Path: news.mathworks.com!not-for-mail From: "Mamon " <mamoon_hatmal@yahoo.com> Newsgroups: comp.soft-sys.matlab Subject: Re: MATLAB PROBLEM Date: Sun, 5 Sep 2010 23:04:04 +0000 (UTC) Organization: University of Southern California Lines: 23 Message-ID: <i617l4$1g4$1@fred.mathworks.com> References: <i602m1$3v$1@fred.mathworks.com> <i60jak$6ib$1@fred.mathworks.com> <i610m0$9oh$1@fred.mathworks.com> <i613v4$7ff$1@fred.mathworks.com> Reply-To: "Mamon " <mamoon_hatmal@yahoo.com> NNTP-Posting-Host: webapp-03-blr.mathworks.com Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Trace: fred.mathworks.com 1283727844 1540 172.30.248.38 (5 Sep 2010 23:04:04 GMT) X-Complaints-To: news@mathworks.com NNTP-Posting-Date: Sun, 5 Sep 2010 23:04:04 +0000 (UTC) X-Newsreader: MATLAB Central Newsreader 2478768 Xref: news.mathworks.com comp.soft-sys.matlab:667826 "Roger Stafford" <ellieandrogerxyzzy@mindspring.com.invalid> wrote in message <i613v4$7ff$1@fred.mathworks.com>... > "Mamon " <mamoon_hatmal@yahoo.com> wrote in message <i610m0$9oh$1@fred.mathworks.com>... > > Hi Roger, > > finding all the solutions is one of the problems, my main problem now is to use fsolve inside *.m file, I did that (as indicated in the above code) but I always receive an error, so I wonder if you have any idea how to correct the code to make fsolve work in *.m file. > > thank you, > > Ma'mon > - - - - - - - - - - - > I have already indicated to you why you are getting the error. The 'fsolve' function does not like to receive more equations than unknowns. It will continue to do so until you correct this aspect of your problem. > > I have also told you that you will get at most two solutions to the F(1), F(3), F(5) equations and at most two to the F(2), F(4), F(6) equations which makes a total of four possible combinations. Unless the F(7) equation is just right, it will fail for each of these four, which would mean there would be no solutions at all. What makes you believe that F(7) is compatible with the others? > > And finally I have told you there is a way of getting both solutions to a three-spheres intersection problem using straightforward analysis rather than using fsolve in case it gives you only one solution. > > Roger Stafford Hi Roger, I'm sorry because it is my mistake from beginning not to explain that enough. I know the solution for these equations because I'm writing a code now and I'm trying to apply that for known cases first, so I know exactly the solution for that, fsolve is working inside the command window and gives me always a solution (which depends on the intial guess), but I have two problems: 1-make fsolve working inside *.m file. 2-if there is a method (e.g. for loop) that change the initial guess every time so we can have mutiple solutions. the method that you have suggested (straightforward analysis ) is intersting so I will read about it, but is it called "straightforward analysis" analysis . thank you,