Error function calculation device and error function calculation method

摘要

An error function calculation device, which performs processing of calculating an error function F_M(T) having T (positive real number) as a variable and M (M is an integer of 0 or more) as an order, includes a coefficient table and a calculation section. The coefficient table stores a value of F_M+i(T₀)/F_M(T₀) (i is at least one integer among 1 to n, and n is a natural number) calculated for T₀, obtained by an n-th order polynomial approximation of the error function F_M(T), or a multiplied value which is obtained by multiplying the value of F_M+i(T₀)/F_M(T₀) by a constant. The calculation section reads the value of F_M+i(T₀)/F_M(T₀) or the multiplied value from the coefficient table, and performs at least a part of the processing of calculating a value of the error function F_M(T) by a fixed-point arithmetic using the value of F_M+i(T₀)/F_M(T₀) or the multiplied value.