diff --git a/Doc/Sd1/inheritance.xml b/Doc/Sd1/inheritance.xml
index c2c1eff167c24b16b9901fdabb8ee1f2977e93bd..6aa8b801f06283ed07c647b4873a15cd2dca7b21 100644
--- a/Doc/Sd1/inheritance.xml
+++ b/Doc/Sd1/inheritance.xml
@@ -115,6 +115,8 @@ c.move(1, 5).move(-3, 7);</programlisting>
half its original size. Add a corresponding scale(...) method to
the Figure inheritance hierarchy which allows for operation
chaining as well.</para>
+
+ <para>Provide appropriate unit tests.</para>
</question>
<answer>
@@ -138,8 +140,75 @@ c.move(1, 5).move(-3, 7);</programlisting>
<para>This method has to be implemented in our two concrete
classes <classname>Circle</classname> and
- <classname>Rectangle</classname>. Provide appropriate unit
- tests.</para>
+ <classname>Rectangle</classname>.</para>
+
+ <para>Sensible unit tests may be based on the observation
+ that:</para>
+
+ <itemizedlist>
+ <listitem>
+ <para>A figure's perimeter grows linear with the scaling
+ factor.</para>
+ </listitem>
+
+ <listitem>
+ <para>A figure's area grows linear with the scaling factor's
+ square.</para>
+ </listitem>
+ </itemizedlist>
+ </answer>
+ </qandaentry>
+ </qandadiv>
+ </qandaset>
+ </section>
+
+ <section xml:id="sd1SectFigureToString">
+ <title>Providing <methodname
+ xlink:href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#toString--">toString()</methodname>
+ methods</title>
+
+ <qandaset defaultlabel="qanda" xml:id="sd1QandaFigureToString">
+ <qandadiv>
+ <qandaentry>
+ <question>
+ <para>Consider:</para>
+
+ <programlisting language="none"> final Circle c = new Circle(-2, -1, 3.5);
+ final Rectangle r = new Rectangle(3, 1, 1.5, 4.4);
+
+ System.out.println(c);
+ System.out.println(r);</programlisting>
+
+ <para>This creates the following output:</para>
+
+ <programlisting language="none">de.hdm_stuttgart.mi.sd1.figure.model.Circle@659e0bfd
+de.hdm_stuttgart.mi.sd1.figure.model.Rectangle@2a139a55</programlisting>
+
+ <para>This result is due to the invocation of the <methodname
+ xlink:href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#toString--">toString()</methodname>
+ method being defined in the <classname
+ xlink:href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html">Object</classname>
+ superclass. Provide appropriate definitions in
+ <classname>Figure</classname>, <classname>Circle</classname> and
+ <classname>Rectangle</classname> to replace this output
+ by:</para>
+
+ <programlisting language="none">Circle (-2.0,-1.0), radius=3.5
+Rectangle (3.0,1.0), width=1.5, height=4.4</programlisting>
+
+ <para>Provide appropriate unit tests.</para>
+
+ <tip>
+ <para>You may access
+ <methodname>Figure.toString()</methodname> from derived
+ classes by using <code>super()</code>.</para>
+ </tip>
+ </question>
+
+ <answer>
+ <annotation role="make">
+ <para role="eclipse">Sd1/Figure/ToString</para>
+ </annotation>
</answer>
</qandaentry>
</qandadiv>
diff --git a/P/Sd1/Figure/ToString/.gitignore b/P/Sd1/Figure/ToString/.gitignore
new file mode 100644
index 0000000000000000000000000000000000000000..cf5fd6bb26d6450c8c63fb34295192784943cf5e
--- /dev/null
+++ b/P/Sd1/Figure/ToString/.gitignore
@@ -0,0 +1,5 @@
+/.settings
+/target
+/.classpath
+/.project
+/A1.log
diff --git a/P/Sd1/Figure/ToString/pom.xml b/P/Sd1/Figure/ToString/pom.xml
new file mode 100644
index 0000000000000000000000000000000000000000..9d03cbe7fffe885269f489135e5cbbbf35b9bf60
--- /dev/null
+++ b/P/Sd1/Figure/ToString/pom.xml
@@ -0,0 +1,45 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+ xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+ <modelVersion>4.0.0</modelVersion>
+
+ <parent>
+ <groupId>de.hdm-stuttgart.mi</groupId>
+ <artifactId>lecturenotes-pom</artifactId>
+ <version>1.0</version>
+ <relativePath>../../../pom.xml</relativePath>
+ </parent>
+
