Grace Fang wrote: > Hi, > > I am writing code to sort the columns according to the sum of each > column. The dataset is huge (50k rows x 300k cols), so i need to read > line by line and do the summation to avoid the out-of-memory problem. > But I don't know why it runs very slow, and part of the code is as > follows. I suspect it's because of array index, but not sure. Can > anyone > point out what needs to be modified to make it run fast? thanks in > advance!
Array indexing is unlikely to be the culprit. Could it not just be slow, because you are processing a lot of data? With numbers those big I would expect to have enough time to go make a coffee, then drink it. If you think it is slower than it could be, post more code for optimization advice... Will McGugan -- http://www.willmcgugan.com -- http://mail.python.org/mailman/listinfo/python-list
