isSingleSegmentCompatible

Determine if an array is compatible with a single memory segment.

An array is compatible with a single memory segment when an array view spans only the elements belonging to the array. When an array is compatible with a single memory segment, array data can be stored as a single block of memory.

Installation

npm install @stdlib/ndarray-base-assert-is-single-segment-compatible

Usage

var isSingleSegmentCompatible = require( '@stdlib/ndarray-base-assert-is-single-segment-compatible' );

isSingleSegmentCompatible( shape, strides, offset )

Returns a boolean indicating if an array is compatible with a single memory segment.

var shape = [ 2, 2 ];
var strides = [ 2, 1 ];
var offset = 25;

var bool = isSingleSegmentCompatible( shape, strides, offset );
// returns true

shape = [ 10 ];
strides = [ 3 ]; // every third memory element
offset = 0;

bool = isSingleSegmentCompatible( shape, strides, offset );
// returns false

Examples

var discreteUniform = require( '@stdlib/random-base-discrete-uniform' );
var shape2strides = require( '@stdlib/ndarray-base-shape2strides' );
var strides2offset = require( '@stdlib/ndarray-base-strides2offset' );
var randu = require( '@stdlib/random-base-randu' );
var isSingleSegmentCompatible = require( '@stdlib/ndarray-base-assert-is-single-segment-compatible' );

var strides;
var offset;
var shape;
var bool;
var i;
var j;

shape = [ 0, 0, 0 ];

for ( i = 0; i < 100; i++ ) {
    // Generate a random array shape:
    shape[ 0 ] = discreteUniform( 1, 10 );
    shape[ 1 ] = discreteUniform( 1, 10 );
    shape[ 2 ] = discreteUniform( 1, 10 );

    // Generate strides:
    if ( randu() < 0.5 ) {
        strides = shape2strides( shape, 'row-major' );
    } else {
        strides = shape2strides( shape, 'column-major' );
    }
    j = discreteUniform( 0, shape.length-1 );
    strides[ j ] *= ( randu() < 0.5 ) ? -1 : 1;

    strides[ 0 ] *= discreteUniform( 1, 4 ); // if scaled by 1, then single segment

    // Compute the index offset:
    offset = strides2offset( shape, strides );

    // Determine if the array is compatible with a single memory segment:
    bool = isSingleSegmentCompatible( shape, strides, offset );
    console.log( 'Shape: %s. Strides: %s. Offset: %d. Single segment compatible: %s.', shape.join( 'x' ), strides.join( ',' ), offset, bool );
}

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.