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<div class="moz-cite-prefix">Fixed hopefully - stable and trunk.<br>
<br>
The original model is not well scaled - one element was 2.1e14 and
even after preprocessing the problem had to be solved applying
scaling factors. The small fast branch and bound is deliberately
a bit forgiving on this. When the code thinks it has got a
solution it double checks. In this case it did that and threw
that solution out - but it had left some variables fixed when they
should not have been.<br>
<br>
John Forrest<br>
<br>
On 28/12/17 18:30, John Forrest wrote:<br>
</div>
<blockquote type="cite"
cite="mid:217f2bdc-5771-7d0c-1d32-bd73254d3717@fastercoin.com">
<div class="moz-cite-prefix">Ryan,<br>
<br>
Bug in Cbc. My first try gave correct result, but I managed to
get error. For small problems, Cbc will do a simpler faster
branch and bound on a portion of the tree. This is returning
infeasible - I will look into it.<br>
<br>
If you add -depth -100 (which means only go into this simpler
version at depth 100) then all looked fine.<br>
<br>
John Forrest<br>
On 27/12/17 18:37, Rhavar wrote:<br>
</div>
<blockquote type="cite"
cite="mid:wEJdFCqH7dWFQIUWSgGjrSlOLnuoiz1_mTpgEQhuUhqiobGTkqeoVirLLCouhjV2D-CqKcsJZtEuHLii2_tZ7ZY_1-vv7-hy-1B5eMsYuzE=@protonmail.com">
<div>I have a problem:<br>
</div>
<div><a
href="https://urldefense.proofpoint.com/v2/url?u=https-3A__gist.github.com_RHavar_dfb9de631363ecb9e1c326fff5ebd09b&d=DwMDaQ&c=Ngd-ta5yRYsqeUsEDgxhcqsYYY1Xs5ogLxWPA_2Wlc4&r=js2M0T-3OIMIVDvokcKjokJbk0F8QOCd0mT4FsVFE88&m=S4VZrfTJ9vrNsPyEyqDoTZUqb0eG9rdZ8l7-jr8EA9Y&s=dWErV9QjwaNhpQZZkV1ZmdJ_Ofpqgb80lh0-5ORAiSU&e="
moz-do-not-send="true">https://gist.github.com/RHavar/dfb9de631363ecb9e1c326fff5ebd09b</a><br>
</div>
<div><br>
</div>
<div>(lp file and solution file attached)<br>
</div>
<div><br>
</div>
<div>In the solution it says: "Optimal - objective value" but I
think I have found a superior solution by hand:<br>
</div>
<div><br>
</div>
<div><span class="s1"><span class="Apple-converted-space"> </span>o6
= 1</span><br>
</div>
<div>i22 = 1<br>
</div>
<div><br>
</div>
<div>Which gives a better objective (<span class="s1">70 instead
of </span>825)<br>
</div>
<div><br>
</div>
<div>--<br>
</div>
<div><br>
</div>
<div>So I guess my question is, does "Optimal - objective
value" mean that it's guaranteed to be the optimal solution?
Or am I doing something wrong? Or is there a bug in cbc? <br>
</div>
<div><br>
</div>
<div><br>
</div>
<div class="protonmail_signature_block">
<div class="protonmail_signature_block-user">
<div>-Ryan<br>
</div>
</div>
<div class="protonmail_signature_block-proton
protonmail_signature_block-empty"><br>
</div>
</div>
<div><br>
</div>
<br>
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<pre wrap="">_______________________________________________
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</pre>
</blockquote>
<p><br>
</p>
<br>
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<br>
<pre wrap="">_______________________________________________
Cbc mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Cbc@list.coin-or.org">Cbc@list.coin-or.org</a>
<a class="moz-txt-link-freetext" href="https://urldefense.proofpoint.com/v2/url?u=https-3A__list.coin-2Dor.org_mailman_listinfo_cbc&d=DwICAg&c=Ngd-ta5yRYsqeUsEDgxhcqsYYY1Xs5ogLxWPA_2Wlc4&r=js2M0T-3OIMIVDvokcKjokJbk0F8QOCd0mT4FsVFE88&m=S4VZrfTJ9vrNsPyEyqDoTZUqb0eG9rdZ8l7-jr8EA9Y&s=SVcz-BvCf0RgvZrRQQxyV89AGoSkVGhfQhv4tx1JKV4&e=">https://urldefense.proofpoint.com/v2/url?u=https-3A__list.coin-2Dor.org_mailman_listinfo_cbc&d=DwICAg&c=Ngd-ta5yRYsqeUsEDgxhcqsYYY1Xs5ogLxWPA_2Wlc4&r=js2M0T-3OIMIVDvokcKjokJbk0F8QOCd0mT4FsVFE88&m=S4VZrfTJ9vrNsPyEyqDoTZUqb0eG9rdZ8l7-jr8EA9Y&s=SVcz-BvCf0RgvZrRQQxyV89AGoSkVGhfQhv4tx1JKV4&e=</a>
</pre>
</blockquote>
<p><br>
</p>
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