma] +
gammadot*Cos[gamma]*Sin[phi])}}
INVR = {{Cos[gamma]*Cos[phi]*Cos[psi] - Sin[gamma]*Sin[psi],
Cos[psi]*Sin[gamma] + Cos[gamma]*Cos[phi]*Sin[psi],
-(Cos[gamma]*Sin[phi])}, {-(Cos[phi]*Cos[psi]*Sin[gamma]) -
Cos[gamma]*Sin[psi], Cos[gamma]*Cos[psi] -
Cos[phi]*Sin[gamma]*Sin[psi], Sin[gamma]*Sin[phi]},
{Cos[psi]*Sin[phi], Sin[phi]*Sin[psi], Cos[phi]}}
I type in the following...
FullSimplify[ DERR . INVR ]
...and the UltraSPARC-60 has been chugging for about 12 hours now. Any
ideas??
Cheers,
Phil