[R] about data problem

Joe Ceradini joeceradini at gmail.com
Wed Sep 21 01:06:17 CEST 2016


read.csv("your_data.csv", stringsAsFactors=FALSE)
(I'm just reiterating Jianling said...)

Joe

On Tue, Sep 20, 2016 at 4:56 PM, lily li <chocold12 at gmail.com> wrote:

> Is there a function in read.csv that I can use to avoid converting numeric
> to factor? Thanks a lot.
>
>
>
> On Tue, Sep 20, 2016 at 4:42 PM, lily li <chocold12 at gmail.com> wrote:
>
> > Thanks. Then what should I do to solve the problem?
> >
> > On Tue, Sep 20, 2016 at 4:30 PM, Jeff Newmiller <
> jdnewmil at dcn.davis.ca.us>
> > wrote:
> >
> >> I suppose you can do what works for your data, but I wouldn't recommend
> >> na.rm=TRUE because it hides problems rather than clarifying them.
> >>
> >> If in fact your data includes true NA values (the letters NA or simply
> >> nothing between the commas are typical ways this information may be
> >> indicated), then read.csv will NOT change from integer to factor
> >> (particularly if you have specified which markers represent NA using the
> >> na.strings argument documented under read.table)... so you probably DO
> have
> >> unexpected garbage still in your data which could be obscuring valuable
> >> information that could affect your conclusions.
> >> --
> >> Sent from my phone. Please excuse my brevity.
> >>
> >> On September 20, 2016 3:11:42 PM PDT, lily li <chocold12 at gmail.com>
> >> wrote:
> >> >I reread the data, and use 'na.rm = T' when reading the data. This time
> >> >it
> >> >has no such problem. It seems that the existence of NAs convert the
> >> >integer
> >> >to factor. Thanks for your help.
> >> >
> >> >
> >> >On Tue, Sep 20, 2016 at 4:09 PM, Jianling Fan <fanjianling at gmail.com>
> >> >wrote:
> >> >
> >> >> Add the "stringsAsFactors = F"  when you read the data, and then
> >> >> convert them to numeric.
> >> >>
> >> >> On 20 September 2016 at 16:00, lily li <chocold12 at gmail.com> wrote:
> >> >> > Yes, it is stored as factor. I can't check out any problem in the
> >> >> original
> >> >> > data. Reread data doesn't help either. I use read.csv to read in
> >> >the
> >> >> data,
> >> >> > do you think it is better to use read.table? Thanks again.
> >> >> >
> >> >> > On Tue, Sep 20, 2016 at 3:55 PM, Greg Snow <538280 at gmail.com>
> >> >wrote:
> >> >> >
> >> >> >> This indicates that your Discharge column has been
> >> >stored/converted as
> >> >> >> a factor (run str(df) to verify and check other columns).  This
> >> >> >> usually happens when functions like read.table are left to try to
> >> >> >> figure out what each column is and it finds something in that
> >> >column
> >> >> >> that cannot be converted to a number (possibly an oh instead of a
> >> >> >> zero, an el instead of a one, or just a letter or punctuation mark
> >> >> >> accidentally in the file).  You can either find the error in your
> >> >> >> original data, fix it, and reread the data, or specify that the
> >> >column
> >> >> >> should be numeric using the colClasses argument to read.table or
> >> >other
> >> >> >> function.
> >> >> >>
> >> >> >>
> >> >> >>
> >> >> >> On Tue, Sep 20, 2016 at 3:46 PM, lily li <chocold12 at gmail.com>
> >> >wrote:
> >> >> >> > Hi R users,
> >> >> >> >
> >> >> >> > I have a problem in reading data.
> >> >> >> > For example, part of my dataframe is like this:
> >> >> >> >
> >> >> >> > df
> >> >> >> > month day year          Discharge
> >> >> >> >    3        1   2010                6.4
> >> >> >> >    3        2   2010               7.58
> >> >> >> >    3        3   2010               6.82
> >> >> >> >    3        4   2010               8.63
> >> >> >> >    3        5   2010               8.16
> >> >> >> >    3        6   2010               7.58
> >> >> >> >
> >> >> >> > Then if I type summary(df), why it converts the discharge data
> >> >to
> >> >> >> levels? I
> >> >> >> > also met the same problem when reading some other csv files. How
> >> >to
> >> >> solve
> >> >> >> > this problem? Thanks.
> >> >> >> >
> >> >> >> > Discharge
> >> >> >> > 7.58     :2
> >> >> >> > 6.4       :1
> >> >> >> > 6.82     :1
> >> >> >> > 8.63     :1
> >> >> >> > 8.16     :1
> >> >> >> >
> >> >> >> >         [[alternative HTML version deleted]]
> >> >> >> >
> >> >> >> > ______________________________________________
> >> >> >> > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more,
> >> >see
> >> >> >> > https://stat.ethz.ch/mailman/listinfo/r-help
> >> >> >> > PLEASE do read the posting guide http://www.R-project.org/
> >> >> >> posting-guide.html
> >> >> >> > and provide commented, minimal, self-contained, reproducible
> >> >code.
> >> >> >>
> >> >> >>
> >> >> >>
> >> >> >> --
> >> >> >> Gregory (Greg) L. Snow Ph.D.
> >> >> >> 538280 at gmail.com
> >> >> >>
> >> >> >
> >> >> >         [[alternative HTML version deleted]]
> >> >> >
> >> >> > ______________________________________________
> >> >> > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >> >> > https://stat.ethz.ch/mailman/listinfo/r-help
> >> >> > PLEASE do read the posting guide http://www.R-project.org/
> >> >> posting-guide.html
> >> >> > and provide commented, minimal, self-contained, reproducible code.
> >> >>
> >> >>
> >> >>
> >> >> --
> >> >> Jianling Fan
> >> >> 樊建凌
> >> >>
> >> >
> >> >       [[alternative HTML version deleted]]
> >> >
> >> >______________________________________________
> >> >R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >> >https://stat.ethz.ch/mailman/listinfo/r-help
> >> >PLEASE do read the posting guide
> >> >http://www.R-project.org/posting-guide.html
> >> >and provide commented, minimal, self-contained, reproducible code.
> >>
> >>
> >
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/
> posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.




-- 
Cooperative Fish and Wildlife Research Unit
Zoology and Physiology Dept.
University of Wyoming
JoeCeradini at gmail.com / 914.707.8506
wyocoopunit.org

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