Jampack

Class Z

java.lang.Object

Jampack.Z

public class Z
extends java.lang.Object

Z is a mutable complex variable class. It is designed to perform complex arithmetic without creating a new Z at each operation. Specifically, binary operations have the form c.op(a,b), in which a, b, and c need not be different. The method places the complex number a.op.b in c. The method also returns a pointer to c. Thus the class supports two styles of programming. For example to compute e = a*b + c*d you can write

z1.Times(a,b)
z2.Times(c,d)
e.Plus(z1,z2)

or

e.Plus(z1.Times(a,b), z2.Times(a,b))

Since objects of class Z are mutable, the use of the assignment operator "=" with these objects is deprecated. Use Eq.

The functions are reasonably resistent to overflow and underflow. But the more complicated ones could almost certainly be improved.

Field Summary

Fields

Modifier and Type	Field and Description
static Z	I Imaginary unit.
double	im The imaginary part of Z.
static Z	ONE Complex 1.
double	re The real part of Z.
static Z	ZERO Complex 0.

Constructor Summary

Constructors

Constructor and Description
Z() Creates a Z and initializes it to zero.
Z(double x) Creates a Z and initializes its real part.
Z(double x, double y) Creates a Z and initializes its real and imaginary parts.
Z(Z a) Creates a Z and initializes it to another Z.

Method Summary

Modifier and Type	Method and Description
static double	abs(Z z) Computes the absolute value of a Z.
static double	abs1(Z z) Computes the 1-norm of a Z
Z	Conj(Z a) Computes the conjugate of a Z.
Z	Div(Z a, double b) Computes the quotient of a Z and a double.
Z	Div(Z a, Z b) Computes the quotient of two Z's.
Z	Eq(double a, double b) Resets the real and imaginary parts of a Z.
Z	Eq(Z a) Resets the real and imaginary parts of a Z to those of another Z.
Z	Exch(Z a) Interchanges the real and imaginary parts of two Z's.
boolean	IsEqual(Z z1, Z z2) Tests two Z'z for equality.
Z	Minus(Z a) Computes unary minus of a Z.
Z	Minus(Z a, Z b) Computes the difference of two Z's.
Z	Plus(Z a, Z b) Computes the sum of two Z's.
Z	Sqrt(Z a) Computes the principal value of the square root of a Z.
Z	Times(double a, Z b) Computes the product of a double and a Z.
Z	Times(Z a, Z b) Computes the product of two Z's.

Methods inherited from class java.lang.Object

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

Field Detail

ONE

public static final Z ONE

Complex 1.

ZERO

public static final Z ZERO

Complex 0.

I

public static final Z I

Imaginary unit.

re

public double re

The real part of Z.

im

public double im

The imaginary part of Z.

Constructor Detail

Z

public Z()

Creates a Z and initializes it to zero.

Z

public Z(double x,
         double y)

Creates a Z and initializes its real and imaginary parts.

Parameters:

x - a double

y - a double

Z

public Z(double x)

Creates a Z and initializes its real part.

Parameters:

x - a double

Z

public Z(Z a)

Creates a Z and initializes it to another Z.

Parameters:

a - a Z

Method Detail

IsEqual

public boolean IsEqual(Z z1,
                       Z z2)

Tests two Z'z for equality.

Parameters:

z1 - a Z

z2 - a Z

Returns:

true if z1=z2, otherwise false

Eq

public Z Eq(Z a)

Resets the real and imaginary parts of a Z to those of another Z.

Parameters:

a - a Z

Returns:

this = a;

Eq

public Z Eq(double a,
            double b)

Resets the real and imaginary parts of a Z.

Parameters:

a - a double

b - a double

Returns:

this = a + ib

Exch

public Z Exch(Z a)

Interchanges the real and imaginary parts of two Z's.

Parameters:

a - a Z

Returns:

this = a, with a set to the original value of this.

abs1

public static double abs1(Z z)

Computes the 1-norm of a Z

abs

public static double abs(Z z)

Computes the absolute value of a Z.

Parameters:

z - a Z

Returns:

the absolute vaue of Z

Conj

public Z Conj(Z a)

Computes the conjugate of a Z.

Parameters:

a - a Z

Returns:

this = conj(a);

Minus

public Z Minus(Z a)

Computes unary minus of a Z.

Parameters:

a - a Z

Returns:

this = -a;

Plus

public Z Plus(Z a,
              Z b)

Computes the sum of two Z's.

Parameters:

a - a Z

b - a Z

Returns:

this = a + b

Minus

public Z Minus(Z a,
               Z b)

Computes the difference of two Z's.

Parameters:

a - a Z

b - a Z

Returns:

this = a - b

Times

public Z Times(Z a,
               Z b)

Computes the product of two Z's.

Parameters:

a - a Z

b - a Z

Returns:

this = ab

Times

public Z Times(double a,
               Z b)

Computes the product of a double and a Z.

Parameters:

a - a double

b - a Z

Returns:

this = ab

Div

public Z Div(Z a,
             Z b)
      throws JampackException

Computes the quotient of two Z's. Throws a JampackException if the denominator is zero.

Parameters:

a - a Z

b - a Z

Returns:

this = a/b

Throws:

JampackException - Thrown if b is zero.

Div

public Z Div(Z a,
             double b)
      throws JampackException

Computes the quotient of a Z and a double. Throws a JampackException if the denominator is zero.

Parameters:

a - a Z

b - a double

Returns:

this = a/b

Throws:

JampackException - Thrown if b is zero.

Sqrt

public Z Sqrt(Z a)

Computes the principal value of the square root of a Z.

Parameters:

a - a Z

this - = sqrt(a)