@stdlib/assert
Version:
Standard assertion utilities.
53 lines (45 loc) • 1.65 kB
TypeScript
/*
* @license Apache-2.0
*
* Copyright (c) 2021 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// TypeScript Version: 4.1
/// <reference types="@stdlib/types"/>
import { ndarray } from '@stdlib/types/ndarray';
/**
* Tests if a value is a centrosymmetric matrix.
*
* ## Notes
*
* - The implementation must rely on manually checking that \\(M_{ij} = M_{N-i-1,N-j-1}\\), and, while element access is deterministic, no way exists to prevent cache misses outside of reordering the underlying matrix elements, thus incurring a larger performance penalty than just "jumping around" in a single pass.
* - Worst case scenario: O(N^2).
*
* @param v - value to test
* @returns boolean indicating if a value is a centrosymmetric matrix
*
* @example
* var ndarray = require( '@stdlib/ndarray/ctor' );
*
* var arr = ndarray( 'generic', [ 2, 1, 1, 2 ], [ 2, 2 ], [ 2, 1 ], 0, 'row-major' );
*
* var bool = isCentrosymmetricMatrix( arr );
* // returns true
*
* bool = isCentrosymmetricMatrix( [] );
* // returns false
*/
declare function isCentrosymmetricMatrix( v: any ): v is ndarray;
// EXPORTS //
export = isCentrosymmetricMatrix;