Float64Array in little-endian byte order.
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> Typed array constructor which returns a typed array representing an array of double-precision floating-point numbers in little-endian byte order.
In contrast to the [Float64Array][@stdlib/array/float64] typed array constructor which stores values according to the host platform byte order, the Float64ArrayLE constructor always accesses elements in little-endian byte order. Such enforcement can be particularly advantageous when working with memory buffers which do not necessarily follow host platform byte order, such as [WebAssembly memory][@stdlib/wasm/memory].
``bash`
npm install @stdlib/array-little-endian-float64
`javascript`
var Float64ArrayLE = require( '@stdlib/array-little-endian-float64' );
#### Float64ArrayLE()
A typed array constructor which returns a typed array representing an array of double-precision floating-point numbers in little-endian byte order.
`javascript`
var arr = new Float64ArrayLE();
// returns
#### Float64ArrayLE( length )
Returns a typed array having a specified length.
`javascript`
var arr = new Float64ArrayLE( 5 );
// returns
#### Float64ArrayLE( typedarray )
Creates a typed array from another typed array.
`javascript
var Float32Array = require( '@stdlib/array-float32' );
var arr1 = new Float32Array( [ 0.5, 0.5, 0.5 ] );
var arr2 = new Float64ArrayLE( arr1 );
// returns
var v = arr2.get( 0 );
// returns 0.5
`
#### Float64ArrayLE( obj )
Creates a typed array from an array-like object or iterable.
`javascript
var arr = new Float64ArrayLE( [ 0.5, 0.5, 0.5 ] );
// returns
var v = arr.get( 0 );
// returns 0.5
`
#### Float64ArrayLE( buffer\[, byteOffset\[, length]] )
Returns a typed array view of an [ArrayBuffer][@stdlib/array/buffer].
`javascript
var ArrayBuffer = require( '@stdlib/array-buffer' );
var buf = new ArrayBuffer( 32 );
var arr = new Float64ArrayLE( buf, 0, 4 );
// returns
`
*
#### Float64ArrayLE.BYTES_PER_ELEMENT
Number of bytes per view element.
`javascript`
var nbytes = Float64ArrayLE.BYTES_PER_ELEMENT;
// returns 8
#### Float64ArrayLE.name
Typed array constructor name.
`javascript`
var str = Float64ArrayLE.name;
// returns 'Float64ArrayLE'
#### Float64ArrayLE.prototype.buffer
Read-only property which returns the [ArrayBuffer][@stdlib/array/buffer] referenced by the typed array.
`javascript`
var arr = new Float64ArrayLE( 5 );
var buf = arr.buffer;
// returns
#### Float64ArrayLE.prototype.byteLength
Read-only property which returns the length (in bytes) of the typed array.
`javascript`
var arr = new Float64ArrayLE( 5 );
var byteLength = arr.byteLength;
// returns 40
#### Float64ArrayLE.prototype.byteOffset
Read-only property which returns the offset (in bytes) of the typed array from the start of its [ArrayBuffer][@stdlib/array/buffer].
`javascript`
var arr = new Float64ArrayLE( 5 );
var byteOffset = arr.byteOffset;
// returns 0
#### Float64ArrayLE.prototype.BYTES_PER_ELEMENT
Number of bytes per view element.
`javascript`
var arr = new Float64ArrayLE( 5 );
var nbytes = arr.BYTES_PER_ELEMENT;
// returns 8
#### Float64ArrayLE.prototype.length
Read-only property which returns the number of view elements.
`javascript`
var arr = new Float64ArrayLE( 5 );
var len = arr.length;
// returns 5
*
#### Float64ArrayLE.from( src\[, map\[, thisArg]] )
Creates a new typed array from an array-like object or an iterable.
`javascript
var arr = Float64ArrayLE.from( [ 1.0, -1.0 ] );
// returns
var v = arr.get( 0 );
// returns 1.0
`
To invoke a function for each src value, provide a callback function.
`javascript
function mapFcn( v ) {
return v * 2.0;
}
var arr = Float64ArrayLE.from( [ 1.0, -1.0 ], mapFcn );
// returns
var v = arr.get( 0 );
// returns 2.0
`
A callback function is provided two arguments:
- value: source value.
- index: source index.
To set the callback execution context, provide a thisArg.
