Stefan van der Walt wrote: > Hi all, > > Some of you may have seen the interesting thread on Fortran-ordering > earlier. I thought it might be fun to set up a short quiz which tests > your knowledge on the topic. > > If you're up for the challenge, take a look at > > http://mentat.za.net/numpy/quiz > > I won't be held liable for any emotional trauma caused, self-inflicted > wounds or brain-core meltdowns. >
Cute (especially the comment if you get them all right). I'm not sure if this quiz is a veiled complaint about the rules for Fortran ordering or not ;-) In my mind the Fortran ordering rules are consistent (if not completely bug-free). You just have to get the right idea of what is meant by the order argument when you use it. If you think you are having trouble figuring out the rules, think of the trouble it was to figure out what they should be and then to code them up. Two rules help you pass the quiz with a perfect score: 1) On array construction, the order argument allows you to specify how the array will be organized in memory. This has no effect on what is printed as the user doesn't usually care how the array is stored in memory. So, you can ignore all order= expressions in the array construct for the quiz 2) On reshaping, the order argument specifies how you think the array is organized. Whenever you make a significant reshape you are telling the computer to re-interpret the chunk of data in a different way, it makes a big difference as to how you think about that chunk of data. Do you think of it as organized rows-first (C-order) or columns-first (Fortran-order). The order argument allows you to specify how you think about it and indicates the 1-d indexing order of the array. It also fills in the newly-shaped array in exactly that same order. Semantically, one could technically separate those two concepts and have one order argument that specifies how you think about the input and another that specifies how you think about the output. But, I really didn't want to go there and couldn't see a real advantage to that. So, the single order argument specifies how you think about both. -Travis ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Numpy-discussion mailing list Numpy-discussion@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/numpy-discussion
