| reddyfire |
Apr 7th, 2008 10:10 PM |
Complex Number Calculator
So I'm trying to create a program to calculate complex numbers. The program contains two parts of code the Complex.java which contains the formulas for calculating the math and the calculator.java that asks for the input and computes everything. My program runs the way it is supposed to except for the fact that it doesn't register negative numbers when they are entered. Here is my code.
:
import java.util.StringTokenizer;
public class Complex
{
private double real, imaginary;
public Complex()
{
real=0;
imaginary=0;
}
public Complex(double r, double i)
{
real = r;
imaginary = i;
}
public String toString()
{
String R = "";
String I = "";
String r = Double.toString(real);
String i = Double.toString(imaginary);
int pointR = r.indexOf(".");
int pointI = i.indexOf(".");
int lengthR = r.length();
int lengthI = i.length();
// check if values are whole and cut off the ".0" part
if (r.charAt(lengthR-1)=='0')
{
for (int k = 0; k < pointR; k++)
{
R = R + r.charAt(k);
}
}
if (i.charAt(lengthI-1)=='0')
{
for (int k = 0; k < pointI; k++)
{
if (i.charAt(k) == '-')
I = I + i.charAt(k) + " ";
else
I = I + i.charAt(k);
}
}
// all IFs are executed if the values are NOT whole
// when REAL is 0 and IMAGINARY is POSITIVE
if (R.equals("0") && imaginary > 0 && R.equals("") && I.equals(""))
{
String s = ("(" + "i" + ")");
return s;
}
// when REAL is 0 and IMAGINARY is NEGATIVE
if (R.equals("0") && imaginary < 0 && R.equals("") && I.equals(""))
{
String s = ("(" + "-" + "i" + ")");
return s;
}
// when REAL is 0 and IMAGINARY is 0
if (R.equals("0") && imaginary == 0.0 && R.equals("") && I.equals(""))
{
String s = ("(0)");
return s;
}
// when REAL is POSITIVE and IMAGINARY is NEGATIVE
if (real > 0.0 && imaginary < 0.0 && R.equals("") && I.equals(""))
{
for (int k = 0; k < (lengthI-1); k++)
{
I = I + i.charAt(k);
if (i.charAt(k) == '-')
{
I = I + " ";
}
}
String s = ("("+ r + " " + I + "i" + ")");
return s;
}
// when REAL is POSITVE and IMAGINARY is 0
if (real > 0.0 && imaginary == 0.0 && R.equals("") && I.equals(""))
{
String s = ("(" + R + ")");
return s;
}
// when REAL is NEGATIVE and IMAGINARY is 0
if (real < 0.0 && imaginary == 0.0 && R.equals("") && I.equals(""))
{
String s = ("(" + R + ")");
return s;
}
// when BOTH ARE NEGATIVE
if (real < 0.0 && imaginary < 0.0 && R.equals("") && I.equals(""))
{
String s = ("(" + R + " " + I + "i" + ")");
return s;
}
// when REAL is NEGATIVE and IMAGINARY is POSITIVE
if (real < 0.0 && imaginary > 0.0 && R.equals("") && I.equals(""))
{
String s = ("(" + r + " + " + i + "i" + ")");
return s;
}
// when BOTH are POSITIVE
if (real > 0.0 && imaginary > 0.0 && R.equals("") && I.equals(""))
{
String s = ("(" + r + " + " + i + "i" + ")");
return s;
}
// when values ARE WHOLE
String s = ("(" + R + " + " + I + "i" + ")");
return s;
}
public Complex add( Complex c)
{
return new Complex (real+c.real, imaginary+c.imaginary);
}
public Complex subtract(Complex c)
{
return new Complex (real-c.real, imaginary-c.imaginary);
}
public Complex multiply(Complex c)
{
Complex C = new Complex (real*c.real - imaginary*c.imaginary, real*c.imaginary + c.real*imaginary);
return C;
}
public Complex divide(Complex c)
{
double Real = (real*c.real+imaginary*c.imaginary)/(Math.pow(c.real, 2) + Math.pow(c.imaginary, 2));
double Imaginary = (imaginary*c.real - real*c.imaginary)/(Math.pow(c.real, 2) + Math.pow(c.imaginary, 2));
return new Complex(Real, Imaginary);
}
}
import java.io.*;
import java.util.StringTokenizer;
public class Calculator
{
public static void main(String[] args)
{
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
Complex num1, num2, result = new Complex();
char op;
boolean more;
System.out.println("\n Complex number calculation program \n");
do
{
num1 = readComplex(in, "Enter the 1st number you would like: ");
num2 = readComplex(in, "Enter the 2nd number you would like: ");
op = readChar(in, "Enter the operation to be preformed '+, -, *, or /': ", "+-*/");
switch (op)
{
case '+': result = num1.add(num2);
break;
case '*': result = num1.multiply(num2);
break;
case '/': result = num1.divide(num2);
break;
case '-': result = num1.subtract(num2);
}
System.out.println(num1+" "+op+" "+num2+" = "+result);
more = (readChar(in, "Want to do another calculation? (y/n): ", "yn") !='n');
}
while (more);
System.out.println("\n Calculations have been completed \n");
}
// Method to read a complex number
public static Complex readComplex(BufferedReader in, String s)
{
System.out.print(s);
double real = 0;
double img = 0;
boolean doit = true;
//begins loop for user input
while (true)
{
try
{
//reads input from user and checks for "i" for correct format
String inp = in.readLine();
int qwer = inp.indexOf("i");
if (inp.indexOf("i") == -1)
{
throw new IOException();
}
//Tokenizes the sring by using delimters which ar +,-,_,tab, newline, i
StringTokenizer t = new StringTokenizer(inp, "+- //t/n/ri");
//checks to see if there are tokens and store the value in double "real"
if (t.hasMoreTokens())
{
real = Double.parseDouble(t.nextToken());
}
else throw new IOException();
//check if there are tokens and store value in double "img"
if (t.hasMoreTokens())
{
img = Double.parseDouble(t.nextToken());
}
else throw new IOException();
//if the program has no problems then set vaule of doit to true
doit = true;
}
//handles the NumberFormatException
catch (NumberFormatException e)
{
System.out.print ("\n Incorrect format, try again (num + numi): ");
doit = false;
}
//handles the IOException
catch (IOException e)
{
System.out.print ("\n Incorrect format, try again (num + numi): ");
doit = false;
}
//If no problems then it creates a complex object with real and img variables.
if (doit == true)
{
Complex c = new Complex(real, img);
return c;
}
}
}
// Method reads the first character of a string
public static char readChar(BufferedReader in, String prompt, String chars)
{
System.out.print (prompt);
String inp = "";
while (true)
{
try
{
inp = in.readLine();
}
catch (IOException e)
{
System.out.println ("\n There is an Error!");
}
if (chars.indexOf(inp.charAt(0)) >= 0 )
return chars.charAt(chars.indexOf(inp.charAt(0)));
else
System.out.print("\nIncorrect value (use: + - / *): ");
}
}
}
An example of the error I am getting is lets say I take a set of complex numbers like this (-1+2i) + (-3+4i) it should return -4 + 6i but instead it is printing (1+2i) + (3 + 4i) = 4 + 6i. It completely ignores the negative numbers and puts them in as positive. If anyone could let me know what I am doing wrong I would greatly appreciate it. Thanks. |
