This suggests that maybe the first line is a buglet (without any real consequence), since there happens to be no good reason to require that array to be single precision. I think it's reasonable to say that we should use double precision (float/float_/float64) everywhere floating point is needed, since a) that's what Python floats are and b) it's on the safe side precision-wise, and c) that's what most (if not all) of the C++ extensions, such as _backend_agg.cpp expect. Exceptions would be when some binary interface or file format etc. requires otherwise.
Note, the first line also has a moderate performance penalty since the array might be converted twice (once for asarray, and once for astype). It would be better to do: x = np.asarray(x, np.float_) As for the distinction between the last two, I think it is primarily a style issue. I don't have a strong feeling either way, but consistency would be an improvement, I suppose. Cheers, Mike Stéfan van der Walt wrote: > 2008/6/12 Manuel Metz <[EMAIL PROTECTED]>: > >> When looking, e.g. at axes.py, I see 3 different arguments passed to >> numpy astype()/array()/zero() and friends: >> >> x = np.asarray(x).astype(np.float32) >> x = np.zeros( x, np.float_ ) >> x = np.ones((col,), float) >> >> Is there a preferred one to stick to ?! >> > > Both `np.float_` and the Python `float` are interpreted as > `np.float64`. The only time you really need something other than > `float` is if you require a width other than 64 (like in the first > line you showed). > > Regards > Stéfan > > ------------------------------------------------------------------------- > Check out the new SourceForge.net Marketplace. > It's the best place to buy or sell services for > just about anything Open Source. > http://sourceforge.net/services/buy/index.php > _______________________________________________ > Matplotlib-devel mailing list > Matplotlib-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-devel > -- Michael Droettboom Science Software Branch Operations and Engineering Division Space Telescope Science Institute Operated by AURA for NASA ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://sourceforge.net/services/buy/index.php _______________________________________________ Matplotlib-devel mailing list Matplotlib-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
