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Re: lsqcurvefit with matrix "xdata"
Posted:
May 10, 2013 8:07 AM


On 5/9/2013 3:54 PM, Jonathan wrote: > I am trying to use lsqcurvefit to find a single parameter estimate > with two x values per predicted y, but the result is always "Function > value and YDATA sizes are incommensurate." Previously, when using a > similar function with only one value for x data per predicted y the > lsqcurvefit worked fine. The function that I am using returns the > correct results, a single y value, when I supply a parameter. I have > tried tinkering with the function thinking I messed it up some how, > but to no avail. > > function = @(k,x) (100./(1+k.*x(1))) + (100./(1+k.*x(2))) > x0 = .01 > ydata = <36,1> Double > xdata = <36,2> Double > > I am trying to determine if the summation of two hyperbolas is enough > to explain the ydata or if I need to consider another model. > > The documentation and help that I can find suggests that using a two > variable function for lsqcurvefit is possible, but for the life of me > I can not figure it out (where I screwed up). Thanks for any help. > > Jon
Did you try to run the documentation example http://www.mathworks.com/help/optim/ug/nonlinearcurvefittingwithlsqcurvefit.html Does that example run for you?
Alan Weiss MATLAB mathematical toolbox documentation



