time-to-botec/squiggle/node_modules/@stdlib/math/iter/special/log/README.md

iterLog

Create an iterator which iteratively computes the base b logarithm.

Usage

var iterLog = require( '@stdlib/math/iter/special/log' );

iterLog( x, b )

Returns an iterator which iteratively computes the base b logarithm of x.

var array2iterator = require( '@stdlib/array/to-iterator' );

var x = array2iterator( [ 2.0, 2.0, 10.0 ] );
var y = array2iterator( [ 2.0, 6.0, 2.0 ] );

var it = iterLog( x, y );
// returns <Object>

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

r = it.next().value;
// returns ~0.3869

r = it.next().value;
// returns ~3.3219

// ...

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.

If provided a numeric value as an iterator argument, the value is broadcast as an infinite iterator which always returns the provided value.

var array2iterator = require( '@stdlib/array/to-iterator' );

var x = array2iterator( [ 2.0, 6.0 ] );

var it = iterLog( x, 2.0 );
// returns <Object>

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

v = it.next().value;
// returns ~2.58496

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

Notes

• For negative b or x iterated values, the returned iterator returns NaN.
• If an iterated value is non-numeric (including NaN), the returned iterator returns NaN. If non-numeric iterated values are possible, you are advised to provide an iterator which type checks and handles non-numeric values accordingly.
• The length of the returned iterator is equal to the length of the shortest provided iterator. In other words, the returned iterator ends once one of the provided iterators ends.
• If an environment supports Symbol.iterator and a provided iterator is iterable, the returned iterator is iterable.

Examples

var uniform = require( '@stdlib/random/iter/uniform' );
var iterLog = require( '@stdlib/math/iter/special/log' );

// Create seeded iterators for generating pseudorandom numbers:
var x = uniform( 0.0, 100.0, {
    'seed': 1234,
    'iter': 10
});

var y = uniform( 0.0, 10.0, {
    'seed': 4567,
    'iter': 10
});

// Create an iterator which consumes the pseudorandom number iterators:
var it = iterLog( x, y );

// Perform manual iteration...
var r;
while ( true ) {
    r = it.next();
    if ( r.done ) {
        break;
    }
    console.log( r.value );
}