http://www.mathworks.com/matlabcentral/newsreader/view_thread/255229 MATLAB Central Newsreader - Obtaining real answers with lsqcurvefit Feed for thread: Obtaining real answers with lsqcurvefit en-us &copy;1994-2012 by MathWorks, Inc. webmaster@mathworks.com MATLAB Central Newsreader http://blogs.law.harvard.edu/tech/rss 60 MathWorks http://www.mathworks.com/images/membrane_icon.gif Thu, 02 Jul 2009 23:00:03 -0400 Obtaining real answers with lsqcurvefit http://www.mathworks.com/matlabcentral/newsreader/view_thread/255229#662401 geg1633 Mona Hello all,<br> <br> I'm fit a dataset to F=A.x^2+log(Bx+C). My lower bounds for A, B and C are Zero, and my upper bounds vary between 10 and .1. <br> <br> After a few iterations, lsqcurvefit outputs imaginary estimates for A,B, and C. <br> <br> My question is:<br> 1- How can I force it to output only real values?<br> 2-How can I impose 0&lt; Bx+C &lt;.1?<br> <br> Thanks!