
lsqcurvefit with matrix "xdata"
Posted:
May 9, 2013 3:54 PM


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

