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MATLAB Central > MATLAB Newsreader > (fsolve) + (Scaling): Possibly Simple Problem  Ur... 

Subject: (fsolve) + (Scaling): Possibly Simple Problem  Urgent Help Needed From: Alaa Elwany Date: 9 Nov, 2011 20:29:11 Message: 1 of 16 
I am trying to solve 2 nonlinear equations in two variables x1, and x2. 
Subject: (fsolve) + (Scaling): Possibly Simple Problem  Urgent Help Needed From: Roger Stafford Date: 9 Nov, 2011 21:47:28 Message: 2 of 16 
"Alaa Elwany" <alaa_elwany@yahoo.com> wrote in message <j9enqn$r4o$1@newscl01ah.mathworks.com>... 
Subject: (fsolve) + (Scaling): Possibly Simple Problem  Urgent Help Needed From: Alaa Elwany Date: 9 Nov, 2011 22:10:31 Message: 3 of 16 
Thank you very much for your response Roger. However, being familiar with this "Starting Solution" dilemma, I did have a validation problem instance, for which I knew in advance that the solution is x1 = 1.2e23, x2=8.2 I set the starting solution to: 
Subject: (fsolve) + (Scaling): Possibly Simple Problem  Urgent Help Needed From: Greg Heath Date: 9 Nov, 2011 23:29:51 Message: 4 of 16 
On Nov 9, 5:10 pm, "Alaa Elwany" <alaa_elw...@yahoo.com> wrote: 
Subject: (fsolve) + (Scaling): Possibly Simple Problem  Urgent Help Needed From: Mark Shore Date: 10 Nov, 2011 00:12:28 Message: 5 of 16 
"Alaa Elwany" <alaa_elwany@yahoo.com> wrote in message <j9enqn$r4o$1@newscl01ah.mathworks.com>... 
Subject: (fsolve) + (Scaling): Possibly Simple Problem  Urgent Help Needed From: Roger Stafford Date: 10 Nov, 2011 00:38:10 Message: 6 of 16 
"Alaa Elwany" <alaa_elwany@yahoo.com> wrote in message <j9eton$ia1$1@newscl01ah.mathworks.com>... 
Subject: (fsolve) + (Scaling): Possibly Simple Problem  Urgent Help Needed From: Roger Stafford Date: 10 Nov, 2011 00:50:30 Message: 7 of 16 
"Mark Shore" wrote in message <j9f4tc$ab2$1@newscl01ah.mathworks.com>... 
Subject: (fsolve) + (Scaling): Possibly Simple Problem  Urgent Help Needed From: Mark Shore Date: 10 Nov, 2011 03:43:10 Message: 8 of 16 
"Roger Stafford" wrote in message <j9f74m$gkv$1@newscl01ah.mathworks.com>... 
Subject: (fsolve) + (Scaling): Possibly Simple Problem  Urgent Help Needed From: Alaa Elwany Date: 10 Nov, 2011 14:17:30 Message: 9 of 16 
Again, thank you very much for your concern Roger. 
Subject: (fsolve) + (Scaling): Possibly Simple Problem  Urgent Help Needed From: Alaa Elwany Date: 10 Nov, 2011 14:19:14 Message: 10 of 16 
Thanks a lot Greg. I would like to try your scaling suggestion, but I am not sure how I can implement this in my code. You said "Make the replacement x1 = 1e23*x3". Do you mean I should regard x3 and x4 as my variables, solve the equation, then transform back to x1 and x2 after I solve? Please advise. 
Subject: (fsolve) + (Scaling): Possibly Simple Problem  Urgent Help Needed From: Roger Stafford Date: 10 Nov, 2011 16:31:11 Message: 11 of 16 
"Mark Shore" wrote in message <j9fh8e$fdu$1@newscl01ah.mathworks.com>... 
Subject: (fsolve) + (Scaling): Possibly Simple Problem  Urgent Help Needed From: Roger Stafford Date: 10 Nov, 2011 16:34:14 Message: 12 of 16 
"Alaa Elwany" <alaa_elwany@yahoo.com> wrote in message <j9gmdq$54r$1@newscl01ah.mathworks.com>... 
Subject: (fsolve) + (Scaling): Possibly Simple Problem  Urgent Help Needed From: Alaa Elwany Date: 10 Nov, 2011 18:10:34 Message: 13 of 16 
THANK YOU! WORKED! 
Subject: (fsolve) + (Scaling): Possibly Simple Problem  Urgent Help Needed From: Greg Heath Date: 11 Nov, 2011 07:01:24 Message: 14 of 16 
On Nov 10, 9:19 am, "Alaa Elwany" <alaa_elw...@yahoo.com> wrote: 
Subject: (fsolve) + (Scaling): Possibly Simple Problem  Urgent Help Needed From: Greg Heath Date: 11 Nov, 2011 07:12:54 Message: 15 of 16 
On Nov 9, 7:12 pm, "Mark Shore" <msh...@magmageosciences.ca> wrote: 
Subject: (fsolve) + (Scaling): Possibly Simple Problem  Urgent Help Needed From: Mark Shore Date: 11 Nov, 2011 19:25:29 Message: 16 of 16 
> Greg Heath 
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