iterCosineWave

Usage

var iterCosineWave = require( '@stdlib/simulate/iter/cosine-wave' );

iterCosineWave( [options] )

Returns an iterator which generates a cosine wave.

var it = iterCosineWave();
// returns <Object>

var v = it.next().value;
// returns <number>

v = it.next().value;
// returns <number>

v = it.next().value;
// returns <number>

// ...

The returned iterator protocol-compliant object has the following properties:

• next: function which returns an iterator protocol-compliant object containing the next iterated value (if one exists) assigned to a value property and a done property having a boolean value indicating whether the iterator is finished.
• return: function which closes an iterator and returns a single (optional) argument in an iterator protocol-compliant object.

The function supports the following options:

• period: period (i.e., the number of iterations before a cosine wave repeats). Default: 10.
• amplitude: peak amplitude. Default: 1.0.
• offset: phase offset (in units of iterations; zero-based). A negative offset translates a waveform to the left. A positive offset translates a waveform to the right. Default: 0.
• iter: number of iterations. Default: 1e308.

By default, the function returns an iterator which generates a cosine wave that repeats every 10 iterations. To specify an alternative period, set the period option.

var opts = {
    'period': 4
};

var it = iterCosineWave( opts );
// returns <Object>

var v = it.next().value;
// returns 1.0

v = it.next().value;
// returns 0.0

v = it.next().value;
// returns -1.0

v = it.next().value;
// returns 0.0

v = it.next().value;
// returns 1.0

// ...

To adjust at what point the iterator begins in the waveform cycle, set the phase offset option. For example, to translate the waveform to the left,

var opts = {
    'period': 4,
    'offset': -1
};

var it = iterCosineWave( opts );
// returns <Object>

var v = it.next().value;
// returns 0.0

v = it.next().value;
// returns -1.0

v = it.next().value;
// returns 0.0

v = it.next().value;
// returns 1.0

v = it.next().value;
// returns 0.0

// ...

To translate the waveform to the right,

var opts = {
    'period': 4,
    'offset': 1
};

var it = iterCosineWave( opts );
// returns <Object>

var v = it.next().value;
// returns 0.0

v = it.next().value;
// returns 1.0

v = it.next().value;
// returns 0.0

v = it.next().value;
// returns -1.0

v = it.next().value;
// returns 0.0

// ...

By default, the function returns an infinite iterator (i.e., an iterator which never ends). To limit the number of iterations, set the iter option.

var opts = {
    'iter': 2
};
var it = iterCosineWave( opts );
// returns <Object>

var v = it.next().value;
// returns <number>

v = it.next().value;
// returns <number>

var bool = it.next().done;
// returns true