In structural analysis it is sometimes necessary to rotate the fabric data on projection diagrams. A program for the rotation has been developed for a personal computer (NEC 9801). The program is designed to rotate each projected point, which represents orientation of a fabric element, through a given angular distance in a given sense on projection diagram.

Using the program now prepared, combined with another one written by HAYASHI et al. (1987), it is possible to draw orientation diagrams to evaluate preferred orientation of microscopic fabric elements as well as mesoscopic to macroscopic ones.