"Steven Lord" <Steven_Lord@mathworks.com> wrote in message <firstname.lastname@example.org>... > > "Prabodh " <email@example.com> wrote in message > news:firstname.lastname@example.org... > > Hi, > > I am trying to do least square fit. I have looked at the examples in the > > Matlab official web site that may be somewhat related to my problem. I > > found one that may be useful to me and wrote it exactly as it was shown in > > the Matlab official web site. I have pasted it below: - > > function F = trial(x,xdata) > > F = x(1)*exp(x(2)*xdata); > > I suspect that you're trying to call LSQCURVEFIT with @trial as the first > input INSIDE THE TRIAL FUNCTION itself. That is not correct. Your trial.m > file should contain exactly the above two lines, that's it. > > > x =[1 0.2 3 4 5 6 7 8 9 10]; % (This part is not given in the web site. I > > added it % %after I got the error message. This did not fix the problem. > > Then I tried giving this % data different name, but it still did not fix > > the problem.) > > The line above is unnecessary. Place the four lines below in a separate > file: > > > xdata =[0.9 1.5 13.8 19.8 24.1 28.2 35.2 60.3 74.6 81.3]; > > ydata =[455.2 428.6 124.1 67.3 43.2 28.1 13.1 -0.4 -1.3 -1.5]; > > x0 = [100; -1] % Starting guess > > [x,resnorm] = lsqcurvefit(@trial,x0,xdata,ydata); > > To execute this example, execute the name of the file containing this code, > not the trial function. > > -- > Steve Lord > email@example.com > To contact Technical Support use the Contact Us link on > http://www.mathworks.com
Thank you very much Steve Lord. I think that's the problem. I wrote everything in the same file called trial.m. It worked when I created two separate files. I trial.m I wrote only the first two sentences and in another file I wrote the rest four sentences and it worked. Thank you very much. Prabodh.