mean iou debug jolibrain#2

Author: fantes

src/supervisedoutputconnector.h

@@ -673,14 +673,22 @@ namespace dd
 		  double accc = c_sum / c_total_targ;
 		  mean_acc[c] += accc;
 		  mean_acc_bs[c]++;
-		}
 
-	      // mean intersection over union
+        }
+
+           // mean intersection over union
 	      double c_false_neg = static_cast<double>((ddiffc.array() == -2-c).count());
-	      double c_false_pos = static_cast<double>((ddiffc.array() == c+1).count()); 
-	      double iou = (c_sum==0) ? 0: c_sum / (c_false_pos + c_sum + c_false_neg);
+	      double c_false_pos = static_cast<double>((ddiffc.array() == c+1).count());
+          // below corner case where nothing is to predict : put correct to zero
+          // but do not devide by zero
+          double iou =  (c_sum == 0)? 0 : c_sum / (c_false_pos + c_sum + c_false_neg);
 	      mean_iou[c] += iou;
-	      mean_iou_bs[c]++;
+          // ... and divide one time less when normalizing by batch size
+          if (c_total_targ !=0)
+            mean_iou_bs[c]++;
+          // another possible waywould be to put artificially iou to one if nothing is to be
+          // predicted for class c
+
 	    }
 	}
       int c_nclasses = 0;
@@ -696,6 +704,7 @@ namespace dd
 	  meaniou += mean_iou[c];
 	}
       clacc = mean_acc;
+      // corner case where prediction is wrong
       if (c_nclasses > 0) {
         meanacc /= static_cast<double>(c_nclasses);
         meaniou /= static_cast<double>(c_nclasses);

tests/ut-conn.cc

@@ -56,21 +56,35 @@ TEST(outputconn,acc)
 
 TEST(outputconn,acc_v)
 {
-  std::vector<double> targets = {0.0, 0.0, 1.0, 1.0};
-  std::vector<double> pred1 = {0.0,1.0,1.0,1.0};
-  std::vector<std::vector<double>> preds = { pred1 };
   APIData res_ad;
-  res_ad.add("batch_size",static_cast<int>(1));
+  res_ad.add("batch_size",static_cast<int>(2));
+  res_ad.add("nclasses",static_cast<int>(2));
+
   APIData bad;
+  std::vector<double> targets = {0.0, 1.0 };
+  std::vector<double> pred1 = {0.0, 1.0};
   bad.add("pred",pred1);
   bad.add("target",targets);
   std::vector<APIData> vad = {bad};
   res_ad.add(std::to_string(0),vad);
+
+
+  APIData bad2;
+  std::vector<double> targets2 = {0.0, 0.0};
+  std::vector<double> pred2 = {0.0, 1.0};
+  bad2.add("pred",pred2);
+  bad2.add("target",targets2);
+  std::vector<APIData> vad2 = {bad2};
+  res_ad.add(std::to_string(1),vad2);
+
+
+
   SupervisedOutput so;
   double meanacc = 0.0, meaniou = 0.0;
   std::vector<double> clacc;
   double acc = so.acc_v(res_ad,meanacc,meaniou,clacc);
   ASSERT_EQ(0.75,acc);
+  ASSERT_EQ(0.875,meaniou)
 }
 
 TEST(outputconn,acck)