| 摘要 |
PROBLEM TO BE SOLVED: To reduce errors and a memory area used for computing in calculation of a trigonometric function value. SOLUTION: This trigonometric function calculating device comprises an initial value decision step 10; a first term decision step 11; a core computing step 12; a computing frequency control step 13; a simple increment step; a set number control step 15; and a computing frequency initialization step 16. When computing operation following an addition theorem is divided into N pairs having different initial phase angles to be carried out by the core computing step for every phase increment value NΔserving as a reference, a computing frequency per a pair is lowered, and consequently, an accumulated error increasing along with the computing frequency can be reduced. In addition, a memory using quantity can be reduced since only the trigonometric function value of the phase increment value NΔserving as a reference and trigonometric function values of N initial phase angles are stored in the memory. COPYRIGHT: (C)2006,JPO&NCIPI
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