[R] read.table
Gabor Grothendieck
ggrothendieck at gmail.com
Wed Jul 13 23:18:01 CEST 2005
Maybe you don't really need a data frame in the first place?
You were concerned with speed and matrices tend to
have higher performance than data frames.
On 7/13/05, Weiwei Shi <helprhelp at gmail.com> wrote:
> that sort of works for my purpose.
>
> btw, is there a bettter way to get data.frame by passing around
> matrix(). Since I could not find data.frame() with nrow or ncol
> arguments. so i have to use matrix first and then as.data.frame to
> convert it.
>
> is there any other (better) way?
>
> weiwei
>
> On 7/13/05, Gabor Grothendieck <ggrothendieck at gmail.com> wrote:
> >
> > You could use the nlines= argument to scan to read in a
> > portion at a time.
> >
> >
> >
> > On 7/13/05, Weiwei Shi <helprhelp at gmail.com> wrote:
> > >
> > > add:
> > > I used
> > > trn<-matrix(scan('train1.dat', sep='|', na.string='.'), nrow=273529,
> > ncol=195)
> > >
> > > it is done.
> > > so it seems that I just have no patience to wait for half an hour :)
> > >
> > > but i still have that question:
> > > is there a way to track the process if it takes too long. Could we
> > > stop in the middle to see at which line it "hesitates" to move on?
> > >
> > > regards,
> > >
> > > weiwei
> > >
> > >
> > > On 7/13/05, Weiwei Shi <helprhelp at gmail.com> wrote:
> > > > Hi,
> > > > I have a question on read.table.
> > > >
> > > > I have a dataset with 273,000 lines and 195 columns. I used the
> > > > read.table to load the data into R:
> > > > trn<-read.table('train1.dat', header=F, sep='|', na.strings='.')
> > > > I found it takes forever.
> > > >
> > > > then I run 1/10 of the data (test) using read.table again. And this
> > > > time it finished quickly. So, there might be something wrong in my
> > > > data format causing that problem.
> > > >
> > > > then, my question is, is there a way in R to track at which line,
> > > > something wrong occurs?
> > > >
> > > > Thanks,
> > > >
> > > > Weiwei
> > > >
> > > >
> > > > --
> > > > Weiwei Shi, Ph.D
> > > >
> > > > "Did you always know?"
> > > > "No, I did not. But I believed..."
> > > > ---Matrix III
> > > >
> > >
> > >
> > > --
> > > Weiwei Shi, Ph.D
> > >
> > > "Did you always know?"
> > > "No, I did not. But I believed..."
> > > ---Matrix III
> > >
> > > ______________________________________________
> > > R-help at stat.math.ethz.ch mailing list
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> > > PLEASE do read the posting guide!
> > http://www.R-project.org/posting-guide.html
> > >
> >
> >
>
>
> --
> Weiwei Shi, Ph.D
>
> "Did you always know?"
> "No, I did not. But I believed..."
> ---Matrix III
>
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