+ <groupId>de.hdm-stuttgart.de.sd1</groupId>
+ <artifactId>figure</artifactId>
+ <version>1.3</version>
+ <packaging>jar</packaging>
+
+ <name>figure</name>
+ <url>http://www.mi.hdm-stuttgart.de/freedocs</url>
+
+ <build>
+ <plugins>
+
+ <plugin>
+ <groupId>org.apache.maven.plugins</groupId>
+ <artifactId>maven-javadoc-plugin</artifactId>
+ <version>2.10.1</version>
+ <configuration>
+ <linksource>true</linksource>
+ <taglets>
+ <taglet>
+ <tagletClass>de.hdm_stuttgart.de.sd1.taglet.HtmlExtensionTaglet</tagletClass>
+ <tagletArtifact>
+ <groupId>de.hdm-stuttgart.de.sd1</groupId>
+ <artifactId>taglet</artifactId>
+ <version>1.0</version>
+ </tagletArtifact>
+ </taglet>
+ </taglets>
+ </configuration>
+ </plugin>
+
+ </plugins>
+ </build>
+
+</project>
diff --git a/P/Sd1/Figure/ToString/src/main/java/de/hdm_stuttgart/mi/sd1/figure/App.java b/P/Sd1/Figure/ToString/src/main/java/de/hdm_stuttgart/mi/sd1/figure/App.java
new file mode 100644
index 0000000000000000000000000000000000000000..d4dab0b975b4d060c1370fce33999d61589e42a4
--- /dev/null
+++ b/P/Sd1/Figure/ToString/src/main/java/de/hdm_stuttgart/mi/sd1/figure/App.java
@@ -0,0 +1,18 @@
+package de.hdm_stuttgart.mi.sd1.figure;
+
+import de.hdm_stuttgart.mi.sd1.figure.model.Circle;
+import de.hdm_stuttgart.mi.sd1.figure.model.Rectangle;
+
+public class App {
+
+ public static void main(String[] args) {
+
+ final Circle c = new Circle(-2, -1, 3.5);
+ final Rectangle r = new Rectangle(3, 1, 1.5, 4.4);
+
+ System.out.println(c);
+ System.out.println(r);
+
+ }
+
+}
diff --git a/P/Sd1/Figure/ToString/src/main/java/de/hdm_stuttgart/mi/sd1/figure/model/Circle.java b/P/Sd1/Figure/ToString/src/main/java/de/hdm_stuttgart/mi/sd1/figure/model/Circle.java
new file mode 100644
index 0000000000000000000000000000000000000000..ccfd6e4dfb5691c749db8ca57059c2d1ca279238
--- /dev/null
+++ b/P/Sd1/Figure/ToString/src/main/java/de/hdm_stuttgart/mi/sd1/figure/model/Circle.java
@@ -0,0 +1,45 @@
+package de.hdm_stuttgart.mi.sd1.figure.model;
+
+/**
+ *
+ */
+public class Circle extends Figure {
+
+ private double radius;
+
+ @Override
+ public String toString() {
+ return "Circle " + super.toString() + ", radius=" + radius;
+ }
+
+ /**
+ * Extending {@link Figure#Figure(double, double)} by adding parameter radius
+ * on top of center coordinates.
+ *
+ * @param x
+ * @param y
+ * @param radius
+ */
+ public Circle(final double x, final double y, final double radius) {
+ super(x, y);
+ setRadius(radius);
+ }
+
+ public double getArea() {
+ return radius * radius * Math.PI;
+ }
+
+ public double getPerimeter() {
+ return 2 * Math.PI * radius;
+ }
+
+ // Getter and setter methods for private attribute
+ public double getRadius() { return radius;}
+ public void setRadius(final double radius) { this.radius = radius;}
+
+ @Override
+ public Figure scale(final double factor) {
+ radius *= factor;
+ return this;
+ }
+}
diff --git a/P/Sd1/Figure/ToString/src/main/java/de/hdm_stuttgart/mi/sd1/figure/model/Figure.java b/P/Sd1/Figure/ToString/src/main/java/de/hdm_stuttgart/mi/sd1/figure/model/Figure.java
new file mode 100644
index 0000000000000000000000000000000000000000..d6c3ef10e65f29d86d2270a65d38e5d7b21b7f1a
--- /dev/null
+++ b/P/Sd1/Figure/ToString/src/main/java/de/hdm_stuttgart/mi/sd1/figure/model/Figure.java
@@ -0,0 +1,64 @@
+package de.hdm_stuttgart.mi.sd1.figure.model;
+
+/**
+ *
+ */
+public abstract class Figure {
+
+ private double x,y;
+
+
+
+ @Override
+ public String toString() {
+ return "(" + x + ',' + y + ')';
+ }
+
+ /**
+ * Creating a figure with given center coordinates
+ *
+ * @param x
+ * @param y
+ */
+ public Figure(final double x, final double y) {
+ setX(x);
+ setY(y);
+ }
+
+ // To be implemented in derived classes Rectangle and Circle
+ /**
+ *
+ * @param factor Scale the current figure by this value.
