Nestwhile

• To: mathgroup at smc.vnet.net
• Subject: [mg57201] Nestwhile
• From: Pratik Desai <pdesai1 at umbc.edu>
• Date: Fri, 20 May 2005 04:44:10 -0400 (EDT)
• Sender: owner-wri-mathgroup at wolfram.com

```Hi,
I am having problem with using NestWhile in a code which basically boils
down to finding values for the variables (e,dw)  for which a function
d[e, dw] is "minimized" while one variable (e) goes up to 1. I have been
using the following approach, which unfortunately loops for 1
iteration..There is definitely a better probably a simpler  way to do

Here is the attempt :

d[ e, dw] =
Abs[0. + 1143.8189785870038/((-2.0224920432639264 +
e)*(22.50249204326393 + e)) +
(e^3*(-2.3561944901923435 -
1.3322676295501878*^-15*w))/((-2.0224920432639264 +
e)*(22.50249204326393 + e)) -
56.548667764616276*w - (2573.5927018207585*dw)/((-2.0224920432639264
+ e)*(22.50249204326393 + e)) +
(e^2*(-73.38760438785755 +
56.54866776461624*dw))/((-2.0224920432639264 + e)*(22.50249204326393 +
e)) +
(e*(-407.4855111216201 +
1158.1167158193412*dw))/((-2.0224920432639264 + e)*(22.50249204326393 +
e))] +
8.*Abs[0. + 0./((-2.0224920432639264 + e)*(22.50249204326393 + e)) +
(0.*dw)/((-2.0224920432639264 + e)*(22.50249204326393 + e)) +
e^2*(0./((-2.0224920432639264 + e)*(22.50249204326393 + e)) +
(0.*dw)/((-2.0224920432639264 + e)*
(22.50249204326393 + e))) + e*(0. + 0./((-2.0224920432639264 +
e)*(22.50249204326393 + e)) +
(0.*dw)/((-2.0224920432639264 + e)*(22.50249204326393 + e)))] +
Abs[0. + (e*(-107.23302924253159 -
7.105427357601*^-14*dw))/((-2.0224920432639264 + e)*(22.50249204326393 +
e)) +
(e^3*(2.3561944901923453 -
4.440892098500626*^-16*dw))/((-2.0224920432639264 +
e)*(22.50249204326393 + e)) +
e^2*(48.25486315913923/((-2.0224920432639264 + e)*(22.50249204326393
+ e)) +
(0.*dw)/((-2.0224920432639264 + e)*(22.50249204326393 + e)))]

Module[{e = 0.05, dw = 0.04}, NestWhile[{e += 0.01,dw += 0.1},
d[ e, dw],10^-2 <d[ e,  dw] <0&&e==1 ]; Print[dw,d[ e, dw],e];
Return[d[j, e, dw], Module]]

0.14
25.415

--
Pratik Desai
UMBC
Department of Mechanical Engineering
Phone: 410 455 8134

```

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