Package xal.tools.dsp

Class DigitalDifferentiator

java.lang.Object

xal.tools.dsp.AbstractDigitalFilter

xal.tools.dsp.LtiDigitalFilter

xal.tools.dsp.DigitalDifferentiator

public class DigitalDifferentiator
extends LtiDigitalFilter

Convenience class implementing a simple 1^st order digital differentiator. The response y_n of this filter to an input x_n is given by

y_n = x_n - x_n-1

Thus, the transfer function H(z) is given by

H(z) = 1 - z^-1

where z is the Z-transform variable.

The differentiator is initialized so that the initial input x_-1 is zero. Thus, the first output from this filter is the first input. This value may be changed with a call to LtiDigitalFilter.setInputCoefficient(int, double).

Author:

Christopher K. Allen

See Also:

• LtiDigitalFilter

Constructor Summary

Constructors

Constructor	Description
DigitalDifferentiator()	Create a new DigitalDifferentiator object with zero initial response.
DigitalDifferentiator(double dblVal)	Create a new DigitalDifferentiator object with the given initial response.

Method Summary

Modifier and Type	Method	Description
void	setInitialResponse(double dblVal)	Set the initial response of the differentiator to the given value.

Methods inherited from class xal.tools.dsp.LtiDigitalFilter

getInputCoefficient, getInputCoefficient, getOutputCoefficient, getOutputCoefficient, setInputCoefficient, setInputCoefficients, setOutputCoefficient, setOutputCoefficients, toString, transferFunction

Methods inherited from class xal.tools.dsp.AbstractDigitalFilter

getCoefficientCount, getOrder, getTimeIndex, reset, response, response

Methods inherited from class java.lang.Object

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

Constructor Details

DigitalDifferentiator

public DigitalDifferentiator()

Create a new DigitalDifferentiator object with zero initial response.

See Also:

• setInitialResponse(double)

DigitalDifferentiator

public DigitalDifferentiator(double dblVal)

Create a new DigitalDifferentiator object with the given initial response.

Parameters:

dblVal - initial response of the differentiator

Method Details

setInitialResponse

public void setInitialResponse(double dblVal)

Set the initial response of the differentiator to the given value. Note also the the filter is reset.

Parameters:

dblVal - initial response of the differentiator

See Also:

• AbstractDigitalFilter.reset()