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Hi,<br>
<br>
<blockquote
cite="mid:CA+Kja=Mpi+NN0ica=2CzEFDDcDM=0XxDmS3ct-unOo47NE=vEg@mail.gmail.com"
type="cite"><br>
Does anybody know what the following messages mean:<br>
<br>
<br>
In iteration 1766, 1 Slack too small, adjusting variable bound<br>
In iteration 1937, 1 Slack too small, adjusting variable bound<br>
</blockquote>
<br>
This message means that a slack variable (for a variable bound or an
inequality constraint) has become very small, too small within
machine precision, and to make sure that the interior point
algorithm can continue with a non-zero slack (and the logarithm of
this slack variable can still be computed), Ipopt internally makes a
small modification of the problem statement, relaxing the
corresponding bound a little bit.<br>
<br>
<blockquote
cite="mid:CA+Kja=Mpi+NN0ica=2CzEFDDcDM=0XxDmS3ct-unOo47NE=vEg@mail.gmail.com"
type="cite">
MA27BD returned iflag=-4 and requires more memory.<br>
Increase liw from 363145 to 3631450 and la from 1139815 to
11411860 and factorize again.<br>
</blockquote>
<br>
This means that the linear system that is solved in every iteration
is becoming ill-conditioned and the linear solver MA27 produces more
fill-in, and therefore require more memory. In your case, it is
more memory than you have available on your machine. You might be
able to go past this barrier by choosing a smaller number for the
ma27_meminc_factor option which determines by how much the memory
allocation should be increased when MA27 runs out of memory (default
is 10, so try 2 or so).<br>
<br>
Andreas<br>
<br>
<blockquote
cite="mid:CA+Kja=Mpi+NN0ica=2CzEFDDcDM=0XxDmS3ct-unOo47NE=vEg@mail.gmail.com"
type="cite">
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<br>
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