R help - Jul 2019 - Matrix - remove [,1] from top row

Hello,

I am simply trying to remove the [,1] row from a matrix.  I tried to
search Google to see if I could find how that is removed, but could
not find a way to do it.

So I have the following:

                [,1]
date          2019-7-01
Peeps       5
days         7
worn          9

this is what I want:

date          2019-7-01
Peeps       5
days         7
worn          9

Any ideas?

Nic

Hello,

That is not a row, what you seem to have is an object of class  
"matrix" and when it's printed it prints the column names or [,1]
[,2] etc if there aren't any colnames. So your matrix has just one  
column and 4 rows with rownames 'date', 'Peeps', 'days',
'worn'.


Hope this helps,

Rui Barradas




Citando Nicola Cecchino <ncecchino at gmail.com>:
> Hello,
>
> I am simply trying to remove the [,1] row from a matrix.  I tried to
> search Google to see if I could find how that is removed, but could
> not find a way to do it.
>
> So I have the following:
>
>                 [,1]
> date          2019-7-01
> Peeps       5
> days         7
> worn          9
>
> this is what I want:
>
> date          2019-7-01
> Peeps       5
> days         7
> worn          9
>
> Any ideas?
>
> Nic
>
> ______________________________________________
> 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.

give your a matrix an empty column name.
> tmp <- matrix(1:4, 4, 1, dimnames=list(letters[1:4], NULL))
> tmp
  [,1]
a    1
b    2
c    3
d    4
> dimnames(tmp)[[1]]
[1] "a" "b" "c"
"d"
> dimnames(tmp)[[2]]
NULL
> dimnames(tmp)[[2]] <- ""
> tmp
a 1
b 2
c 3
d 4

On Tue, Jul 2, 2019 at 5:09 PM <ruipbarradas at sapo.pt>
wrote:
>
> Hello,
>
> That is not a row, what you seem to have is an object of class
> "matrix" and when it's printed it prints the column names or
[,1]
> [,2] etc if there aren't any colnames. So your matrix has just one
> column and 4 rows with rownames 'date', 'Peeps',
'days', 'worn'.
>
>
> Hope this helps,
>
> Rui Barradas
>
>
>
>
> Citando Nicola Cecchino <ncecchino at gmail.com>:
>
> > Hello,
> >
> > I am simply trying to remove the [,1] row from a matrix.  I tried to
> > search Google to see if I could find how that is removed, but could
> > not find a way to do it.
> >
> > So I have the following:
> >
> >                 [,1]
> > date          2019-7-01
> > Peeps       5
> > days         7
> > worn          9
> >
> > this is what I want:
> >
> > date          2019-7-01
> > Peeps       5
> > days         7
> > worn          9
> >
> > Any ideas?
> >
> > Nic
> >
> > ______________________________________________
> > 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.
>
> ______________________________________________
> 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.

(1) m[,1] is the first column of matrix (or dataframe) m.
(2) The first row of matrix or dataframe m is m[1,]
(3) To remove the first row of matrix or dataframe m,
    do m <- m[-1,]


On Wed, 3 Jul 2019 at 08:59, Nicola Cecchino <ncecchino at gmail.com>
wrote:
> Hello,
>
> I am simply trying to remove the [,1] row from a matrix.  I tried to
> search Google to see if I could find how that is removed, but could
> not find a way to do it.
>
> So I have the following:
>
>                 [,1]
> date          2019-7-01
> Peeps       5
> days         7
> worn          9
>
> this is what I want:
>
> date          2019-7-01
> Peeps       5
> days         7
> worn          9
>
> Any ideas?
>
> Nic
>
> ______________________________________________
> 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.
>
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