/**
* Axiom: A⋅A⊥ = -A⊥⋅A
* Swapping operands changes the sign of the perp dot product
* @dataProvider dataProviderForPerpendicularIdentity
*/
public function testPerpDotProdcutSwapOperandsChangeSign(array $A)
{
$A = new Vector($A);
$A⊥ = $A->perpendicular();
$A⋅A⊥ = $A->dotProduct($A⊥);
$A⊥⋅A = $A⊥->dotProduct($A);
$this->assertEquals($A⋅A⊥, -$A⊥⋅A);
}
public function testPerpendicularExceptionNGreaterThanTwo()
{
$A = new Vector([1, 2, 3]);
$this->setExpectedException('MathPHP\\Exception\\VectorException');
$A->perpendicular();
}