Feature/support grid sampler

CHANGELOG.md

@@ -12,9 +12,10 @@ Please see [here](https://github.com/hrntsm/Tunny/releases) for the data release
 
 - Restore progressbar
 - Support Galapagos genepool input
-- Reflect button
+- Result reflect button
   - This feature reflecting multi objective optimization result to slider & genepool to use input model number.
   - if input multi model number, the first one is reflect and popup notification about this.
+- Support grid sampler
 
 ### Changed
 

Tunny/Solver/OptunaAlgorithm.cs

@@ -64,6 +64,20 @@ public void Solve()
                     case "NSGA-II":
                         sampler = optuna.samplers.NSGAIISampler();
                         break;
+                    case "Grid":
+                        var searchSpace = new Dictionary<string, List<double>>();
+                        for (int i = 0; i < n; i++)
+                        {
+                            var numSpace = new List<double>();
+                            for (int j = 0; j < nTrials; j++)
+                            {
+                                numSpace.Add(Lb[i] + (Ub[i] - Lb[i]) * j / (nTrials - 1));
+                            }
+                            searchSpace.Add(VarNickName[i], numSpace);
+                        }
+                        nTrials = (int)Math.Pow(nTrials, n);
+                        sampler = optuna.samplers.GridSampler(searchSpace);
+                        break;
                     default:
                         sampler = optuna.samplers.TPESampler();
                         break;
@@ -116,7 +130,14 @@ public void Solve()
                         }
                     }
                     trial.set_user_attr("geometry", result.ModelDraco);
-                    study.tell(trial, result.ObjectiveValues.ToArray());
+                    try
+                    {
+                        study.tell(trial, result.ObjectiveValues.ToArray());
+                    }
+                    catch
+                    {
+                        break;
+                    }
                 }
 
                 if (nObjective == 1)

Tunny/UI/OptimizationWindow.cs

@@ -168,9 +168,15 @@ private void OptimizeRunButton_Click(object sender, EventArgs e)
                 optimizeRunButton.Enabled = true;
                 return;
             }
-            else if (objectiveValues.Count > 1 && (samplerComboBox.Text == "CMA-ES" || samplerComboBox.Text == "Random"))
+            else if (objectiveValues.Count > 1
+                     && (samplerComboBox.Text == "CMA-ES" || samplerComboBox.Text == "Random" || samplerComboBox.Text == "Grid"))
             {
-                MessageBox.Show("This sampler does not support multiple objectives optimization.", "Tunny", MessageBoxButtons.OK, MessageBoxIcon.Error);
+                TunnyMessageBox.Show(
+                    "CMA-ES, Random and Grid samplers only support single objective optimization.",
+                    "Tunny",
+                    MessageBoxButtons.OK,
+                    MessageBoxIcon.Error
+                );
                 ghCanvas.EnableUI();
                 optimizeRunButton.Enabled = true;
                 return;