PHP 忒聊 綴豖 ヶ輛 atan2 (PHP 3 = 3.0.5, PHP 4) Description This function calculates the arc tangent of the two variables x and y. It is similar to calculating the arc tangent of y / x, except that the signs of both arguments are used to determine the quadrant of the result. The function returns the result in radians, which is between -PI and PI (inclusive). See also acos() and atan(). 綴豖 れ萸 ヶ輛 asinh 奻珨撰 atan