Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2005
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2005

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

Search the Archive

Re: Time needed for calculation

  • To: mathgroup at smc.vnet.net
  • Subject: [mg62427] Re: [mg62411] Time needed for calculation
  • From: "David Park" <djmp at earthlink.net>
  • Date: Thu, 24 Nov 2005 06:33:25 -0500 (EST)
  • Sender: owner-wri-mathgroup at wolfram.com

Fujio,

Try out ImplicitPlot with two iterators. You equation was missing a
parenthesis and I made an assumption about where it should be. Look over a
wider domain to begin with. Then maybe you can zoom in on the part you want.
Sometimes it helps to evaluate equations before you put them into
ImplicitPlot, just so you can better see what you are dealing with.

<< Graphics`ImplicitPlot`

L = 48;
a = 0.1;
A = 1;
r = 0.1;
t = 0.046296296296296294`;

eqn = A*r*L*(1 - a)*((1 - t)*c*k^a) ==
   (a + (1 - a)*(1 - t))*L^2*(1 - a)^2*(1 - t)^3*
     k^(3*a - 1) + L*(1 - a)*c*(1 - t)*
     ((-A)*(a + (1 - a)*(1 - t))*(2 - t) -
      (1 - a)*(1 - t)^2 + A*a*(1 - t))*k^(2*a - 1) +
    A*c^2*(A*(a + (1 - a)*(1 - t)) +
      (1 - a)*(1 - t) - A*a*(1 - t))*k^(a - 1) +
    A^2*r*c^2

4.120000000000001*c*k^0.1 ==
  0.1*c^2 + (1.7212962962962965*c^2)/k^0.9 -
   (106.93561728395063*c)/k^0.8 + 1551.4025308641978/
    k^0.7

ImplicitPlot[eqn, {k, 1, 300}, {c, 0, 100},
  AspectRatio -> 1]

ImplicitPlot[eqn, {k, 0.8, 1.5}, {c, 15, 50},
  AspectRatio -> 1]

Those evaluate almost instantly.

David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/

From: JikaiRF at AOL.COM [mailto:JikaiRF at AOL.COM]
To: mathgroup at smc.vnet.net



Dear Sirs,
I have some questions about how long a computer can calculate, without
damages on hard wear.
More specifically speaking, I intend to depict trajectories on (k, c) axis,
which are derived from programming on Mathematica.
My program is as follows:

<< Graphics`ImplicitPlot`
L = 48;

a = 0.1;

A = 1;

r = 0.1;

t = 0.046296296296296294`;

ImplicitPlot[A r L (1 - a)((1 -t) c k^a == (a+(1-a)(1- t)) L^2 (1-a)^2 (1- t
)^3 k^(3a-1)
                     +L(1-a) c (1- t) (-A(a+(1-a)(1- t))(2- t)-(1-a)(1- t)^2
+A a(1- t)) k^(2a-1)
                     +A c^2 (A(a+(1-a)(1- t))+(1-a)(1- t) -A a(1- t))
k^(a-1)
+A^2 r c^2, {k, 0.8, 1.5}]

This program seems to work well.   However, I cannot obtain the curve which
should be derived from the above program, though my computer continues to
calculate more than fifteen minutes.

I would like to know how   long a computer can calculate without damages on
hardware, and additionally how long it takes to obtain the required curve
based
on my computer.
Especially, my computer is PowerBook G4 with 1.5 GHz processor.

     Sincerely,
     Fujio Takata.




  • Prev by Date: Re: permutations
  • Next by Date: Re: Time needed for calculation
  • Previous by thread: Re: Time needed for calculation
  • Next by thread: Re: Time needed for calculation