Class FindPrincipal

java.lang.Object
  FindPrincipal

public class FindPrincipal
extends java.lang.Object

FindPrincipal.java
Solution for CS 201 HW 1 problem 2
Program to calculate the maximum principal available at a given interest rate, mortgage length, and monthly payment

Constructor Summary

FindPrincipal()

Method Summary

static double	find(double mortgage, double interest, double years) Calls findBetween 0 and the upper bound
static double	findBetween(double mortgage, double interest, double years, double lo, double hi) Finds the ideal principal using a binary search of whether the monthly payment is too high or too low
static void	main(java.lang.String[] args) Calls testFind with mortgage = 1200.00, interst = 7.00, and years = 30.0.
static void	testFind(double mortgage, double interest, double years) Prints the output of find in the format find(mortgage, interest, years) = principal
static double	upperBound(double mortgage, double interest, double years) Calculates an upper bound for the principal

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FindPrincipal

public FindPrincipal()

Method Detail

find

public static double find(double mortgage,
                          double interest,
                          double years)

Calls findBetween 0 and the upper bound

Parameters:

mortgage - the monthly mortgage payment that the user can afford

interest - the interest rate

years - the length of the mortgage

Returns:

the maximum principal that the user can afford

findBetween

public static double findBetween(double mortgage,
                                 double interest,
                                 double years,
                                 double lo,
                                 double hi)

Finds the ideal principal using a binary search of whether the monthly payment is too high or too low

Parameters:

mortgage - the monthly mortgage payment that the user can afford

interest - the interest rate

years - the length of the mortgage

lo - the lowest possible principal to examine

hi - the hightest possible principal to examine

Returns:

the maximum principal that the user can afford

upperBound

public static double upperBound(double mortgage,
                                double interest,
                                double years)

Calculates an upper bound for the principal

Parameters:

mortgage - the monthly mortgage payment that the user can afford

interest - the interest rate

years - the length of the mortgage

Returns:

a value greater than the principal the user can afford

testFind

public static void testFind(double mortgage,
                            double interest,
                            double years)

Prints the output of find in the format find(mortgage, interest, years) = principal

Parameters:

mortgage - the monthly mortgage payment that the user can afford

interest - the interest rate

years - the length of the mortgage

main

public static void main(java.lang.String[] args)

Calls testFind with mortgage = 1200.00, interst = 7.00, and years = 30.0. Essentially used for testing