[R] how to remove factors from whole dataframe?

[Luigi Marongiu]

Awesome, thanks!

On Sun, Sep 19, 2021 at 4:22 PM Rui Barradas <ruipbarradas using sapo.pt> wrote:
>
> Hello,
>
> Using Jim's lapply(., is.factor) but simplified, you could do
>
>
> df1 <- df
> i <- sapply(df1, is.factor)
> df1[i] <- lapply(df1[i], as.character)
>
>
> a one-liner modifying df, not df1 is
>
>
> df[sapply(df, is.factor)] <- lapply(df[sapply(df, is.factor)], as.character)
>
>
> Hope this helps,
>
> Rui Barradas
>
> Às 11:03 de 19/09/21, Luigi Marongiu escreveu:
> > Thank you Jim, but I obtain:
> > ```
> >> str(df)
> > 'data.frame': 5 obs. of  3 variables:
> >   $ region : Factor w/ 5 levels "A","B","C","D",..: 1 2 3 4 5
> >   $ sales  : num  13 16 22 27 34
> >   $ country: Factor w/ 5 levels "a","b","c","d",..: 1 2 3 4 5
> >> df1<-df[,!unlist(lapply(df,is.factor))]
> >> str(df1)
> >   num [1:5] 13 16 22 27 34
> >> df1
> > [1] 13 16 22 27 34
> > ```
> > I was expecting
> > ```
> > str(df)
> > 'data.frame': 5 obs. of  3 variables:
> >   $ region : char "A","B","C","D",..: 1 2 3 4 5
> >   $ sales  : num  13 16 22 27 34
> >   $ country: char "a","b","c","d",..: 1 2 3 4 5
> > ```
> >
> > On Sun, Sep 19, 2021 at 11:37 AM Jim Lemon <drjimlemon using gmail.com> wrote:
> >>
> >> Hi Luigi,
> >> It's easy:
> >>
> >> df1<-df[,!unlist(lapply(df,is.factor))]
> >>
> >> _except_ when there is only one column left, as in your example. In
> >> that case, you will have to coerce the resulting vector back into a
> >> one column data frame.
> >>
> >> Jim
> >>
> >> On Sun, Sep 19, 2021 at 6:18 PM Luigi Marongiu <marongiu.luigi using gmail.com> wrote:
> >>>
> >>> Hello,
> >>> I woul dlike to remove factors from all the columns of a dataframe.
> >>> I can do it n a column at the time with
> >>> ```
> >>>
> >>> df <- data.frame(region=factor(c('A', 'B', 'C', 'D', 'E')),
> >>>                   sales = c(13, 16, 22, 27, 34), country=factor(c('a',
> >>> 'b', 'c', 'd', 'e')))
> >>>
> >>> new_df$region <- droplevels(new_df$region)
> >>> ```
> >>>
> >>> What is the syntax to remove all factors at once (from all columns)?
> >>> For this does not work:
> >>> ```
> >>>> str(df)
> >>> 'data.frame': 5 obs. of  3 variables:
> >>>   $ region : Factor w/ 5 levels "A","B","C","D",..: 1 2 3 4 5
> >>>   $ sales  : num  13 16 22 27 34
> >>>   $ country: Factor w/ 5 levels "a","b","c","d",..: 1 2 3 4 5
> >>>> df = droplevels(df)
> >>>> str(df)
> >>> 'data.frame': 5 obs. of  3 variables:
> >>>   $ region : Factor w/ 5 levels "A","B","C","D",..: 1 2 3 4 5
> >>>   $ sales  : num  13 16 22 27 34
> >>>   $ country: Factor w/ 5 levels "a","b","c","d",..: 1 2 3 4 5
> >>> ```
> >>> Thank you
> >>>
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> >>> and provide commented, minimal, self-contained, reproducible code.
> >
> >
> >



-- 
Best regards,
Luigi