Simplified method of computing centroids of X-ray profiles

One definition employed by crystallographers in fixing the centroid of an X-ray diffraction profile has previously involved in its application the use of successive approximations. A simplified method, sufficiently accurate to eliminate such iterations in most cases, is given, based on the Thomsen & Yap analysis of statistical errors in centroid, median, and peak. Certain differences between the above error analysis and Wilson's recent work are discussed briefly.