jcuda.jcublas
Class JCuComplex

java.lang.Object
  jcuda.jcublas.JCuComplex

public class JCuComplex
extends Object

Java port of the CUBLAS complex number structure

Field Summary

float	x The real part of the complex number
float	y The imaginary part of the complex number

Method Summary

static float	cuCabs(JCuComplex x) Returns the absolute value of the given complex number Original comment: This implementation guards against intermediate underflow and overflow by scaling.
static JCuComplex	cuCadd(JCuComplex x, JCuComplex y) Returns a new complex number that is the sum of the given complex numbers
static JCuComplex	cuCdiv(JCuComplex x, JCuComplex y) Returns the quotient of the given complex numbers. Original comment: This implementation guards against intermediate underflow and overflow by scaling.
static float	cuCimag(JCuComplex x) Returns the imaginary part of the given complex number
static JCuComplex	cuCmplx(float r, float i) Creates a new complex number consisting of the given real and imaginary part
static JCuComplex	cuCmul(JCuComplex x, JCuComplex y) Returns the product of the given complex numbers. Original comment: This implementation could suffer from intermediate overflow even though the final result would be in range.
static JCuComplex	cuConj(JCuComplex x) Returns the complex conjugate of the given complex number
static float	cuCreal(JCuComplex x) Returns the real part of the given complex number
String	toString() Returns a String representation of this complex number

Methods inherited from class java.lang.Object

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

Field Detail

x

public float x

The real part of the complex number

y

public float y

The imaginary part of the complex number

Method Detail

cuCreal

public static float cuCreal(JCuComplex x)

Returns the real part of the given complex number

Parameters:

x - The complex number whose real part should be returned

Returns:

The real part of the given complex number

cuCimag

public static float cuCimag(JCuComplex x)

Returns the imaginary part of the given complex number

Parameters:

x - The complex number whose imaginary part should be returned

Returns:

The imaginary part of the given complex number

cuCmplx

public static JCuComplex cuCmplx(float r,
                                 float i)

Creates a new complex number consisting of the given real and imaginary part

Parameters:

r - The real part of the complex number

i - The imaginary part of the complex number

Returns:

A complex number with the given real and imaginary part

cuConj

public static JCuComplex cuConj(JCuComplex x)

Returns the complex conjugate of the given complex number

Parameters:

x - The complex number whose complex conjugate should be returned

Returns:

The complex conjugate of the given complex number

cuCadd

public static JCuComplex cuCadd(JCuComplex x,
                                JCuComplex y)

Returns a new complex number that is the sum of the given complex numbers

Parameters:

x - The first addend

y - The second addend

Returns:

The sum of the given addends

cuCmul

public static JCuComplex cuCmul(JCuComplex x,
                                JCuComplex y)

Returns the product of the given complex numbers.

Original comment:

This implementation could suffer from intermediate overflow even though the final result would be in range. However, various implementations do not guard against this (presumably to avoid losing performance), so we don't do it either to stay competitive.

Parameters:

x - The first factor

y - The second factor

Returns:

The product of the given factors

cuCdiv

public static JCuComplex cuCdiv(JCuComplex x,
                                JCuComplex y)

Returns the quotient of the given complex numbers.

Original comment:

This implementation guards against intermediate underflow and overflow by scaling. Such guarded implementations are usually the default for complex library implementations, with some also offering an unguarded, faster version.

Parameters:

x - The dividend

y - The divisor

Returns:

The quotient of the given complex numbers

cuCabs

public static float cuCabs(JCuComplex x)

Returns the absolute value of the given complex number

Original comment:

This implementation guards against intermediate underflow and overflow by scaling. Otherwise the we'd lose half the exponent range. There are various ways of doing guarded computation. For now chose the simplest and fastest solution, however this may suffer from inaccuracies if sqrt and division are not IEEE compliant.

Parameters:

x - The complex number whose absolute value should be returned

Returns:

The absolute value of the given complex number

toString

public String toString()

Returns a String representation of this complex number

Overrides:

toString in class Object

Returns:

A String representation of this complex number