Minim
core | ugens | analysis
 

Frequency

ofHertz

Description

Construct a Frequency that represents the provided Hertz.

Signature

Frequency ofHertz(float hz)

Parameters

hz — float: the Hz for this Frequency (440 is A4, for instance)

Returns

a new Frequency object

Related

Frequency

Example

/* frequencyExample<br/>
   is an example of using the Frequency class to easily turn keyboard input 
   into the frequency of an Oscil. Simply type on the home row to change 
   the pitch of the tone. 
   <p>
   For more information about Minim and additional features, 
   visit http://code.compartmental.net/minim/
*/

// import everything necessary to make sound.
import ddf.minim.*;
import ddf.minim.ugens.*;

// create all of the variables that will need to be accessed in
// more than one methods (setup(), draw(), stop()).
Minim minim;
AudioOutput out;

Oscil      wave;
// keep track of the current Frequency so we can display it
Frequency  currentFreq;

// setup is run once at the beginning
void setup()
{
  // initialize the drawing window
  size(512, 200);
  
  // initialize the minim and out objects
  minim = new Minim(this);
  out   = minim.getLineOut();

  currentFreq = Frequency.ofPitch( "A4" );
  wave = new Oscil( currentFreq, 0.6f, Waves.TRIANGLE );
  
  wave.patch( out );
}

// draw is run many times
void draw()
{
  // erase the window to brown
  background( 64, 32, 0 );
  // draw using a beige stroke
  stroke( 255, 238, 192 );
  
  text( "Current Frequency in Hertz: " + currentFreq.asHz(), 5, 15 );
  text( "Current Frequency as MIDI note: " + currentFreq.asMidiNote(), 5, 30 );
  
  // draw the waveforms
  for( int i = 0; i < out.bufferSize() - 1; i++ )
  {
    // find the x position of each buffer value
    float x1  =  map( i, 0, out.bufferSize(), 0, width );
    float x2  =  map( i+1, 0, out.bufferSize(), 0, width );
    // draw a line from one buffer position to the next for both channels
    line( x1, 50 + out.left.get(i)*50, x2, 50 + out.left.get(i+1)*50);
    line( x1, 150 + out.right.get(i)*50, x2, 150 + out.right.get(i+1)*50);
  }  
}

// change the midi note when pressing keys on the keyboard
// we set midiNoteIn directly with the setMidiNoteIn method
// but you could also use a Line to lerp to the next note
// by patching it to midiNoteIn.
void keyPressed()
{
  if ( key == 'a' ) currentFreq = Frequency.ofPitch( "A4" );
  if ( key == 's' ) currentFreq = Frequency.ofPitch( "B4" );
  if ( key == 'd' ) currentFreq = Frequency.ofPitch( "C#5" );
  if ( key == 'f' ) currentFreq = Frequency.ofPitch( "D5" );
  if ( key == 'g' ) currentFreq = Frequency.ofPitch( "E5" );
  if ( key == 'h' ) currentFreq = Frequency.ofPitch( "F#5" );
  if ( key == 'j' ) currentFreq = Frequency.ofPitch( "G#5" );
  if ( key == 'k' ) currentFreq = Frequency.ofPitch( "A5" );
  if ( key == 'l' ) currentFreq = Frequency.ofPitch( "B5" );
  if ( key == ';' ) currentFreq = Frequency.ofPitch( "C#6" );
  if ( key == '\'') currentFreq = Frequency.ofPitch( "E6" );
  
  // note that there are two other static methods for constructing Frequency objects
  // currentFreq = Frequency.ofHertz( 440 );
  // currentFreq = Frequency.ofMidiNote( 69 ); 
  
  wave.setFrequency( currentFreq );
}

Usage

Web & Application