2. Functions

Overview.

In this chapter, we consider a concept that has as profound an impact on control flow as do conditionals and loops: the function, which allows us to transfer control back and forth between different pieces of code. Functions are important because they allow us to clearly separate tasks within a program and because they provide a general mechanism that enables us to reuse code.

2.1 Static Methods introduces the Java mechanism (the static method) for implementing functions.
2.2 Libraries and Clients describes how to group related static methods into libraries to enable modular programming.
2.3 Recursion considers the idea of a function calling itself. This possiblility is known as recursion.
2.4 Percolation presents a case study that uses Monte Carlo simulation to study a natural model known as percolation.

Java programs in this chapter.

REF PROGRAM DESCRIPTION

2.1.1 Newton.java create a function for computing the square root function

2.1.2 Gaussian.java implement functions related to the Gaussian distribution

2.1.3 Coupon.java design a modular program for coupon collector

2.1.4 PlayThatTune.java synthesize more realistic sound using harmonics

2.2.1 StdRandom.java create a library to generate random numbers

2.2.2 StdArrayIO.java create a library to read and show 1D and 2D arrays

2.2.3 IFS.java simulate an iterated function system

2.2.4 StdStats.java create a library to analyze statistics

2.2.5 StdStats.java create a library to plot data values

2.2.6 Bernoulli.java verify the Gaussian approximation to the binomial distribution

2.3.1 Euclid.java Euclid's algorithm for the greatest common divisor

2.3.2 TowersOfHanoi.java devise a solution to the Towers of Hanoi problem

2.3.3 Beckett.java provide stage instructions for Beckett's play using a Gray code

2.3.4 Htree.java draw recursive graphics

2.3.5 Brownian.java draw a Brownian bridge

2.4.1 VerticalPercolation.java check whether a system vertically percolates

2.4.2 VerticalPercolation.java check whether a system vertically percolates

2.4.3 Visualize.java visualize large random percolation instances

2.4.4 Estimate.java estimate the percolation probability

2.4.5 Percolation.java check whether a system percolates

2.4.6 PercPlot.java plot percolation probability vs. site vacancy probability

REF	PROGRAM	DESCRIPTION
2.1.1	Newton.java	create a function for computing the square root function
2.1.2	Gaussian.java	implement functions related to the Gaussian distribution
2.1.3	Coupon.java	design a modular program for coupon collector
2.1.4	PlayThatTune.java	synthesize more realistic sound using harmonics
2.2.1	StdRandom.java	create a library to generate random numbers
2.2.2	StdArrayIO.java	create a library to read and show 1D and 2D arrays
2.2.3	IFS.java	simulate an iterated function system
2.2.4	StdStats.java	create a library to analyze statistics
2.2.5	StdStats.java	create a library to plot data values
2.2.6	Bernoulli.java	verify the Gaussian approximation to the binomial distribution
2.3.1	Euclid.java	Euclid's algorithm for the greatest common divisor
2.3.2	TowersOfHanoi.java	devise a solution to the Towers of Hanoi problem
2.3.3	Beckett.java	provide stage instructions for Beckett's play using a Gray code
2.3.4	Htree.java	draw recursive graphics
2.3.5	Brownian.java	draw a Brownian bridge
2.4.1	VerticalPercolation.java	check whether a system vertically percolates
2.4.2	VerticalPercolation.java	check whether a system vertically percolates
2.4.3	Visualize.java	visualize large random percolation instances
2.4.4	Estimate.java	estimate the percolation probability
2.4.5	Percolation.java	check whether a system percolates
2.4.6	PercPlot.java	plot percolation probability vs. site vacancy probability

Click on the program name to access the Java code; click on the reference number for a brief description; read the textbook for a full discussion.

Exercises.

Include a link.