The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » Software » comp.soft-sys.matlab

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

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

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]

Posts: 4
Registered: 5/9/13
lsqcurvefit with matrix "xdata"
Posted: May 9, 2013 3:54 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

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.


Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.