1.5 Game 2302-0115: working with column matrices, points, and  (Page 7/9)

By now, you should have no difficulty understanding how the output shown in Figure 3 was produced by the code shown in Listing 8 . Note, however, that the last value on the third row should be 0.0 instead of the extremelysmall value shown. This is an example of an inherent problem having to do with comparing double or float values with other double or float values for absolute equality.

Documentation for the GM2D03 library

Click here to download a zip file containing standard javadoc documentation for the library named GM2D03 . Extract the contents of the zip file into an empty folder and open the filenamed index.html in your browser to view the documentation.

Although the documentation doesn't provide much in the way of explanatory text (see Listing 11 and the explanations given above) , the documentation does provide a good overview of the organization and structure ofthe library. You may find it helpful in that regard.

Homework assignment

Your homework assignment for this module was to study Kjell's tutorial through Chapter 2 - Column and Row Matrix Addition .

The homework assignment for the next module is to study the Kjell tutorial through Chapter 3 - Vector Addition .

In addition to studying the Kjell material, you should read at least the next two modules in this collection and bring your questions about thatmaterial to the next classroom session.

Finally, you should have begun studying the physics material at the beginning of the semester and you should continue studying one physics moduleper week thereafter. You should also feel free to bring your questions about that material to the classroom for discussion.

Run the programs

I encourage you to copy the code from Listing 12 , Listing 13 , and Listing 14 . Compile the code and execute it in conjunction with the game-math libraryprovided in Listing 11 . Experiment with the code, making changes, and observing the results of your changes. Make certain that you can explain why your changesbehave as they do.

Summary

In this module, you learned how to compare column matrices for equality, compare two points for equality, compare two vectors for equality, add onecolumn matrix to another, subtract one column matrix from another, and get a displacement vector from one point to another.

What's next?

The next module in the collection will show one way for you to visualize column matrices in graphical form.

In the module following that one, you will learn:

• How to add two or more vectors.
• About the head-to-tail rule in vector addition.
• About the vector addition parallelogram.
• About the relationship between the length of the sum of vectors and the sum of the lengths of the vectors.
• How to add a vector to a point.
• How to get the length of a vector.
• How to represent an object in different coordinate frames.

Miscellaneous

This section contains a variety of miscellaneous information.