sliceTo

Usage

var sliceTo = require( '@stdlib/ndarray/slice-to' );

sliceTo( x, ...stop[, options] )

Returns a read-only 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 y = sliceTo( x, 2, null );
// 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) or ending indices (exclusive) as separate arguments. Each index must be either null, undefined, or an integer. A value of null or undefined 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.
• options: function options.

The function supports two (mutually exclusive) means for providing index arguments:

1. providing a single array of index arguments.
2. providing index arguments as separate arguments.

The following example demonstrates each invocation style returning equivalent results.

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 ] ]

// 1. Using an array of index arguments:
var y = sliceTo( x, [ 2, null ] );
// returns <ndarray>

sh = y.shape;
// returns [ 2, 2 ]

arr = ndarray2array( y );
// returns [ [ 1.0, 2.0 ], [ 3.0, 4.0 ] ]

// 2. Providing separate arguments:
y = sliceTo( x, 2, null );
// returns <ndarray>

sh = y.shape;
// returns [ 2, 2 ]

arr = ndarray2array( y );
// returns [ [ 1.0, 2.0 ], [ 3.0, 4.0 ] ]

The function supports the following options:

• strict: boolean indicating whether to enforce strict bounds checking.

By default, the function throws an error when provided an index argument which exceeds array bounds. To return an empty array when an index exceeds array bounds, set the strict option to false.

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 y = sliceTo( x, 2, -20, {
    'strict': false
});
// returns <ndarray>

sh = y.shape;
// returns [ 2, 0 ]

arr = ndarray2array( y );
// returns []