jeplus.org forums
Algorithm is not constraining - Printable Version

+- jeplus.org forums (http://jeplus.org/mybb)
+-- Forum: Building simulation tools (http://jeplus.org/mybb/forumdisplay.php?fid=1)
+--- Forum: jEPlus+EA (http://jeplus.org/mybb/forumdisplay.php?fid=3)
+--- Thread: Algorithm is not constraining (/showthread.php?tid=434)



Algorithm is not constraining - JonathanKocher - 07-15-2017

Hello,
I am trying to find the optimal first cost for a net zero energy building. I programmed the constraints and objective as shown below. When I run jEplus+EA, it keeps switching the best solution so that sometimes it is above the constraint limits for energy to be above zero, thus not a net zero energy building. I have a feeling this has to do with the weighting, but I am not sure. See attached picture for an example of the scatter plot. Any ideas on why the optimal solution isn't falling withing the constraints?


   "constraints" : [
   {
       "identifier" : "s1",
       "formula" : "v3",
       "caption" : "Comfort Hours",
       "scaling" : true,
       "lb" : "0",
       "ub" : "300",
       "min" : "-10",
       "max" : "500",
       "weight" : "1.0"
    },
    {
       "identifier" : "s2",
       "formula" : "c0",
       "caption" : "Electricity [kBTU]",
       "scaling" : true,
       "lb" : "-15000",
       "ub" : "0",
       "min" : "-30000",
       "max" : "0",
       "weight" : "5.0"
    }
],
"objectives" : [
   {
       "identifier" : "t1",
       "formula" : "v0",
       "caption" : "Total Construction Cost [$/ft2]",
       "scaling" : true,
       "min" : "100",
       "max" : "500",
       "weight" : "1.0"
   }


RE: Algorithm is not constraining - JonathanKocher - 07-16-2017

I rewrote the .rvx file to have the energy and construction both be objectives and the algorithm found the optimal solution (the cheapest zero energy solution on the pareto front) much faster. Not sure why constraining the energy was not effective, but I will go with this double objective strategy moving forward. See updated rvs below:
"constraints" : [
{
"identifier" : "s1",
"formula" : "v3",
"caption" : "Comfort Hours",
"scaling" : true,
"lb" : "0",
"ub" : "300",
"min" : "-10",
"max" : "500",
"weight" : "1.0"
}
],
"objectives" : [
{
"identifier" : "t1",
"formula" : "v0",
"caption" : "Total Construction Cost [$/ft2]",
"scaling" : false,
"min" : "100",
"max" : "500",
"weight" : "1.0"
},
{
"identifier" : "t2",
"formula" : "c0",
"caption" : "Total Electricity [kBTU]",
"scaling" : false,
"min" : "-50000",
"max" : "500000",
"weight" : "1.0"
}