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I would advise against using the min function, as this will create a discontinuity in your objective function. You could try other approaches, such as rescaling your data etc, but hard to help without seeing the code.
<div>Steve<br>
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<div>On 2013-03-06, at 11:36 AM, "Fowler, Mark" <<a href="mailto:Mark.Fowler@dfo-mpo.gc.ca">Mark.Fowler@dfo-mpo.gc.ca</a>></div>
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<p dir="LTR"><span lang="en-ca"><font face="Calibri">Hello,</font></span></p>
<p dir="LTR"><span lang="en-ca"><font face="Calibri">I think I’ve hit a precision limit</font></span><span lang="en-ca"><font face="Calibri">, looking for a solution along the same sort of lines as posfun</font></span><span lang="en-ca"><font face="Calibri">
or mfexp</font></span><span lang="en-ca"><font face="Calibri">. My program stops (no error message) in a loop</font></span><span lang="en-ca">
<font face="Calibri">when a particular equation attempts to divide 19616.8 by 7.57411e-154.</font></span><span lang="en-ca">
<font face="Calibri">The preceding iteration worked with 21666/5.73085e-132. These are s</font></span><span lang="en-ca"><font face="Calibri">illy</font></span><span lang="en-ca">
<font face="Calibri">starting</font></span><span lang="en-ca"> <font face="Calibri">
estimates of a value which will get</font></span><span lang="en-ca"><font face="Calibri"> reasonable with a little fitting, I just</font></span><span lang="en-ca">
<font face="Calibri">want</font></span><span lang="en-ca"><font face="Calibri"> to accept</font></span><span lang="en-ca">
<font face="Calibri">a maximal result instead of bombing.</font></span><span lang="en-ca"><font face="Calibri"></font></span><span lang="en-ca">
<font face="Calibri">In this case I can just use a min function on the denominator</font></span><span lang="en-ca"><font face="Calibri">, but wonder if there isn’t a conventional approach for this situation</font></span><span lang="en-ca"><font face="Calibri">,
say defining a minimum number threshold</font></span><span lang="en-ca"><font face="Calibri">.</font></span><span lang="en-ca"></span></p>
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<p dir="LTR"><span lang="en-ca"></span><span lang="en-ca"></span><span lang="en-ca"></span><span lang="en-ca"><font size="2" face="Arial">Mark Fowler</font></span></p>
<p dir="LTR"><span lang="en-ca"><font size="2" face="Arial">Population Ecology Division</font></span></p>
<p dir="LTR"><span lang="en-ca"><font size="2" face="Arial">Bedford Inst of Oceanography</font></span></p>
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<p dir="LTR"><span lang="en-ca"><font size="2" face="Arial">Dartmouth NS Canada</font></span></p>
<p dir="LTR"><span lang="en-ca"></span><span lang="en-ca"></span><span lang="en-ca"></span><span lang="en-ca"><font size="2" face="Arial">B2Y 4A2</font></span></p>
<p dir="LTR"><span lang="en-ca"><font size="2" face="Arial">Tel. (902) 426-3529</font></span></p>
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<p dir="LTR"><span lang="en-ca"><font size="2" face="Arial">Email <a href="mailto:Mark.Fowler@dfo-mpo.gc.ca">
Mark.Fowler@dfo-mpo.gc.ca</a></font></span></p>
<p dir="LTR"><span lang="en-ca"></span><span lang="en-ca"></span><span lang="en-ca"></span><span lang="en-ca"><font size="2" face="Arial">Home Tel. (902) 461-0708</font></span></p>
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