Data processing device, data processing method, and data processing program

A data processing method performed by a data processing device including:

• at least one processor that processes an n-th order polynomial with polynomial approximation for each piece with respect to an input,
• a look-up table configured to hold an approximation coefficient used for a polynomial approximation operation, and
• a total coefficient storage unit that stores approximation coefficients of all pieces when the polynomial approximation is performed, a number of approximation coefficients being larger than a number of table stages of the look-up table,
• the data processing method comprising, by the at least one processor:
• selecting an input value included in an input domain of the look-up table from among a plurality of input values that are values of inputs;
• selecting only an approximation coefficient of a piece necessary for the operation from the total coefficient storage unit;
• storing the selected approximation coefficient in the look-up table;
• outputting, from the look-up table, an approximation coefficient corresponding to the selected input value;
• and
• performing the polynomial approximation operation by using the selected input value and the output approximation coefficient.

A non-transitory recording medium storing a data processing program of a data processing device including:

• at least one processor that processes an n-th order polynomial with polynomial approximation for each piece with respect to an input,
• a look-up table configured to hold an approximation coefficient used for a polynomial approximation operation, and
• a total coefficient storage unit that stores approximation coefficients of all pieces when the polynomial approximation is performed, a number of approximation coefficients being larger than a number of table stages of the look-up table,
• the data processing program being executable by the at least one processor to perform processing comprising causing a computer to execute processing of, by the at least one processor:
• selecting an input value included in an input domain of the look-up table from among a plurality of input values that are values of inputs;
• selecting only an approximation coefficient of a piece necessary for the operation from the total coefficient storage unit;
• storing the selected approximation coefficient in the look-up table;
• outputting, from the look-up table, an approximation coefficient corresponding to the selected input value;
• and
• performing the polynomial approximation operation by using the selected input value and the output approximation coefficient.