I agree, genloadtxt is a bit blotted, and it's not a surprise it's slower than the initial one. I think that in order to be fair, comparisons must be performed with matplotlib.mlab.csv2rec, that implements as well the autodetection of the dtype. I'm quite in favor of keeping a lite version around. On Dec 1, 2008, at 4:47 PM, Stéfan van der Walt wrote:
I haven't investigated the code in too much detail, but wouldn't it be possible to implement the current set of functionality in a base-class, which is then specialised to add the rest? That way, one could always instantiate TextReader yourself for some added speed.
Well, one of the issues is that we need to keep the function compatible w/ urllib.urlretrieve (Ryan, am I right?), which means not being able to go back to the beginning of a file (no call to .seek). Another issue comes from the possibility to define the dtype automatically: you need to keep track of the converters, then have to do a second loop on the data. Those converters are likely the bottleneck, as you need to check whether each value can be interpreted as missing or not and respond appropriately. I thought about creating a base class, with a specific subclass taking care of the missing values. I found out it would have duplicated a lot of code In any case, I think that's secondary: we can always optimize pieces of the code afterwards. I'd like more feedback on corner cases and usage...