MathGroup Archive 2003

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Another plea for help...

  • To: mathgroup at smc.vnet.net
  • Subject: [mg39210] Re: Another plea for help...
  • From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
  • Date: Tue, 4 Feb 2003 02:21:08 -0500 (EST)
  • Organization: Universitaet Leipzig
  • References: <b1f6h6$ara$1@smc.vnet.net>
  • Reply-to: kuska at informatik.uni-leipzig.de
  • Sender: owner-wri-mathgroup at wolfram.com

Hi,

and

result = Solve[{a == 1/(1/r2 + 1/50), 50 == 1/(1/(a + r1) + 1/r2)}, r1,
a]
Plot[Evaluate[r1 /. result], {r2, -25, 25}]

works fine.

Regards
   Jens

"1.156" wrote:
> 
> I'd sure like to find out how to clean up a process I do a lot.  Namely, get
> a solution to some set of equations and then plot the result. For example,
> I recently did
> 
> result = Solve[{a == 1/(1/r2 + 1/50), 50 == 1/(1/(a + r1) + 1/r2)}, r1, a]
> 
> This gives {{r1 -> (a function of r2)  }}
> 
> Then, I plot it by
> Plot[ (this function of r2), {r2, startvalue, stopvalue}]
> 
> where I carefully type in this function.  I feel sure you Mathematica pros
> don't have to do that so I have made several feeble attempts to automate
> this over the years. They fail because I still don't have a clue how Mathematica works.
> 
> Here's my last attempt:
> Plot[ result /. %]
> Mathematica just hisses and prints out tons of error messages, none of which mean
> a thing to me.
> 
> Surely there is a way to get this plot without having to type the Solve[] result
> into Plot[].  Any hints would be appreciated, as usual.
> 
> Rob


  • Prev by Date: Re: Problem with NIntegrate -- Monte Carlo
  • Next by Date: Re: Fit or Interpolate
  • Previous by thread: Re: Another plea for help...
  • Next by thread: perate matrix of derivations