filledarrayBy

Create a filled array according to a provided callback function.

Installation

npm install @stdlib/array-filled-by

Usage

var filledarrayBy = require( '@stdlib/array-filled-by' );

filledarrayBy( [dtype] )

Creates a filled array having a specified data type dtype.

var arr = filledarrayBy();
// returns <Float64Array>

The function recognizes the following data types:

• float64: double-precision floating-point numbers (IEEE 754)
• float32: single-precision floating-point numbers (IEEE 754)
• complex128: double-precision complex floating-point numbers
• complex64: single-precision complex floating-point numbers
• int32: 32-bit two's complement signed integers
• uint32: 32-bit unsigned integers
• int16: 16-bit two's complement signed integers
• uint16: 16-bit unsigned integers
• int8: 8-bit two's complement signed integers
• uint8: 8-bit unsigned integers
• uint8c: 8-bit unsigned integers clamped to 0-255
• generic: generic JavaScript values

By default, the output array data type is float64 (i.e., a typed array). To specify an alternative data type, provide a dtype argument.

var arr = filledarrayBy( 'int32' );
// returns <Int32Array>

filledarrayBy( length[, dtype], clbk[, thisArg] )

Returns a filled array according to a provided callback function and having a specified length.

function constant() {
    return 1.0;
}

var arr1 = filledarrayBy( 5, constant );
// returns <Float64Array>[ 1.0, 1.0, 1.0, 1.0, 1.0 ]

var arr2 = filledarrayBy( 5, 'uint8', constant );
// returns <Uint8Array>[ 1, 1, 1, 1, 1 ]

filledarrayBy( array[, dtype], clbk[, thisArg] )

Creates a filled array from another array (or array-like object) according to a provided callback function.

var arr0 = {
    '0': 0.5,
    '1': 0.5,
    '2': 0.5,
    'length': 3
};

function clbk1() {
    return 1.0;
}
var arr1 = filledarrayBy( arr0, clbk1 );
// returns <Float64Array>[ 1.0, 1.0, 1.0 ]

function clbk2() {
    return 2.0;
}
var arr2 = filledarrayBy( arr1, clbk2 );
// returns <Float64Array>[ 2.0, 2.0, 2.0 ]

function clbk3() {
    return 3.0;
}
var arr3 = filledarrayBy( arr1, 'int32', clbk3 );
// returns <Int32Array>[ 3, 3, 3 ]

filledarrayBy( iterable[, dtype], clbk[, thisArg] )

Creates a filled array from an iterable according to a provided callback function.

var iterConstant = require( '@stdlib/iter-constant' );

function clbk() {
    return 1.0;
}

var it = iterConstant( 3.0, {
    'iter': 3
});

var arr1 = filledarrayBy( it, clbk );
// returns <Float64Array>[ 1.0, 1.0, 1.0 ]

var arr2 = filledarrayBy( it, 'float32', clbk );
// returns <Float32Array>[ 1.0, 1.0, 1.0 ]

filledarrayBy( buffer[, byteOffset[, length]][, dtype], clbk[, thisArg] )

Returns a filled typed array view of an ArrayBuffer according to a provided callback function.

var ArrayBuffer = require( '@stdlib/array-buffer' );

function clbk() {
    return 1.0;
}

var buf = new ArrayBuffer( 32 );
var arr = filledarrayBy( buf, clbk );
// returns <Float64Array>[ 1.0, 1.0, 1.0, 1.0 ]

buf = new ArrayBuffer( 32 );
arr = filledarrayBy( buf, 'float32', clbk );
// returns <Float32Array>[ 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0 ]

buf = new ArrayBuffer( 32 );
arr = filledarrayBy( buf, 16, clbk );
// returns <Float64Array>[ 1.0, 1.0 ]

buf = new ArrayBuffer( 32 );
arr = filledarrayBy( buf, 16, 'float32', clbk );
// returns <Float32Array>[ 1.0, 1.0, 1.0, 1.0 ]

buf = new ArrayBuffer( 32 );
arr = filledarrayBy( buf, 16, 1, clbk );
// returns <Float64Array>[ 1.0 ]

buf = new ArrayBuffer( 32 );
arr = filledarrayBy( buf, 10, 4, 'int16', clbk );
// returns <Int16Array>[ 1, 1, 1, 1 ]

Notes

• Creating a generic array from an ArrayBuffer is not supported.

• A callback function is provided a single argument:

  • index: the current array index.

Examples

var discreteUniform = require( '@stdlib/random-base-discrete-uniform' ).factory;
var dtypes = require( '@stdlib/array-typed-real-dtypes' );
var filledarrayBy = require( '@stdlib/array-filled-by' );

// Create a pseudorandom number generator:
var rand = discreteUniform( 0, 100 );

// Get a list of array data types:
var dt = dtypes();

// Generate filled arrays...
var arr;
var i;
for ( i = 0; i < dt.length; i++ ) {
    arr = filledarrayBy( 10, dt[ i ], rand );
    console.log( arr );
}

See Also

• @stdlib/array-filled: create a filled array.
• @stdlib/array-typed: create a typed array.

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

Community

License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.