[Ipopt] Warning: Cutting back alpha due to evaluation error

Andreas Waechter andreasw at watson.ibm.com
Mon Aug 9 08:21:35 EDT 2010

Hi Mehmet,

It means that either an evaluation method returned false, or that a Nan 
(Not a Number) or Inf (Infinity) floating point values appeared in the 
function or gradient values.  This can happen if you take the log of a 
negative number or divide by zero.



On Sat, 7 Aug 2010, Mehmet Saglam wrote:

> Hello,
> If we get the following warning in iterations, "Warning: Cutting back alpha
> due to evaluation error," does that necessarily mean that our
> implementations is wrong? If not, why do we get such a warning message?
> Best,
> Mehmet

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