# isSkewPersymmetricMatrix > Test if a value is a [skew-persymmetric matrix][persymmetric-matrix].
## Usage ```javascript var isSkewPersymmetricMatrix = require( '@stdlib/assert/is-skew-persymmetric-matrix' ); ``` #### isSkewPersymmetricMatrix( value ) Tests if a value is a [skew-persymmetric matrix][persymmetric-matrix]. ```javascript var ndarray = require( '@stdlib/ndarray/ctor' ); var arr = ndarray( 'generic', [ 2, 0, 0, -2 ], [ 2, 2 ], [ 2, 1 ], 0, 'row-major' ); var bool = isSkewPersymmetricMatrix( arr ); // returns true ```
## Examples ```javascript var ndarray = require( '@stdlib/ndarray/ctor' ); var isSkewPersymmetricMatrix = require( '@stdlib/assert/is-skew-persymmetric-matrix' ); var arr = ndarray( 'generic', [ 1, 0, 0, -1 ], [ 2, 2 ], [ 2, 1 ], 0, 'row-major' ); var out = isSkewPersymmetricMatrix( arr ); // returns true out = isSkewPersymmetricMatrix( [ 1, 2, 3, 4 ] ); // returns false out = isSkewPersymmetricMatrix( {} ); // returns false out = isSkewPersymmetricMatrix( null ); // returns false ```