+ * @return The current object.
+ */
+ public abstract Figure scale(double factor);
+
+ /**
+ *
+ * @return The current figure's area e.g. with times height in case of a rectangle
+ */
+ public abstract double getArea();
+
+ /**
+ * @return The current figure's perimeter e.g. with 2 * (height + width) in case of a rectangle
+ */
+ public abstract double getPerimeter();
+
+ public double getX() { return x;}
+ public void setX(final double x) { this.x = x;}
+ public double getY() { return y;}
+ public void setY(final double y) { this.y = y;}
+
+ /**
+ * Translating a figure by a given vector (x,y).
+ *
+ * @param x
+ * @param y
+ * @return The current object.
+ */
+ public final Figure move(final double x, final double y) {
+ setX(getX() + x);
+ setY(getY() + y);
+ return this;
+ }
+}
\ No newline at end of file
diff --git a/P/Sd1/Figure/ToString/src/main/java/de/hdm_stuttgart/mi/sd1/figure/model/Rectangle.java b/P/Sd1/Figure/ToString/src/main/java/de/hdm_stuttgart/mi/sd1/figure/model/Rectangle.java
new file mode 100644
index 0000000000000000000000000000000000000000..3b2ca4f1955af24fbf2841c037b65d0822bc5d56
--- /dev/null
+++ b/P/Sd1/Figure/ToString/src/main/java/de/hdm_stuttgart/mi/sd1/figure/model/Rectangle.java
@@ -0,0 +1,54 @@
+package de.hdm_stuttgart.mi.sd1.figure.model;
+
+public class Rectangle extends Figure {
+
+// Instance variables representing a rectangle's additional parameters
+ private double width, height;
+
+ @Override
+ public String toString() {
+ return "Rectangle " + super.toString() + ", width=" + width + ", height=" + height;
+ }
+
+ /**
+ * Extending {@link Figure#Figure(double, double)} by adding parameters
+ * width and height on top of center coordinates.
+ *
+ * @param x
+ * @param y
+ * @param width
+ * @param height
+ */
+ public Rectangle(final double x, final double y, final double width, final double height) {
+ super(x, y);
+ setWidth(width);
+ setHeight(height);
+ }
+
+ /**
+ * @return The rectangle's area.
+ */
+ public double getArea() {
+ return width * height;
+ }
+
+ /**
+ * @return The rectangle's perimeter.
+ */
+ public double getPerimeter() {
+ return 2 * (width + height);
+ }
+
+ // Getter and setter methods for private attributes
+ public double getWidth() { return width;}
+ public void setWidth(final double width) { this.width = width;}
+ public double getHeight() { return height;}
+ public void setHeight(final double height) { this.height = height;}
+
+ @Override
+ public Figure scale(final double factor) {
+ width *= factor;
+ height *= factor;
+ return this;
+ }
+}
\ No newline at end of file
diff --git a/P/Sd1/Figure/ToString/src/test/java/de/hdm_stuttgart/mi/sd1/figuretest/FigureTest.java b/P/Sd1/Figure/ToString/src/test/java/de/hdm_stuttgart/mi/sd1/figuretest/FigureTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..7c2fdb71b4e51c15581c8c462a4ef5b572c5d2b7
--- /dev/null
+++ b/P/Sd1/Figure/ToString/src/test/java/de/hdm_stuttgart/mi/sd1/figuretest/FigureTest.java
@@ -0,0 +1,119 @@
+package de.hdm_stuttgart.mi.sd1.figuretest;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import de.hdm_stuttgart.mi.sd1.figure.model.Circle;
+import de.hdm_stuttgart.mi.sd1.figure.model.Rectangle;
+
+public class FigureTest {
+ static final double accuracyLimit = 1.E-15; // Rounding accuracy limit with respect to arithmetic operations
+
+ @Test
+ public void circleTranslation() {
+
+ final double
+ x = 3., y = 4., // circle's center coordinates (3, 4)
