com.jsyn.unitgen

Class FilterTwoPoles

java.lang.Object

com.jsyn.unitgen.UnitGenerator

com.jsyn.unitgen.UnitFilter

com.jsyn.unitgen.FilterTwoPoles

All Implemented Interfaces:

UnitSink, UnitSource

public class FilterTwoPoles
extends UnitFilter

Second Order, Two Pole filter using the following formula:

 y(n) = A0*x(n) - B1*y(n-1) - B2*y(n-2)
 

where y(n) is Output, x(n) is Input, and y(n-1) is a delayed copy of the output. This filter is a recursive IIR or Infinite Impulse Response filter. it can be unstable depending on the values of the coefficients. A thorough description of the digital filter theory needed to fully describe this filter is beyond the scope of this document. Calculating coefficients is non-intuitive; the interested user is referred to one of the standard texts on filter theory (e.g., Moore, "Elements of Computer Music", section 2.4).

Field Summary

Fields

Modifier and Type	Field and Description
UnitVariablePort	a0
UnitVariablePort	b1
UnitVariablePort	b2

Fields inherited from class com.jsyn.unitgen.UnitFilter

input, output

Fields inherited from class com.jsyn.unitgen.UnitGenerator

FALSE, TRUE

Constructor Summary

Constructors

Constructor and Description
FilterTwoPoles()

Method Summary

Methods

Modifier and Type	Method and Description
void	generate(int start, int limit) Perform essential synthesis function.

Methods inherited from class com.jsyn.unitgen.UnitFilter

getInput, getOutput

Methods inherited from class com.jsyn.unitgen.UnitGenerator

addPort, addPort, convertHalfLifeToMultiplier, flattenOutputs, generate, getCircuit, getFramePeriod, getFrameRate, getPortByName, getPorts, getSynthesisEngine, getSynthesizer, getTopUnit, getUnitGenerator, isEnabled, pullData, setCircuit, setEnabled, setFrameRate, setPort, setSynthesisEngine, start, start, stop, stop

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.jsyn.unitgen.UnitSink

getUnitGenerator, start, start, stop, stop

Methods inherited from interface com.jsyn.unitgen.UnitSource

getUnitGenerator

Field Detail

a0

public UnitVariablePort a0

b1

public UnitVariablePort b1

b2

public UnitVariablePort b2

Constructor Detail

FilterTwoPoles

public FilterTwoPoles()

Method Detail

generate

public void generate(int start,
            int limit)

Description copied from class: UnitGenerator

Perform essential synthesis function.

Specified by:

generate in class UnitGenerator

Parameters:

start - offset into port buffers

limit - limit offset into port buffers for loop