On Tue, Jan 3, 2012 at 12:46 PM, Wes McKinney <wesmck...@gmail.com> wrote: > On Tue, Jan 3, 2012 at 1:06 PM, Jim Vickroy <jim.vick...@noaa.gov> wrote: >> On 1/3/2012 10:46 AM, Ognen Duzlevski wrote: >>> Hello, >>> >>> I am playing with adding an enum dtype to numpy (to get my feet wet in >>> numpy really). I have looked at the >>> https://github.com/martinling/numpy_quaternion and I feel comfortable >>> with my understanding of adding a simple type to numpy in technical >>> terms. >>> >>> I am mostly a C programmer and have programmed in Python but not at >>> the level where my code wcould be considered "pretty" or maybe even >>> "pythonic". I know enums from C and have browsed around a few python >>> enum implementations online. Most of them use hash tables or lists to >>> associate names to numbers - these approaches just feel "heavy" to me. >>> >>> What would be a proper "numpy approach" to this? I am looking mostly >>> for direction and advice as I would like to do the work myself :-) >>> >>> Any input appreciated :-) >>> Ognen >> >> Does "enumerate" >> (http://docs.python.org/library/functions.html#enumerate) work for you? > That's not exactly what he means. The R lingo for this concept is > "factor" or a bit more common "categorical variable": > > http://stat.ethz.ch/R-manual/R-patched/library/base/html/factor.html > > FWIW R's factor type is implemented using hash tables. I do the same in > pandas. > > - Wes
Wes, You are right, "categorical variable" is what I am after. Thanks for the pointer, I will go the klib route you suggested and see what comes out. I may be "old fashioned" a bit in the sense that adding dependencies on external libraries is something I am reluctant to do - this is why I said using hashes may have felt a bit "heavy". But that may be my shortcoming :-) Ognen _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
