One Pole Low Pass

Overview

Basic one pole low-pass filter serves as an important building block due to its utility in a vast number of applications including noise reduction, signal smoothing, and extracting relevant information from a signal. The 6dB/octave slope of the single pole filter is suitable for many non-critical use-cases and its simplicity makes it computationally efficient.

Include

#include <q/fx/lowpass.hpp>

Declaration

struct one_pole_lowpass
{
                     one_pole_lowpass(frequency f, float sps);

   float             operator()(float s);
   float             operator()() const;
   one_pole_lowpass& operator=(bool y);
   void              cutoff(frequency f, float sps);
};

Expressions

Notation

lp, a, b

Objects of type one_pole_lowpass.

f

Object of type frequency representing the cutoff frequency.

sps

Floating point value representing samples per second.

s

Input sample.

Constructor

Constructors and Assignment

Expression Semantics

one_pole_lowpass(f, sps)

Construct a one_pole_lowpass with specified cutoff frequency, f, and samples per second sps.

one_pole_lowpass(b)

Copy construct a one_pole_lowpass from b.

a = b

Assign b to a.

a = s

Set the latest result to s.
C++ brace initialization may also be used.
Expression Semantics Return Type

lp()

Return the latest result.

float

lp(s)

process the input sample, s.

float

Mutators

Expression Semantics Return Type

lp.cutoff(f, sps)

Set the cutoff frequency given frequency f, and samples per second sps.

void