theta.php

Go to the documentation of this file.

<?php

namespace Complex;

if (!function_exists(__NAMESPACE__ . '\\theta')) {
    function theta($complex): float
    {
        $complex = Complex::validateComplexArgument($complex);

        if ($complex->getReal() == 0.0) {
            if ($complex->isReal()) {
                return 0.0;
            } elseif ($complex->getImaginary() < 0.0) {
                return M_PI / -2;
            }
            return M_PI / 2;
        } elseif ($complex->getReal() > 0.0) {
            return \atan($complex->getImaginary() / $complex->getReal());
        } elseif ($complex->getImaginary() < 0.0) {
            return -(M_PI - \atan(\abs($complex->getImaginary()) / \abs($complex->getReal())));
        }

        return M_PI - \atan($complex->getImaginary() / \abs($complex->getReal()));
    }
}