Package de.gsi.math

Class ArrayMath

java.lang.Object

de.gsi.math.ArrayMath

public final class ArrayMath
extends java.lang.Object

some double array convenience methods

Author:

rstein

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ArrayMath.FilterType

Constructor Summary

Constructors

Constructor	Description
ArrayMath()

Method Summary

Modifier and Type	Method	Description
static double[]	add(double[] in, double add)
static double[]	add(double[] in, double[] add)
static double[]	addInPlace(double[] in, double value)
static double[]	addInPlace(double[] in, double[] value)
static double[]	calculateFilterParameters(double cutoffFraction, ArrayMath.FilterType filterType, double rippleP, double numberOfPoles, int iteration)	calculate 2nd-order filter with Butterworth (rippleP=0) or Chebychev filter response (rippleP>0) N.B.
static double[]	decibel(double[] in)
static double[]	decibelInPlace(double[] in)
static double[]	divide(double[] in, double divisor)
static double[]	divide(double[] in, double[] divisor)
static double[]	divideInPlace(double[] in, double divisor)
static double[]	divideInPlace(double[] in, double[] divisor)
static double[]	filterSignal(double[] signal, double cutoffFraction, double filterOrder, ArrayMath.FilterType filterType, double ripplePercent)	filter from: "The Scientist and Engineer's Guide to DSP" Chapter 20
static double[]	multiply(double[] in, double multiplicator)
static double[]	multiply(double[] in, double[] multiplicator)
static double[]	multiplyInPlace(double[] in, double multiplicator)
static double[]	multiplyInPlace(double[] in, double[] multiplicator)
static double[]	sqr(double[] in)
static double[]	sqrInPlace(double[] in)
static double[]	sqrt(double[] in)
static double[]	sqrtInPlace(double[] in)
static double[]	subtract(double[] in, double value)
static double[]	subtract(double[] in, double[] value)
static double[]	subtractInPlace(double[] in, double value)
static double[]	subtractInPlace(double[] in, double[] value)
static double[]	tenLog10(double[] in)
static double[]	tenLog10InPlace(double[] in)

Methods inherited from class java.lang.Object

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

Constructor Detail

ArrayMath

public ArrayMath()

Method Detail

add

public static double[] add(double[] in,
                           double add)

add

public static double[] add(double[] in,
                           double[] add)

addInPlace

public static double[] addInPlace(double[] in,
                                  double value)

addInPlace

public static double[] addInPlace(double[] in,
                                  double[] value)

calculateFilterParameters

public static double[] calculateFilterParameters(double cutoffFraction,
                                                 ArrayMath.FilterType filterType,
                                                 double rippleP,
                                                 double numberOfPoles,
                                                 int iteration)

calculate 2nd-order filter with Butterworth (rippleP=0) or Chebychev filter response (rippleP>0) N.B. numerically validated against data set examples in Table 20-6 http://www.dspguide.com/ch20/4.htm

Parameters:

cutoffFraction - fractional cut-off

filterType - LOW_PASS or HIGH_PASS

rippleP - >0 -> Chebychev design-ripple in percent in the pass-band

numberOfPoles - number of poles (if combined with 2*n filter stages)

iteration - (whether this is the i-th filter in the chain)

Returns:

array of [A0, A1, A2, B1, B2]

decibel

public static double[] decibel(double[] in)

decibelInPlace

public static double[] decibelInPlace(double[] in)

divide

public static double[] divide(double[] in,
                              double divisor)

divide

public static double[] divide(double[] in,
                              double[] divisor)

divideInPlace

public static double[] divideInPlace(double[] in,
                                     double divisor)

divideInPlace

public static double[] divideInPlace(double[] in,
                                     double[] divisor)

filterSignal

public static double[] filterSignal(double[] signal,
                                    double cutoffFraction,
                                    double filterOrder,
                                    ArrayMath.FilterType filterType,
                                    double ripplePercent)

filter from: "The Scientist and Engineer's Guide to DSP" Chapter 20

Parameters:

signal - input signal

cutoffFraction - cutoffFreq must be smaller than half the samplerate

filterOrder - can be between 2 and 20

filterType - 0: lowPass 1: highPass

ripplePercent - ripplePercent is amount of ripple in Chebyshev filter (0-29) (ripplePercent == 0 -> Butterworth)

Returns:

filtered output signal

multiply

public static double[] multiply(double[] in,
                                double multiplicator)

multiply

public static double[] multiply(double[] in,
                                double[] multiplicator)

multiplyInPlace

public static double[] multiplyInPlace(double[] in,
                                       double multiplicator)

multiplyInPlace

public static double[] multiplyInPlace(double[] in,
                                       double[] multiplicator)

sqr

public static double[] sqr(double[] in)

sqrInPlace

public static double[] sqrInPlace(double[] in)

sqrt

public static double[] sqrt(double[] in)

sqrtInPlace

public static double[] sqrtInPlace(double[] in)

subtract

public static double[] subtract(double[] in,
                                double value)

subtract

public static double[] subtract(double[] in,
                                double[] value)

subtractInPlace

public static double[] subtractInPlace(double[] in,
                                       double value)

subtractInPlace

public static double[] subtractInPlace(double[] in,
                                       double[] value)

tenLog10

public static double[] tenLog10(double[] in)

tenLog10InPlace

public static double[] tenLog10InPlace(double[] in)