Finish Completion Linear.

src/ecoparasite/completion/Completion.java

@@ -64,4 +64,61 @@ public class Completion {
         return mean / i;
     }
 
+    public static <T,V extends Number> HashSet<T> completeColumnsLinear(HashSet<T> list, Function<T,V> getX,  Function<T,V> getY, BiConsumer<T,V> setY ){
+
+        double meanX =  calculateMean(list, getX);
+        double meanY =  calculateMean(list, getY);
+
+        double a = calculateLinearA(list,getX,getY,meanX,meanY);
+        double b = calculateLinearB(meanX,meanY,a);
+
+        for(T item : list){
+            if( getY.apply(item) == null && getX.apply(item) != null ){
+                Double value = a * getX.apply(item).doubleValue() + b;
+                setY.accept( item, (V) value );
+            }
+        }
+
+        return list;
+    }
+
+    /**
+     * Permet de calculer le coefficient A de notre regression linéaire.
+     * @param list
+     * @param getX
+     * @param getY
+     * @param meanX
+     * @param meanY
+     * @return
+     * @param <T>
+     * @param <V>
+     */
+    public static <T,V extends Number> double calculateLinearA(
+            HashSet<T> list,
+            Function<T,V> getX,
+            Function<T,V> getY,
+            double meanX,
+            double meanY
+    ){
+        double numerateur = 0.0;
+        double denominateur = 0.0;
+
+        for( T item : list ){
+            if( getX.apply(item) == null || getY.apply(item) == null ){
+                continue;
+            }
+            numerateur += ( getX.apply(item).doubleValue() - meanX ) * ( getY.apply(item).doubleValue() - meanY );
+            denominateur += ( getX.apply(item).doubleValue() - meanX ) * ( getX.apply(item).doubleValue() - meanX );
+        }
+        return numerateur / denominateur;
+    }
+
+    public static double calculateLinearB(
+            double meanX,
+            double meanY,
+            double valueA
+    ){
+        return meanY - valueA * meanX;
+    }
+
 }