1 files changed, 63 insertions, 0 deletions
diff --git a/sleepingcelldetector/src/main/java/org/onap/rapp/sleepingcelldetector/service/scd/CalculationUtil.java b/sleepingcelldetector/src/main/java/org/onap/rapp/sleepingcelldetector/service/scd/CalculationUtil.java
new file mode 100644
index 0000000..95aecae
--- /dev/null
+++ b/sleepingcelldetector/src/main/java/org/onap/rapp/sleepingcelldetector/service/scd/CalculationUtil.java
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2021 Samsung Electronics
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package org.onap.rapp.sleepingcelldetector.service.scd;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import java.util.List;
+import java.util.Objects;
+import java.util.OptionalDouble;
+import java.util.stream.Collectors;
+
+public class CalculationUtil {
+
+    private static final Logger logger = LoggerFactory.getLogger(CalculationUtil .class);
+    public static final int MIN_PERCENTAGE_OF_DATA_FILLING = 30;
+
+    private CalculationUtil(){
+    }
+
+    public static Integer calculateAverage(List<Integer> values){
+        OptionalDouble average = values.stream().mapToDouble(l -> l).average();
+
+        if (average.isPresent()) {
+            return (int) average.getAsDouble();
+        } else {
+            throw new ArithmeticException("Can't calculate average");
+        }
+    }
+
+    public static List<Integer> fillGaps(List<Integer> values){
+        verifyDataFilling(values);
+        Integer average = calculateAverage(values.stream().filter(Objects::nonNull).collect(Collectors.toList()));
+
+        for (int i=0; i<values.size(); i++){
+            if(values.get(i) == null){
+                values.set(i, average);
+            }
+        }
+        return values;
+    }
+
+    public static void verifyDataFilling(List<Integer> values) {
+        double measurementsNumber = values.stream().filter(Objects::nonNull).count();
+        double listSize = values.size();
+        double dataFillingPercentage = measurementsNumber/listSize * 100;
+        if (dataFillingPercentage < MIN_PERCENTAGE_OF_DATA_FILLING){
+            logger.warn("Not enough data to make prediction, must be at least 30%; Data filling: {}%", dataFillingPercentage);
+            throw new ArithmeticException("Not enough performance data for prediction, data filling: " + dataFillingPercentage + "%");
+        }
+    }
+
+}