I did an update to a Fedora 9 workstation yesterday that included updating numpy to 1.2.0 and matplotlib 0.98.3 (python version is 2.5.1). This seems to have played havoc with some of the histogram plotting we do. I was aware of the histogram changes in 1.2.0, but something doesn't seem to have worked out right. First issue is that the histogram function doesn't like giving "normed" any sort of a value. We get a "'NoneType' object is not iterable" error whenever we tried. I could work around this by editing function_base.py and given the normed keyword in the histogram function a default value of False, then changing the last few lines of histogram to read if not normed: return n, bins else : db = array(np.diff(bins), float) return n/(n*db).sum(), bins (i.e. using normed as a true boolean, rather than a testable variable). That seems to have fixed up that particular issue. I know this isn't quite the right place to report matplotlib errors, but the hist function expects the output of the histogram function, the left edges of the bins, and the frequency values, to be the same length. Histogram now returns all edges (e.g. 100), while the frequencies correspond to the number of bins (e.g. 99). Are these known issues? I didn't see anything in the numpy-1.2.1 release notes to indicate that this was addressed. I guess I should ask whether other people have even seen this? I can submit patches after I think a bit harder about proper fixes, but I'm not a programmer and anything I write should be considered highly suspect. Please advise. Thanks. Mike -- mike.ressler@alum.mit.edu