assertEquals(1.825, StandardDeviation::population($population), '', $delta); //http://www.stat.wmich.edu/s216/book/node126.html $delta = 0.5; $population = [7100, 15500, 4400, 4400, 5900, 4600, 8800, 2000, 2750, 2550, 960, 1025]; $this->assertEquals(4079, StandardDeviation::population($population), '', $delta); $population = [9300, 10565, 15000, 15000, 17764, 57000, 65940, 73676, 77006, 93739, 146088, 153260]; $this->assertEquals(50989, StandardDeviation::population($population), '', $delta); } /** * @expectedException \Phpml\Exception\InvalidArgumentException */ public function testThrowExceptionOnEmptyArrayIfNotSample() { StandardDeviation::population([], false); } /** * @expectedException \Phpml\Exception\InvalidArgumentException */ public function testThrowExceptionOnToSmallArray() { StandardDeviation::population([1]); } }