<div dir="ltr">It looks correct to me (without knowing what the second objective is). SYMPHONY converts all problems to minimization internally, so the negative objective values are just because we don't check whether the problem was maximization and negate the objective values if it is. This should be easy to change. You can file a ticket and I'll try to get to it.<br>
<br>Ted<br></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Sun, Sep 15, 2013 at 12:39 PM, Papis Wongchaisuwat <span dir="ltr"><<a href="mailto:papis_31@hotmail.com" target="_blank">papis_31@hotmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div><div dir="ltr">Thank you for a reply.<div>I tried to start from simple problem that I found in presentation online.</div><div><div>vmax [8x1, x2]</div><div>s.t. 7x1 + x2 <= 56</div><div>28x1 + 9x2 <= 252</div>
<div>3x1 + 7x2 <=105</div><div>x1, x2 >=0</div><div><br></div><div>In bicriteria.c, I use</div><div><div class="im"><div>#include "symphony.h"</div><div><br></div><div>int main(int argc, char **argv)</div>
<div>{</div><div><br></div><div> sym_environment *env = sym_open_environment();</div><div> sym_parse_command_line(env, argc, argv);</div><div> sym_load_problem(env);</div><div><br></div></div><div> sym_set_obj2_coeff(env, 1, 1);</div>
<div><br></div><div> sym_mc_solve(env);</div><div><br></div><div> sym_close_environment(env);</div><div><br></div><div> return(0);</div><div><br></div><div>}</div></div><div><br></div><div>my lp file :</div><div><p>
Maximize <u></u><u></u></p>
<p><span style="font-family:"Courier New"">obj: 8 var_1 + var_2<u></u><u></u></span></p>
<p><span style="font-family:"Courier New""> </span></p>
<p><span style="font-family:"Courier New"">Subject to <u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;line-height:107%;font-family:"Courier New""> C1: 7 var_1 + var_2 <=
56<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;line-height:107%;font-family:"Courier New"">C2: 28 var_1 + 9 var_2 <= 252<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;line-height:107%;font-family:"Courier New"">C3: 3 var_1+ 7 var_2 <= 105<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;line-height:107%;font-family:"Courier New"">Bound<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;line-height:107%;font-family:"Courier New"">var_1>=0<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;line-height:107%;font-family:"Courier New"">var_2>=0<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:10.5pt;line-height:107%;font-family:"Courier New"">Integer</span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;line-height:107%;font-family:"Courier New"">var_1</span></p><p class="MsoNormal"><span style="font-size:10.5pt;line-height:107%;font-family:"Courier New"">var_2</span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;line-height:107%;font-family:"Courier New"">End <u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:10.5pt;line-height:107%;font-family:"Courier New""><br>
</span></p><p class="MsoNormal"><span style="font-size:10.5pt;line-height:107%;font-family:"Courier New"">I got incorrect results. </span></p><p class="MsoNormal"><span style="font-size:10.5pt;line-height:107%;font-family:"Courier New"">This is what I got</span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;line-height:107%;font-family:"Courier New"">First Objective: -64.000 Second Objective: 0.000 Range: 0.468750-1.000000</span></p></div><div><span style="font-family:'Courier New';font-size:14px;line-height:14px">First Objective: -47.000 Second Objective: -15.000 Range: 0.000000-0.468750</span></div>
<div><span style="font-family:'Courier New';font-size:14px;line-height:14px"><br></span></div><div><font face="Courier New"><span style="font-size:14px;line-height:14px">What did I do wrong?</span></font></div><div>
<font face="Courier New"><span style="font-size:14px;line-height:14px"><br></span></font></div><div><font face="Courier New"><span style="font-size:14px;line-height:14px">Thank you,</span></font></div><div><font face="Courier New"><span style="font-size:14px;line-height:14px">Papis</span></font></div>
<div><span style="font-family:'Courier New';font-size:14px;line-height:14px"><br></span></div><div><span style="font-family:'Courier New';font-size:14px;line-height:14px"><br></span></div><br><div><hr>From: ted@Lehigh.EDU<br>
Date: Sun, 15 Sep 2013 12:27:26 -0400<div class="im"><br>Subject: Re: [Symphony] biobjective problems<br></div>To: <a href="mailto:papis_31@hotmail.com" target="_blank">papis_31@hotmail.com</a><br>CC: <a href="mailto:hennebry@web.cs.ndsu.nodak.edu" target="_blank">hennebry@web.cs.ndsu.nodak.edu</a>; <a href="mailto:symphony@list.coin-or.org" target="_blank">symphony@list.coin-or.org</a><div>
