I'm trying to find the indices in an array that have the lowest values, so that I can plot the corresponding values in another array. numpy.argsort would seem to be the proper approach here, but when I try it I get this error: Traceback (most recent call last): File "../scripts/findWorstFitPixel.py", line 48, in <module> indices = np.argsort(result) File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/numpy/core/fromnumeric.py", line 680, in argsort return argsort(axis, kind, order) TypeError: an integer is required The weird thing is that when I try to replicate the circumstances in the REPL (same argument shape/dtype passed to argsort), it succeeds. So there must be something subtle going on here. My input is a length-270336 1D array of float32s, each of which was generated by scipy.stats.pearsonr and almost all of which have values between .95 and 1. Any ideas what I can investigate to get this working? Unfortunately my script relies on reading a bunch of files, so I can't very well upload a working sample, but the script itself is here: http://pastebin.com/Rxcbyb8p Thanks for any assistance! -Chris