Question on Integrate[ F . Dt[r], ?]
- To: mathgroup at yoda.physics.unc.edu
- Subject: Question on Integrate[ F . Dt[r], ?]
- From: pwm at macaw.jhuapl.edu (Phil W. Miller x8335 1-e138)
- Date: Fri, 7 Feb 92 10:23:01 EST
I posted a question earlier in the week on how to make
Dt[x y, Constants->{x}] give me x Dt[y] like the Mma
reference book says it will. I would like to thank Jack Lee and
David Jacobson for the excellent help.
I am trying to write a general package that will help solve Lagrange's
equations of motion. I am having moderate success, but there is one
major stumbling block to having a good package. That is, what is a
good way to calculate the potential V that is the integral of the
dot product of force and virtual displacement. Does someone know a
general way to integrate this scalar function?
The difficulty lies in picking the variables of integration. For example,
the integrand could be
a) dV1 = x Dt[x] + y Dt[y], or
b) dV2 = x Dt[y] + y Dt[x].
How does one devise a general scheme for integrating such expressions?
Your help is greatly appreciated.
Sincerely,
Phil Miller
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Philip Miller The Johns Hopkins University/Applied Physics Lab
pwm at macaw.jhuapl.edu Johns Hopkins Rd
Laurel, MD 20723-6099
(301) 953-5000 x8335
FAX: (301) 953-1093
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