專利摘要：
The present invention discloses an apparatus and method for implementing an inverse arctangent function using piecewise linear theorem to simplify and used to transform a right-angled coordinate point X and Y to a phase angle θ of an inverse arctangent function. The present invention uses T-line combination to approach an inverse arctangent function between 0 degree to 45 degree, and determines which piecewise linear region the right-angled coordinate point is located at. A coefficient table stored in a memory is used to compute {circumflex over (θ)} which is the approximate value of the phase angle θ. The phase angle {circumflex over (θ)} between 45 degree to 360 degree can be mapped to the approximate phase angle {circumflex over (θ)} between 0 degree to 45 degree using linear combination.
The present invention discloses an apparatus and method for implementing an inverse arctangent function using piecewise linear theorem to simplify and used to transform a right-angled coordinate point X and Y to a phase angle theta of an inverse arctangent function. The present invention uses T-line combination to approach an inverse arctangent function between 0 degree to 45 degree, and determines which piecewise linear region the right-angled coordinate point is located at. A coefficient table stored in a memory is used to compute {circumflex over (theta)} which is the approximate value of the phase angle theta. The phase angle {circumflex over (theta)} between 45 degree to 360 degree can be mapped to the approximate phase angle {circumflex over (theta)} between 0 degree to 45 degree using linear combination.