@stdlib/ndarray-base-slice-to
v0.2.2
Published
Return a truncated view of an input ndarray.
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sliceTo
Return a truncated view of an input ndarray.
Installation
npm install @stdlib/ndarray-base-slice-to
Usage
var sliceTo = require( '@stdlib/ndarray-base-slice-to' );
sliceTo( x, stop, strict, writable )
Returns a truncated view of an input ndarray.
var ndarray = require( '@stdlib/ndarray-ctor' );
var ndarray2array = require( '@stdlib/ndarray-to-array' );
var buffer = [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ];
var shape = [ 3, 2 ];
var strides = [ 2, 1 ];
var offset = 0;
var x = ndarray( 'generic', buffer, shape, strides, offset, 'row-major' );
// returns <ndarray>
var sh = x.shape;
// returns [ 3, 2 ]
var arr = ndarray2array( x );
// returns [ [ 1.0, 2.0 ], [ 3.0, 4.0 ], [ 5.0, 6.0 ] ]
var s = [ 2, null ];
var y = sliceTo( x, s, false, false );
// returns <ndarray>
sh = y.shape;
// returns [ 2, 2 ]
arr = ndarray2array( y );
// returns [ [ 1.0, 2.0 ], [ 3.0, 4.0 ] ]
The function accepts the following arguments:
- x: input ndarray.
- stop: an array of ending indices (exclusive). Each element must be either
null
,undefined
, or an integer. A value ofnull
orundefined
indicates to include all elements along a corresponding dimension. A negative integer indicates to resolve an ending index relative to the last element along a corresponding dimension, with the last element having index-1
. - strict: boolean indicating whether to enforce strict bounds checking.
- writable: boolean indicating whether a returned ndarray should be writable.
Notes
- The
writable
parameter only applies to ndarray constructors supporting read-only instances.
Examples
var array = require( '@stdlib/ndarray-array' );
var ndarray2array = require( '@stdlib/ndarray-to-array' );
var zeroTo = require( '@stdlib/array-base-zero-to' );
var sliceTo = require( '@stdlib/ndarray-base-slice-to' );
// Create a linear ndarray buffer:
var buf = zeroTo( 27 );
// Create an ndarray:
var x = array( buf, {
'shape': [ 3, 3, 3 ]
});
// Get the first two rows of each matrix:
var y1 = sliceTo( x, [ null, 2, null ], false, false );
// returns <ndarray>
var a1 = ndarray2array( y1 );
// returns [ [ [ 0, 1, 2 ], [ 3, 4, 5 ] ], [ [ 9, 10, 11 ], [ 12, 13, 14 ] ], [ [ 18, 19, 20 ], [ 21, 22, 23 ] ] ]
// Get the first two rows and columns of each matrix:
var y2 = sliceTo( x, [ null, 2, 2 ], false, false );
// returns <ndarray>
var a2 = ndarray2array( y2 );
// returns [ [ [ 0, 1 ], [ 3, 4 ] ], [ [ 9, 10 ], [ 12, 13 ] ], [ [ 18, 19 ], [ 21, 22 ] ] ]
// Get the first two 2x2 matrices:
var y3 = sliceTo( x, [ 2, 2, 2 ], false, false );
// returns <ndarray>
var a3 = ndarray2array( y3 );
// returns [ [ [ 0, 1 ], [ 3, 4 ] ], [ [ 9, 10 ], [ 12, 13 ] ] ]
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.