Hi, Yes, this is correct. If you look in the HISTOGRAM documentation for the MAX keyword, it has the following note: Note: " style="margin: 6pt 0px; font-size: 9pt; color: #454545; font-family: Verdana, Arial, Helvetica, San-Serif;">Note: If NBINS is specified, the value for MAX will be adjusted to NBINS*BINSIZE + MIN. This ensures that the last bin has the same width as the other bins. So, in your first case, because you specified NBIN, then it adjusted your MAX value to be from 1.0 to 1.5, which includes your 1.3 value. In the second case, it didn't adjust the MAX value, so the 1.3 value is ignored. Hope this helps. Cheers, Chris