Post-8

• Review Modules 9 and 10 up to the place in Module 10 where we stopped on Thursday. Include in your review the parts we did not cover in class.

• Complete all in-class exercises in Modules 9 (from 6 onwards) and up through exercise 11 in Module 10. Don't forget to upload these in BB.

• Recall the example in Module 9 in which we rotated the elements of an array rightwards. Consider now a left rotation of an array:

  

  Here, elements are shifted leftwards, and an element that is shifted "off the left end" is shifted into the rightmost position. We have described a left rotation by 1 position (each element gets shifted by one spot). One can generalize this to a rotation in which each element moves k spots to the left. An example with k=2 is shown above.

  Write a program called LeftRotate.java that achieves a left rotation of the array int[] A={1,4,9,16,25}.

  Then, write a program called LeftRotateByK.java that achieves a left rotation of the array int[] A={1,4,9,16,25} by k positions, where k is a variable you can change in the program. Test it out for k=2, k=3 and k=5.

• Consider the array

  	int[] histogram = {2, 3, 8, 2, 1, 0, 3, 0, 6, 3};
  

  Think of the elements in here as the heights of rectangles that will be drawn along the x-axis using DrawTool as shown below:

  

  Such a picture is called a histogram. Write a program called Histogram.java that takes the histogram array and draws the rectangles. Don't forget that the width of each rectangle is slightly less than 1.0 and that you need DrawTool.java in the same directory.

• Now, we'll use the above idea to construct and display a histogram using data. Consider this array of real-valued data:

  	double[] data = {8.5, 6.6, 2.7, 2.1, 9.4, 0.9, 
  			 2.1, 6.2, 8.3, 1.2, 2.2, 0.3, 
  			 9.3, 2.6, 3.8, 2.5, 6.8, 8.1, 
  			 8.8, 9.5, 1.8, 8.2, 1.5, 2.9, 
  			 8.9, 3.1, 2.9, 4.6};
  

  The above data was used to count how many data values are in the range 0 to 1 (answer: 2), how many in the range 1 to 2 (answer: 3), etc. Thus, this is the data used to generate the histogram counts in the previous exercise. Write a program called HistogramGeneration.java that takes the data array, uses it to generate a corresponding histogram array and draws the rectangles.

• Don't forget your reflection exercise!

Recommended, but not required:
This week, hot on the heels of Watson's success, we'll explore natural language processing.

• Start by reviewing this (4-minute video) story about Watson.
• Find a website that explains the challenge of writing programs that understand natural languages. This is an active area of research called Natural Language Processing (NLP).
• What are other examples of NLP? Can you find software written in Java that performs NLP?
• Undoubtedly, you have "talked" to a computer program on the phone, for example, when you've called an airline or a bank, or phone company. Is this an example of NLP? Or is the computational challenge something else?
• What other major defeat of a human occurred at the hands of an IBM computer?