<div class="h5"><br><br><div dir="ltr"><div><div><div>sym_set_obj2_coeff(env, i, j) sets the objective function coefficient of variable "i" to value "j" in the second objective, as documented here:<br>
<br><a href="http://www.coin-or.org/SYMPHONY/man-5.5/node176.html" target="_blank">http://www.coin-or.org/SYMPHONY/man-5.5/node176.html</a><br>
<br></div>At the moment, setting the objective coefficients one by one is the only way to specify a second objective through the API. Of course, you can also just directly set the objective function in SYMPHONY's internal representation of the instance.<br>
<br>I have plans to improve this and to add the ability to specify two objectives through a modeling language, such as GMPL, but I haven't gotten to it yet.<br><br></div>Cheers,<br><br></div>Ted<br></div><div>
<br><br><div>On Sat, Sep 14, 2013 at 10:58 PM, Papis Wongchaisuwat <span dir="ltr"><<a href="mailto:papis_31@hotmail.com" target="_blank">papis_31@hotmail.com</a>></span> wrote:<br><blockquote style="border-left:1px #ccc solid;padding-left:1ex">
<div><div dir="ltr"><div style="line-height:21px;color:rgb(68,68,68);font-size:15px">I found bicriteria.c file in Examples. I tried running with the data set and I got several solutions as I am supposed to get. </div><div style="line-height:21px;color:rgb(68,68,68);font-size:15px">
However, I am not sure whether I got a correct result.</div><div style="line-height:21px;color:rgb(68,68,68);font-size:15px">These are some parts of bicriteria.c file</div><div style="line-height:21px;color:rgb(68,68,68);font-size:15px">
<div>#include "symphony.h"</div><div><br></div><div>int main(int argc, char **argv)</div><div>{</div><div><br></div><div> sym_environment *env = sym_open_environment();</div><div> sym_parse_command_line(env, argc, argv);</div>
<div> sym_load_problem(env);</div><div><br></div><div> sym_set_obj2_coeff(env, 1, -1);</div><div><br></div><div> sym_mc_solve(env);</div><div><br></div><div> sym_close_environment(env);</div><div><br></div><div> return(0);</div>
<div><br></div><div>}</div><div><br></div><div>#endif</div></div><div style="line-height:21px;color:rgb(68,68,68);font-size:15px"><br></div><div style="line-height:21px;color:rgb(68,68,68);font-size:15px">Does anyone know what <span style="line-height:22px;font-size:12pt">sym_set_obj2_coeff(env, 1, -1) means? When should I use 1 or -1?</span></div>
<div style="color:rgb(68,68,68)"><span style="line-height:22px">My sample data is a minimization problem.</span></div><div style="color:rgb(68,68,68)"><span style="line-height:22px"><br></span></div><div style="color:rgb(68,68,68)">
<span style="line-height:22px">Thank you,</span></div><div style="color:rgb(68,68,68)"><span style="line-height:22px">Papis</span></div><br><div>> Date: Fri, 13 Sep 2013 23:29:29 -0500<div><br>> From: <a href="mailto:hennebry@web.cs.ndsu.nodak.edu" target="_blank">hennebry@web.cs.ndsu.nodak.edu</a><br>
> To: <a href="mailto:papis_31@hotmail.com" target="_blank">papis_31@hotmail.com</a><br>> CC: <a href="mailto:symphony@list.coin-or.org" target="_blank">symphony@list.coin-or.org</a><br>> Subject: RE: [Symphony] biobjective problems<br>
> <br></div><div>> On Sat, 14 Sep 2013, Papis Wongchaisuwat wrote:<br>> <br>> > I would like to run bi-objective Set cover and Set pack problems. Attached files are some examples that I want to run. MCKP and these problems are quite different. I don't know how to apply MCKP or either use any other ways to run these problems.<br>
> <br>> From reading the manual,<br>> I gather one can call sym_explicit_load_problem( ... )<br>> and follow it by calling sym_mc_solve( ... ) .<br>> Is there a reason that you cannot do that?<br>> <br>
> -- <br>
> Michael <a href="mailto:hennebry@web.cs.ndsu.NoDak.edu" target="_blank">hennebry@web.cs.ndsu.NoDak.edu</a><br>> "On Monday, I'm gonna have to tell my kindergarten class,<br>> whom I teach not to run with scissors,<br>
> that my fiance ran me through with a broadsword." -- Lily<br></div></div> </div></div>
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<br></blockquote></div><br><br clear="all"><br>-- <br>Dr. Ted Ralphs<br>Associate Professor, Lehigh University<br><a href="tel:%28610%29%20628-1280" value="+16106281280" target="_blank">(610) 628-1280</a><br>ted 'at' lehigh 'dot' edu<br>
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</blockquote></div><br><br clear="all"><br>-- <br>Dr. Ted Ralphs<br>Associate Professor, Lehigh University<br>(610) 628-1280<br>ted 'at' lehigh 'dot' edu<br><a href="http://coral.ie.lehigh.edu/~ted" target="_blank">coral.ie.lehigh.edu/~ted</a><br>
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