0
|
4875 Views
|
5 Replies
|
3 Total Likes
View groups...
Share
GROUPS:

# ComplexExpand_NSolve_Problem

Posted 9 years ago
 Hello, I am facing problem in ComplexExpand with NSolve for 3 variables, as shown in the attached file. Please suggest me . thanks Attachments:
5 Replies
Sort By:
Posted 9 years ago
 Hello Sir,As you suggested the command , that was really helpful for me but now again facing problem in the case of 5-variables, please see the file in attachment. When i run the file for the case of system of 5 equations with 5 variables, my system gets stuck and stop working, please suggest me.Thanks Attachments:
Posted 9 years ago
 It's probably outside what NSolve methods can handle. Might try using FindRoot or FindMinimum of a sum of squares to get isolated real roots.
Posted 9 years ago
 Thanks Sir ,Your suggestion is really useful and it worked well for my Case.Once again Thanks a lot
Posted 9 years ago
 I am not able to replicate the problem, at least in Mathematica 10.0.2. exp1 = ComplexExpand[ Im[(1 + I)/(2 + 3 I - bb) + (1 + I)/(2 + 3 I - cc)] + Im[(1 + I)/(2 + 3 I - dd)]] - 3.5; exp2 = ComplexExpand[ Im[(2 + 2 I)/(3 + 4 I - bb) + (2 + 2 I)/(3 + 4 I - cc)] + Im[(2 + 2 I)/(3 + 4 I - dd)]] - 0.75; exp3 = ComplexExpand[ Im[(3 + 3 I)/(5 + 7 I - bb) + (3 + 3 I)/(5 + 7 I - cc)] + Im[(3 + 3 I)/(5 + 7 I - dd)]] - 0.75; eq5s = {exp1, exp2, exp3}; varr2 = {bb, cc, dd}; Timing[solns = NSolve[eq5s, varr2];] (* Out= {2.727674, Null} *) In:= Length[solns] (* Out= 48 *) Earlier versions used a different mathod and may be slower. One thing that works in version 9 is to clear denominators. polys = Numerator[Together[eq5s]] Now NSolve[polys, varr2] will be quite fast.
Posted 9 years ago
 It looks like there are too many solutions for NSolve to enumerate. Possibly reformulate the problem using FindRoot. You then have to provide rough estimates for the 3 vector solutions.