`javascript
function mapFcn( v ) {
this.count += 1;
return v * 2.0;
}
var ctx = {
'count': 0
};
var arr = Float64ArrayLE.from( [ 1.0, -1.0 ], mapFcn, ctx );
// returns
var v = arr.get( 0 );
// returns 2.0
var n = ctx.count;
// returns 2
`
#### Float64ArrayLE.of( element0\[, element1\[, ...elementN]] )
Creates a new typed array from a variable number of arguments.
`javascript
var arr = Float64ArrayLE.of( 1.0, -1.0 );
// returns
var v = arr.get( 0 );
// returns 1.0
`
#### Float64ArrayLE.prototype.get( i )
Returns an array element located at a nonnegative integer position (index) i.
`javascript
var arr = new Float64ArrayLE( 10 );
// Set the first element:
arr.set( 1.0, 0 );
// Get the first element:
var v = arr.get( 0 );
// returns 1.0
`
If provided an out-of-bounds index, the method returns undefined.
`javascript
var arr = new Float64ArrayLE( 10 );
var v = arr.get( 100 );
// returns undefined
`
#### Float64ArrayLE.prototype.set( arr\[, offset] )
Sets array elements.
`javascript
var arr = new Float64ArrayLE( [ 1.0, 2.0, 3.0 ] );
// returns
var v = arr.get( 0 );
// returns 1.0
v = arr.get( 1 );
// returns 2.0
// Set the first two array elements:
arr.set( [ 4.0, 5.0 ] );
v = arr.get( 0 );
// returns 4.0
v = arr.get( 1 );
// returns 5.0
`
By default, the method starts writing values at the first array index. To specify an alternative index, provide an index offset.
`javascript
var arr = new Float64ArrayLE( [ 1.0, 2.0, 3.0 ] );
// returns
// Set the last two array elements:
arr.set( [ 4.0, 5.0 ], 1 );
var v = arr.get( 1 );
// returns 4.0
v = arr.get( 2 );
// returns 5.0
`
A few notes:
- If i is out-of-bounds, the method throws an error.i
- If a target array cannot accommodate all values (i.e., the length of source array plus exceeds the target array length), the method throws an error.ArrayBuffer
- If provided a typed array which shares an [][@stdlib/array/buffer] with the target array, the method will intelligently copy the source range to the destination range.
#### Float64ArrayLE.prototype.toString()
Serializes an array as a string.
`javascript
var arr = new Float64ArrayLE( [ 1.0, 2.0, 3.0 ] );
var str = arr.toString();
// returns '1,2,3'
`
*
- While a Float64ArrayLE _strives_ to maintain (but does not guarantee) consistency with [typed arrays][@stdlib/array/typed], significant deviations from ECMAScript-defined [typed array][@stdlib/array/typed] behavior are as follows:
- The constructor does not require the new operator.X[i]
- Accessing array elements using bracket syntax (e.g., ) is not supported. Instead, one must use the .get() method.
*
`javascript
var Float64Array = require( '@stdlib/array-float64' );
var logEach = require( '@stdlib/console-log-each' );
var Float64ArrayLE = require( '@stdlib/array-little-endian-float64' );
// Create a typed array by specifying a length:
var out = new Float64ArrayLE( 3 );
logEach( '%s', out );
// Create a typed array from an array:
var arr = [ 1.0, -1.0, -3.14, 3.14, 0.5, 0.5 ];
out = new Float64ArrayLE( arr );
logEach( '%s', out );
// Create a typed array from an array buffer:
arr = new Float64Array( [ 1.0, -1.0, -3.14, 3.14, 0.5, 0.5 ] ); // host byte order
out = new Float64ArrayLE( arr.buffer );
logEach( '%s', out );
// Create a typed array from an array buffer view:
arr = new Float64Array( [ 1.0, -1.0, -3.14, 3.14, 0.5, 0.5 ] ); // host byte order
out = new Float64ArrayLE( arr.buffer, 8, 2 );
logEach( '%s', out );
`
*
- [@stdlib/array-fixed-endian-float64][@stdlib/array/fixed-endian-float64]: Float64Array having a specified byte order.
- [@stdlib/array-float64][@stdlib/array/float64]: Float64Array.
- [@stdlib/array-little-endian-float32][@stdlib/array/little-endian-float32]: Float32Array in little-endian byte order.
*
This package is part of [stdlib][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][stdlib], see the main project [repository][stdlib].
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