Functions: Add,od,constructors,len

src/main/java/ch/hepia/numeric/Vector.java

 package ch.hepia.numeric;
 
 import java.util.List;
+import java.util.ArrayList;
 import java.util.function.DoubleFunction;
 import java.util.function.Function;
 
 final public class Vector {
+    private List<Double> values;
+
     private Vector() {}
     private Vector(Double... elements) {
-        throw new UnsupportedOperationException("This feature isn't implemented yet");
+        List<Double> vec = new ArrayList<>();
+        for (double elem : elements){vec.add(elem);}
+        this.values = vec;
     }
     private Vector(List<Double> elements) {
-        throw new UnsupportedOperationException("This feature isn't implemented yet");
+        this.values = elements;
     }
 
     public Transposed t() {
@@ -18,18 +23,22 @@ final public class Vector {
     }
 
     public int len() {
-        throw new UnsupportedOperationException("This feature isn't implemented yet");
+        return this.values.size(); 
     }
 
     public double get(int i) {
-        throw new UnsupportedOperationException("This feature isn't implemented yet");
+        return this.values.get(i);
     }
     void set(int i, double value) {
-        throw new UnsupportedOperationException("This feature isn't implemented yet");
+        this.values.set(i, value);
     }
 
     public Vector add(Vector that) {
-        throw new UnsupportedOperationException("This feature isn't implemented yet");
+        List<Double> newVec = new ArrayList<>();
+        for(int i=0; i < this.len();i++){
+            newVec.add(this.get(i)+that.get(i));    
+        }
+        return new Vector(newVec);
     }
 
     public Vector mul(double m) {
@@ -77,7 +86,7 @@ final public class Vector {
     }
 
     public static Vector of(Double... elements) {
-        throw new UnsupportedOperationException("This feature isn't implemented yet");
+        return new Vector(elements);
     }
 
     public static Vector of(List<Double> elements) {