[R] "invalid argument to unary operator" while selecting rows by name

Pauline Laïlle pauline.laille at gmail.com
Wed Sep 21 09:49:51 CEST 2016


Hi, thanks for the answer.
In this case, the row named "601" is not the 601st row of the table, but
the 117th. data[601,] actually refers to a non existing row.
I was wondering why data[-"601,] generates an error message whereas
data["601",] does not?

2016-09-20 19:08 GMT+02:00 Bert Gunter <bgunter.4567 at gmail.com>:

> Hint: "601"  is not 601.
>
> Have you gone through any R tutorials?
>
> Cheers,
> Bert
> Bert Gunter
>
> "The trouble with having an open mind is that people keep coming along
> and sticking things into it."
> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
>
>
> On Tue, Sep 20, 2016 at 5:42 AM, Pauline Laïlle
> <pauline.laille at gmail.com> wrote:
> > Dear all,
> >
> > I built a dataframe with read.csv2(). Initially, row names are integers
> > (order of answers to a survey). They are listed in the csv's first
> column.
> > The import works well and my dataframe looks like I wanted it to look.
> >
> > Row names go as follows :
> >  [1] "6"   "29"  "31"  "32"  "52"  "55"  "63"  "71"  "72"  "80"  "88"
> "89"
> >  "91"  "93"  "105" "110" "111" "117" "119" "120"
> >  [21] "122" "127" "128" "133" "137" "140" "163" "165" "167" "169" "177"
> > "178" "179" "184" "186" "192" "193" "200" "201" "228"
> > etc.
> >
> > I would like to drop rows "601" & "604" to clean the dataframe.
> >
> > While data["601",] shows me the first row i'd like to drop, data[-"601",]
> > returns the following :
> > Error in -"601" : invalid argument to unary operator
> >
> > idem with data[c("601","604"),] and data[-c("601","604"),]
> >
> > It is the first time that I run into this specific error. After reading a
> > bit about it I still don't understand what it means and how to fix it.
> >
> > Thanks for reading!
> > Best,
> > Pauline.
> >
> >         [[alternative HTML version deleted]]
> >
> > ______________________________________________
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>

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