Data generation method and data generation apparatus

Abstract

A candidate extraction unit () executes candidate extraction processing wherein a fixed number of consecutive height data items are extracted from one line of height data using a certain sample point as the starting point, the median for the extracted height data items and the difference therefrom for each extracted height data item are calculated, and sample points with a difference that is at least a height threshold are extracted as singular point candidates. An interpolation unit () determines, to be a singular point, a singular point candidate having a number of consecutive repetitions that is less than a width threshold, deletes the height data for the determined singular point, interpolates the deleted height data using height data for sample points which are adjacent to and other than such singular point, and generates shape data for evaluating runout and bulge/dent.