Re: Re: Calculating Gradients of Vector Functions
- To: mathgroup at smc.vnet.net
- Subject: [mg41196] Re: [mg41172] Re: Calculating Gradients of Vector Functions
- From: "Eric L. Strobel" <fyzycyst at comcast.net>
- Date: Wed, 7 May 2003 03:51:07 -0400 (EDT)
- Reply-to: fyzycyst at mailaps.org
- Sender: owner-wri-mathgroup at wolfram.com
on 05/06/03 6:02 AM, Paul Abbott at paul at physics.uwa.edu.au wrote: > At http://w3.pppl.gov/~hongqin/computerAlgebra.htm you will find reference to > a Mathematica Symbolic Vector Analysis package developed by Hong Qin. I > have made a few minor changes to his Package (correcting some > formatting bugs) and put his Package, Notebooks, and PDF files at > > http://www.physics.uwa.edu.au/pub/Mathematica/Calculus/ > > I suggest putting GeneralVectorAnalysis.m into a folder called Calculus > in the directory returned by evaluating $UserAddOnsDirectory. Maybe I'm just slow. (More likely that I haven't had a concentrated block of time to pursue this, and I've never really delved into Mathematica programming before...) But the three things I'd really like to do with that package (and can't quite figure out) are: gradient of a vector function, such as the gravity gradient; time derivatives, i.e., where the unit vectors are necessarily changing with time; and possibly the Lagrangian total time derivative, namely partial-t + vector-v X del . Now, the first two, IIRC from way back in grad school when I did my General Relativity, are aspects of the covariant derivative. The "covariant derivative" in this package, though, is really a directional derivative. I've been tinkering with this, but, as I say, I've not had the time I really need to both climb the learning curve on how to extend this package and then implement what I want. I suspect that if the first two of my 'wants' get handled, then the third should be trivial. So, any pointers or hints (or worked solutions :-) ) would be welcome. - Eric. -- Eric Strobel (fyzycyst at NOSPAM^mailaps.org) ===================================================================== Fight political correctness! Speak the truth!!! =====================================================================