+ transX = 3., transY = -2., // translation vector (3, -2)
+ expectX = x + transX, expectY = y + transY; // translated circle's coordinates (6, 2)
+
+ final Circle c = new Circle(x, y, 3.0);
+ c.move(transX, transY);
+
+ Assert.assertEquals(expectX, c.getX(), accuracyLimit);
+ Assert.assertEquals(expectY, c.getY(), accuracyLimit);
+ }
+
+ @Test
+ public void rectangleTranslation() {
+
+ final double
+ x = 2., y = 6.5, // rectangle's center coordinates (2, 6.5)
+ transX = 4., transY = 1., // translation vector (3, -2)
+ expectX = x + transX, expectY = y + transY; // translated circle's coordinates (6, 2)
+
+ final Rectangle r = new Rectangle(x, y, 2., 1.);
+ r.move(transX, transY);
+ Assert.assertEquals(expectX, r.getX(), accuracyLimit);
+ Assert.assertEquals(expectY, r.getY(), accuracyLimit);
+ }
+
+ @Test
+ public void circlePerimeterAndArea() {
+ final double
+ radius = 1.,
+ expectedPerimeter = 2 * Math.PI * radius,
+ expectedArea = Math.PI * radius * radius;
+
+ final Circle c = new Circle(3, 4, radius);
+
+ Assert.assertEquals(expectedPerimeter, c.getPerimeter(), accuracyLimit);
+ Assert.assertEquals(expectedArea, c.getArea(), accuracyLimit);
+ }
+
+ @Test
+ public void rectanglePerimeterAndArea() {
+ final double
+ width = 2.,
+ height = 1.,
+ expectedPerimeter = 2 * (width + height),
+ expectedArea = width * height;
+
+ final Rectangle r = new Rectangle(1, 3, width, height);
+
+ Assert.assertEquals(expectedPerimeter, r.getPerimeter(), accuracyLimit);
+ Assert.assertEquals(expectedArea, r.getArea(), accuracyLimit);
+ }
+
+ @Test
+ public void rectangleScale() {
+ final double
+ width = 2.,
+ height = 1.,
+ factor = 3;
+
+ final Rectangle r = new Rectangle(1, 3, width, height);
+
+ final double
+ originalPerimeter = r.getPerimeter(),
+ originalArea = r.getArea(),
+ expectedPerimeter = originalPerimeter * factor, // Perimeter is linear with respect to scale factor
+ expectedArea = originalArea * factor * factor; // Area is quadratic with respect to scale factor
+
+ r.scale(factor);
+
+ Assert.assertEquals(expectedPerimeter, r.getPerimeter(), accuracyLimit);
+ Assert.assertEquals(expectedArea, r.getArea(), accuracyLimit);
+ }
+
+ @Test
+ public void circleScale() {
+ final double
+ radius = 2.,
+ factor = 0.7;
+
+ final Circle c = new Circle(-2, 5, radius);
+
+ final double
+ originalPerimeter = c.getPerimeter(),
+ originalArea = c.getArea(),
+ expectedPerimeter = originalPerimeter * factor, // Perimeter is linear with respect to scale factor
+ expectedArea = originalArea * factor * factor; // Area is quadratic with respect to scale factor
+
+ c.scale(factor);
+
+ Assert.assertEquals(expectedPerimeter, c.getPerimeter(), accuracyLimit);
+ Assert.assertEquals(expectedArea, c.getArea(), accuracyLimit);
+ }
+
+ @Test
+ public void circleToString() {
+ final Circle c = new Circle(-2, -1, 3.5);
+ Assert.assertEquals("Circle (-2.0,-1.0), radius=3.5", c.toString());
+ }
+ @Test
+ public void rectangleToString() {
+ final Rectangle r = new Rectangle(3, 1, 1.5, 4.4);
+ Assert.assertEquals("Rectangle (3.0,1.0), width=1.5, height=4.4", r.toString());
+ }
+}
diff --git a/P/pom.xml b/P/pom.xml
index 6454f0ae82d9c67db58ae9dbbc22b1484a4a9953..ed8e2754a661c7193330dc752b795be57dd38a58 100644
--- a/P/pom.xml
+++ b/P/pom.xml
@@ -47,6 +47,7 @@
<module>Sd1/Figure/BaseClass</module>
<module>Sd1/Figure/Scale</module>
+ <module>Sd1/Figure/ToString</module>
<module>Sd1/Gcd/V1</module>