Difference between revisions of "CISC181 S2017 Lab8"

Revision as of 13:34, 14 April 2017

Preliminaries

• Make a new project with n = 8 (following these instructions)
• Name your main class "Lab8" (when creating a new module in the instructions above, in the Java class name field)
• Modify Lab8.java by adding your name and section number in a comment before the Lab8 class body.

Instructions

In this lab you will analyze text files by breaking them into n-grams at the character level, and use those n-grams to generate random text in the same "style" (in a statistical sense).

Suppose, for example, that you are working with 2-grams, and you have found that 80% of the time "th" is followed by "e ", 10% by "is", 7% by "at", and 3% by "es" (made-up numbers!). Then, when you are generating text, after you have generated "th" you should randomly choose "e " with probability 0.8, "is" with probability 0.1, "at" with probability 0.07, and "es" with probability 0.03.

RandomWriter

You are to implement a Java public class RandomWriter that provides a random writing application. Your class should have a two-argument constructor that takes:

• String source: The name of an input file to read and analyze
• int n A non-negative number indicating the length of each "gram," or character sequence, to break the file into

and also a method generateText() that takes the following two parameters:

• int length A non-negative number of characters to generate.
• String result: The name of the output file

Testing

In main(), run your code on the following files:

• getty
• doi
• bts
• greatexp

Generate approximately 500 characters of text for each input. Print the text in reasonable length lines, breaking only at spaces (not in the middle of a word). Do this for 1-grams, 2-grams, 3-grams, 4-grams, and 5-grams.

Acknowledgments

This assignment is shamelessly copied from one created by David Matuszek at the University of Pennsylvania.