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Topic: lsqcurvefit with matrix "xdata"
Replies: 7   Last Post: May 11, 2013 9:58 AM

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Jonathan

Posts: 4
Registered: 5/9/13
lsqcurvefit with matrix "xdata"
Posted: May 9, 2013 3:54 PM
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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



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