<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<meta name="Generator" content="Microsoft Word 14 (filtered medium)">
<style><!--
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";
mso-fareast-language:EN-US;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph
{mso-style-priority:34;
margin-top:0in;
margin-right:0in;
margin-bottom:0in;
margin-left:.5in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";
mso-fareast-language:EN-US;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri","sans-serif";
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
mso-fareast-language:EN-US;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
/* List Definitions */
@list l0
{mso-list-id:1422798947;
mso-list-type:hybrid;
mso-list-template-ids:-1530469072 269025297 269025305 269025307 269025295 269025305 269025307 269025295 269025305 269025307;}
@list l0:level1
{mso-level-text:"%1\)";
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l0:level2
{mso-level-number-format:alpha-lower;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l0:level3
{mso-level-number-format:roman-lower;
mso-level-tab-stop:none;
mso-level-number-position:right;
text-indent:-9.0pt;}
@list l0:level4
{mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l0:level5
{mso-level-number-format:alpha-lower;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l0:level6
{mso-level-number-format:roman-lower;
mso-level-tab-stop:none;
mso-level-number-position:right;
text-indent:-9.0pt;}
@list l0:level7
{mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l0:level8
{mso-level-number-format:alpha-lower;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l0:level9
{mso-level-number-format:roman-lower;
mso-level-tab-stop:none;
mso-level-number-position:right;
text-indent:-9.0pt;}
@list l1
{mso-list-id:1870800448;
mso-list-type:hybrid;
mso-list-template-ids:922004046 269025297 269025305 269025307 269025295 269025305 269025307 269025295 269025305 269025307;}
@list l1:level1
{mso-level-text:"%1\)";
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l1:level2
{mso-level-number-format:alpha-lower;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l1:level3
{mso-level-number-format:roman-lower;
mso-level-tab-stop:none;
mso-level-number-position:right;
text-indent:-9.0pt;}
@list l1:level4
{mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l1:level5
{mso-level-number-format:alpha-lower;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l1:level6
{mso-level-number-format:roman-lower;
mso-level-tab-stop:none;
mso-level-number-position:right;
text-indent:-9.0pt;}
@list l1:level7
{mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l1:level8
{mso-level-number-format:alpha-lower;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l1:level9
{mso-level-number-format:roman-lower;
mso-level-tab-stop:none;
mso-level-number-position:right;
text-indent:-9.0pt;}
ol
{margin-bottom:0in;}
ul
{margin-bottom:0in;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-CA" link="blue" vlink="purple">
<div class="WordSection1">
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA">Hello Dip/Dippy Community,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA">I am new to implementing decomposition algorithms and Dip/Dippy and am trying to figure out how the platform works. I have a couple
of general questions:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA">1) On pg. 15 of http://coral.ie.lehigh.edu/~ted/files/papers/RAMP12.pdf it states “The return value of relaxed solver is a list of
DecompVar objects having negative reduced cost.” This appears to be the case for the cutting_stock.py and bin_pack_decomp_func.py for example, but not the case for facility_location.py nor gap.py. When is it necessary to return a list of dippy.DecompVar
instances, and when does it suffice to return a regular sparse dictionary of variables? Also, why isn’t the reduced cost being returned in gap.py when the dippy.Solve option is: 'doPriceCut': '1'.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA">In cutting_stock.py, the function ‘relaxed_solver’ ends by returning a list containing a dippy.DecompVar instance:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> dv = dippy.DecompVar(var_values, rc - convexDual, 1)<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> return [dv]<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA">In bin_pack_decomp_func.py, the function ‘solve_subproblem’ ends by returning a list containing a dippy.DecompVar instance:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> dv = dippy.DecompVar(var_values, rc - convexDual, waste)<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> return [dv]<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA">In facility_location.py, the function ‘solve_subproblem’ ends by returning a list containing a regular dictionary:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> var_values = dict([(avars[i], 1) for i in solution])<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> var_values[use_vars[loc]] = 1<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> …<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> return [var_values]<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA">In gap.py, the function ‘solve_subproblem’ ends by returning a list containing a regular dictionary:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> var_values = dict([(var[i], 1) for i in solution])<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> …<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> return [var_values]<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA">2) I am confused about the effect of the following dippy.Solve options:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> 'doCut',<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> 'generateCuts',<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> 'generateInitVars',<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> 'doPriceCut',<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> 'CutCGL'<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA">For some context, in facility_location.py the following code exists:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> dippyOpts = {}<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> algo = 'PriceCut'<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> if len(sys.argv) > 1:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> algo = sys.argv[1]<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> if algo == 'PriceCut':<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> dippyOpts['doPriceCut'] = '1'<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> dippyOpts['CutCGL'] = '1'<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> elif algo == 'Price':<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> dippyOpts['doPriceCut'] = '1'<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> dippyOpts['CutCGL'] = '0'<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> else:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"> dippyOpts['doCut'] = '1'<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA">Are the last 3 conditionals how one would specify ‘Branch-and-price-and-cut’, ‘branch-and-price’, and ‘branch-and-cut’ respectively?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA">Would setting just dippyOpts['doCut'] = '0' result in ‘Branch-and-Bound’?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA">3) I have a model built for a real-world application, but it’s not behaving the way I expected it would. There are potentially a number
of things wrong and I would like to discuss it with someone knowledgeable. If one of the devs has time for a quick review, could you reply to this message?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA">Also, I am unable to access the online doxygen documentation at http://www.coin-or.org/Doxygen/Dip/ as listed on the github page. I
am receiving “403 Forbidden You don't have permission to access /Doxygen/Dip/ on this server.” I am not sure if this is on my end or if it’s affecting everyone.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-language:EN-CA">- Mark<o:p></o:p></span></p>
</div>
<DIV><P><HR>
The information contained in this email is intended only for the individual or entity to whom it is addressed. Its contents (including any attachments) may contain confidential and/or privileged information. If you are not an intended recipient, you may not use, disclose, disseminate, copy or print its contents. If you received this email in error, please notify the sender by reply email and delete and destroy the message.<BR>
<BR>
L’information contenue dans ce courriel est destinée exclusivement aux personnes ou aux entités auxquelles le courriel est adressé. Le contenu de ce courriel (y compris toute pièce jointe) peut renfermer de l’information confidentielle et / ou privilégiée. Si ce message ne vous est pas destiné, vous ne pouvez utiliser, divulguer, diffuser, copier ou imprimer son contenu. Si vous avez reçu ce courriel par erreur, veuillez aviser l’expéditeur en lui faisant parvenir une réponse. De plus, veuillez supprimer et détruire le message.
</P></DIV>
</body>
</html>