Trigonometric function approximation apparatus, trigonometric function approximation method, and trigonometric function approximation program

摘要

The main generator (11) generates a first sawtooth signal (501) that is tuned to the ideal function using the phase signal (51). The adjustment unit (121) generates an adjustment signal (604) obtained by multiplying the phase signal (51) by a constant and adding the constant. The sub-generation unit (122) uses the adjustment signal (604) to cancel an error function in which the phase and frequency represent an error from the approximate triangular wave signal generated from the first sawtooth wave signal (501). A second triangular wave signal (602) that is the same as the correction signal (603) is generated. The second correction unit (123) adjusts the value range of the waveform of the second triangular wave signal (602) to generate an error correction signal (603). An adder (113) adds the first sawtooth signal (501) and the error correction signal (603) to generate a corrected sawtooth signal (501a). An approximate signal generation unit (114) generates an approximate signal (52) using the corrected sawtooth signal (501a).