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Dear Shen,<br>
<br>
don't worry, nothing went wrong, this is similar to the behavior I
observed.<br>
<br>
Note that the VRP example is just a very basic example for how a
pricer can be implemented. It does not focus on providing good
performance since this would complicate the code. If you want to
implement a branch-and-price code, I would always recommend to look
at the binpacking example or the coloring application. These two
provide a better overview of what is normally needed for
branch-and-price code, including problem data and a dedicated
branching rule.<br>
<br>
Best regards,<br>
Gerald<br>
<br>
<div class="moz-cite-prefix">On 30.01.19 11:51, Shen Li wrote:<br>
</div>
<blockquote type="cite"
cite="mid:41B2F12B-7A65-4698-80A5-9D758CBB4D06@googlemail.com">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
Dear SCIP mailing list
<div class=""><br class="">
</div>
<div class="">I just compiled the VRP example of the SCIP package,
and I obtained the following output for eil22.vrp (part of the
SCIP/VRP data files):</div>
<div class=""><br class="">
</div>
<div class="">
<div class="">(…)</div>
<div class="" style="margin: 0px; font-stretch: normal;
font-size: 11px; line-height: normal; font-family: Menlo;"><span
class="" style="font-variant-ligatures:
no-common-ligatures;"> time | node | left |LP iter|LP
it/n| mem |mdpt |frac |vars |cons |cols |rows |cuts
|confs|strbr| dualbound | primalbound | gap </span></div>
</div>
<div class="">(…)</div>
<div class="">
<div class="" style="margin: 0px; font-stretch: normal;
font-size: 11px; line-height: normal; font-family: Menlo;"><span
class="" style="font-variant-ligatures:
no-common-ligatures;"> 428s| 300 | 15 |554079 |1689.8
| 256M| 20 | 29 | 37k| 273 | 13k| 273 | 2 | 0 | 421
| 3.687105e+02 | 3.750000e+02 | 1.71%</span></div>
</div>
<div class=""><br class="">
</div>
<div class=""><span class="" style="font-variant-ligatures:
no-common-ligatures;">
<div class="" style="margin: 0px; font-stretch: normal;
font-size: 11px; line-height: normal; font-family: Menlo;"><span
class="" style="font-variant-ligatures:
no-common-ligatures;">SCIP Status : problem is
solved [optimal solution found]</span></div>
<div class="" style="margin: 0px; font-stretch: normal;
font-size: 11px; line-height: normal; font-family: Menlo;"><span
class="" style="font-variant-ligatures:
no-common-ligatures;">Solving Time (sec) : 476.24</span></div>
<div class="" style="margin: 0px; font-stretch: normal;
font-size: 11px; line-height: normal; font-family: Menlo;"><span
class="" style="font-variant-ligatures:
no-common-ligatures;">Solving Nodes : 359</span></div>
<div class="" style="margin: 0px; font-stretch: normal;
font-size: 11px; line-height: normal; font-family: Menlo;"><span
class="" style="font-variant-ligatures:
no-common-ligatures;">Primal Bound :
+3.75000000000000e+02 (23 solutions)</span></div>
<div class="" style="margin: 0px; font-stretch: normal;
font-size: 11px; line-height: normal; font-family: Menlo;"><span
class="" style="font-variant-ligatures:
no-common-ligatures;">Dual Bound :
+3.75000000000000e+02</span></div>
<div class="" style="margin: 0px; font-stretch: normal;
font-size: 11px; line-height: normal; font-family: Menlo;"><span
class="" style="font-variant-ligatures:
no-common-ligatures;">Gap : 0.00 %</span></div>
<div class="" style="margin: 0px; font-stretch: normal;
font-size: 11px; line-height: normal; font-family: Menlo;"><span
class="" style="font-variant-ligatures:
no-common-ligatures;">SCIP Status : problem is
solved [optimal solution found]</span></div>
<div class="" style="margin: 0px; font-stretch: normal;
font-size: 11px; line-height: normal; font-family: Menlo;"><span
class="" style="font-variant-ligatures:
no-common-ligatures;">Total Time : 476.24</span></div>
<div class="" style="margin: 0px; font-stretch: normal;
font-size: 11px; line-height: normal; font-family: Menlo;"><span
class="" style="font-variant-ligatures:
no-common-ligatures;"> solving : 476.24</span></div>
<div class="" style="margin: 0px; font-stretch: normal;
font-size: 11px; line-height: normal; font-family: Menlo;"><span
class="" style="font-variant-ligatures:
no-common-ligatures;"> presolving : 0.00
(included in solving)</span></div>
<div class="" style="margin: 0px; font-stretch: normal;
font-size: 11px; line-height: normal; font-family: Menlo;"><span
class="" style="font-variant-ligatures:
no-common-ligatures;"> reading : 0.00</span></div>
<div class="" style="margin: 0px; font-stretch: normal;
font-size: 11px; line-height: normal; font-family: Menlo;"><span
class="" style="font-variant-ligatures:
no-common-ligatures;"> copying : 0.06 (3
#copies) (minimal 0.02, maximal 0.03, average 0.02)</span></div>
<div class="">(…)</div>
<div class=""><br class="">
</div>
<div class="">I found it surprising that it took 428 seconds
to solve this instance, which is typically solved within
fractions of a second. Is this is similar to the behaviour
you have observed? If not, any pointers to where I may have
gone wrong would be greatly appreciated!</div>
<div class=""><br class="">
</div>
<div class="">Many thanks</div>
<div class=""><br class="">
</div>
<div class="">Shen</div>
</span></div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
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</blockquote>
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