The program package VEC （Visual computing in Electron Crystallography） has been revised such that （i） a program converting one-line symbols to two-line symbols of （3＋1）-dimensional superspace groups has been incorporated into VEC so that the latter can interpret both kinds of symbols; （ii） a bug in calculating structure factors of onedimensionally incommensurate modulated crystals has been fixed. The correction has been verified by successfully matching the experimental electron microscopy image of an incommensurate crystal with a series of simulated images. The precompiled revised version of VEC and relevant materials are available on the Web at http：//cryst.iphy.ac.cn.
