[datatable-help] About adding fastmatch and fasttime to data.table

[Matthew Dowle]

Hi, 

This sounds like a geat idea. I don't know why Simon U didn't
reply, or without success, so that may depend on the way you asked,
whether he is on holiday at the moment, his reaction to the precise
wording of the email you wrote, or some other factor. It is difficult to
tell! But we don't need to wait for him or for for you: this is open
source. You have got much further than I have so if you'd like to add
this please go ahead and make progress. You're very welcome to join the
project and commit directly. Or if you can't for some reason please file
as a feature request so it doesn't get forgotten. 

Matthew 

On
25.02.2013 18:40, stat quant wrote: 

> Hello list, 
> 
> Looking at
fastmatch and fasttime, I realized that those package consists solely in
1 C file (each). 
> We spoke about the possibility to add those to
data.table, I tried to contact S.Urbanek without any success so I do not
have feedback from his side. 
> Using fastPOSIXct provide a huge gain
when one have to load files with datetime, on my laptop using
data.table:::fread, I realized that most of the time is spent casting
datetimes to POSIXct (I have several columns). 
> 
> Looking at
fasttime, you can see pretty good improvement (factor 15) 
> 
> R) ts R)
system.time(a utilisateur système écoulé 
> 6.49 0.04 6.57 
> R)
system.time(b utilisateur système écoulé 
> 0.40 0.00 0.41 
> 
> When
colClasses will be implemented in fread, can I suggest to allow using
fasttime as an option ? 
> Concerning fastmatch, the vignette already
shows some nice benchmarks, I tend to do a lot of selects based on
string columns, not sure if this is the case for most of us. 
> 
> My
0.002 cent 
> Cheers

 
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