time-to-botec/squiggle/node_modules/@stdlib/ndarray/base/assert/is-single-segment-compatible/README.md

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@license Apache-2.0
Copyright (c) 2018 The Stdlib Authors.
Licensed under the Apache License, Version 2.0 (the "License");
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# isSingleSegmentCompatible
> Determine if an array is compatible with a single memory segment.
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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.
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## Usage
```javascript
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.
```javascript
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
```
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## Examples
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```javascript
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 );
}
```
</section>
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