Home   Information   Classes   Download   Usage   Mail List   Requirements   Tutorial

TwoZero Class Reference

STK two-zero filter class. More...

#include <TwoZero.h>

Inheritance diagram for TwoZero::

Filter Stk List of all members.

Public Methods

 TwoZero ()
 Default constructor creates a second-order pass-through filter.

 ~TwoZero ()
 Class destructor.

void clear (void)
 Clears the internal states of the filter.

void setB0 (MY_FLOAT b0)
 Set the b[0] coefficient value.

void setB1 (MY_FLOAT b1)
 Set the b[1] coefficient value.

void setB2 (MY_FLOAT b2)
 Set the b[2] coefficient value.

void setNotch (MY_FLOAT frequency, MY_FLOAT radius)
 Sets the filter coefficients for a "notch" at frequency (in Hz). More...

void setGain (MY_FLOAT theGain)
 Set the filter gain. More...

MY_FLOAT getGain (void) const
 Return the current filter gain.

MY_FLOAT lastOut (void) const
 Return the last computed output value.

MY_FLOAT tick (MY_FLOAT sample)
 Input one sample to the filter and return one output.

MY_FLOAT* tick (MY_FLOAT *vector, unsigned int vectorSize)
 Input vectorSize samples to the filter and return an equal number of outputs in vector.

Detailed Description

STK two-zero filter class.

This protected Filter subclass implements a two-zero digital filter. A method is provided for creating a "notch" in the frequency response while maintaining a constant filter gain.

by Perry R. Cook and Gary P. Scavone, 1995 - 2002.

Member Function Documentation

void TwoZero::setNotch ( MY_FLOAT frequency,
MY_FLOAT radius )
 

Sets the filter coefficients for a "notch" at frequency (in Hz).

This method determines the filter coefficients corresponding to two complex-conjugate zeros with the given frequency (in Hz) and radius from the z-plane origin. The coefficients are then normalized to produce a maximum filter gain of one (independent of the filter gain parameter). The resulting filter frequency response has a "notch" or anti-resonance at the given frequency. The closer the zeros are to the unit-circle (radius close to or equal to one), the narrower the resulting notch width.

void TwoZero::setGain ( MY_FLOAT theGain ) [virtual]
 

Set the filter gain.

The gain is applied at the filter input and does not affect the coefficient values. The default gain value is 1.0.

Reimplemented from Filter.

The documentation for this class was generated from the following file:
The Synthesis ToolKit in C++ (STK)
©1995-2002 Perry R. Cook and Gary P. Scavone. All Rights Reserved.