Re: Can Mathematica Do This?
- To: mathgroup at smc.vnet.net
- Subject: [mg8181] Re: Can Mathematica Do This?
- From: fahad at cs.pitt.edu (Fahad A Hoymany)
- Date: Mon, 18 Aug 1997 03:07:05 -0400
- Organization: Univ. of Pittsburgh Computer Science
- Sender: owner-wri-mathgroup at wolfram.com
Fahad A Hoymany (fahad at cs.pitt.edu) wrote: : Before I go on to investigate this problem, and because I'm not : familiar with the capability of Mathematica, could someone tell me if : Mathematica can: : 1) Find the partial derivative of a function of three variables, f(x,y,z), : with respect to each variable? : 2) Find the minimum (x,y,z) for f? : The function f is not very complicated, involving only first and second : order expressions in x,y, and z. : I'd very much appreciate a "yes" or "no" answer. Thanks to those who e-mailed me with some suggestions. Although, I am now a little more familiar with Mathematica, the problem I need to solve seems to be too tough for Mathematica, even though it "looks" like a simple problem. I tried FindMinimum, NDsolve, among other attempts, and I either get an error of the form ".... something is not a real number", or Mathematica takes the command but never returns an answer! Here is the problem in case some kind soul wants to give it a try: Find the minimum of f in c and h f = (c d1+d2) r (2/((c+1) (h-c+1))) + d3 h/2 + (c d4+d5) r (2/((c+2)*(h-c+1))) Note that c <= h, and c,h >=0. If it helps, h < 10,000. The d's are real numbers in the range 0 to 1.0, and r is real in the range 0 to 100,000. Best regards Fahad