🚀 go-pugleaf

In article <1992Jul22.141833.6229@monu6.cc.monash.edu.au>, map@hal.maths.monash.edu.au (Michael Page) writes:
|> In article <lexier.711772340@sfu.ca> lexier@fraser.sfu.ca (Lyle Lexier) writes:
|> > 
|> >     Is there any software for calculating the differential equation:
|> > 
|> >                    g
|> >          fi  =   - - sin (fi)
|> >            tt      L
|> 
|> First, it's phi not fi.  Second, this can be integrated by multiplying
|> both sides by phi_t, then I recall that the solution is expressible in
|> terms of elliptic functions.  Even without this it is pretty trivial to
|> integrate this numerically with 4th-order Runge Kutta for a pair of
|> first-order o.d.e.s 
|> 
|>             X_t = -g/L sin (Y) and Y_t = X.
|> 
|> My second-year students could do it.
|> 
|> 

Come on, take it easy on the guy.  You don't know what his background is,
or what his field of expertise is.

As long as you told him how to solve the problem with Runge Kutta, why
not answer his original question and tell him where to get the software?

Mail to netlib@ornl.gov with the message
send index from ode
and the message
send index from odepack

I'm sure one of them has an RK4 program.

Bill