Patent ID: 8549056
Filing Date: 2013-10-01
Classification: G06F

Abstract:
1. An arctangent calculation apparatus comprising: a phase angle memory unit in which a phase angle is stored in advance, the phase angle corresponding to a two-dimensional vector value corresponding to in a range of 0° to substantially 22.5°; a vector rotation unit that performs a vector rotation operation on a two-dimensional vector value corresponding to in a range of 0° to 360° and converts the two-dimensional vector value corresponding to in a range of 0° to 360° into a two-dimensional vector value corresponding to in a range of 0° to substantially 22.5°; an arctangent calculation unit that outputs, from the phase angle memory unit, a phase angle that corresponds to the two-dimensional vector value corresponding to in a range of 0° to substantially 22.5° obtained by conversion by the vector rotation unit; and a phase angle conversion unit that converts the phase angle output by the arctangent calculation unit into a phase angle in a range of 0° to 360°.