METHOD AND DEVICE FOR DIGITAL DATA INTERPOLATION

PURPOSE:To improve the calculation precision by dividing the product between a digital data string and a coefficient into three parts and applying direct addition in the case of a set of specific data and applying the Euler conversion method to obtain the sum otherwise. CONSTITUTION:A limited number of successively coming input digital data are stored in a data memory 2, and a preliminarily calculated numerical value is stored as coefficient data in a coefficient memory 3. A control circuit 1 preliminarily divides a small number of sets of specific data and the other sets from each other and successively reads out input digital data AK from the data memory 2 and successively reads out coefficient data CK from the coefficient memory 3 and inputs these data AK and CK to a product calculating circuit 5 as one set. This product calculating circuit 5 calculates a product D, between input data AK and coefficient data CK, and the product is directly sent to an adder 8 in the case of sets of specific data commanded by the control circuit 1 but is sent to an Euler total sum circuit 7 through a difference calculating circuit 6 in the case of the other sets of data.