Created Complex-class which inherits from Vector2D.

src/main/java/edu/ntnu/stud/chaosgame/model/Complex.java

+package edu.ntnu.stud.chaosgame.model;
+
+/**
+ * Class representing a complex number.
+ */
+public class Complex extends Vector2D{
+
+  /**
+   * Create a new complex number.
+   */
+  public Complex(double real, double imag) {
+    super(real, imag);
+  }
+
+  /**
+   * Get the square root of the complex number.
+   * 
+   * @return The square root of the complex number.
+   */
+  public Complex sqrt() {
+    double r = Math.sqrt(Math.sqrt(getX0() * getX0() + getX1() * getX1()));
+    double theta = Math.atan2(getX1(), getX0()) / 2;
+    return new Complex(r * Math.cos(theta), r * Math.sin(theta));
+  }
+
+}

src/main/java/edu/ntnu/stud/chaosgame/model/Vector2D.java

@@ -16,7 +16,12 @@ public class Vector2D {
   private double x1;
 
   /**
-   * Create a new 2D vector.
+   * Create a new 2D vector; default constructor.
+   */
+  public Vector2D() {}
+
+  /**
+   * Create a new 2D vector; parameterized.
    *
    * @param x0 The x0 component of the vector.
    * @param x1 The x1 component of the vector.