[R] How to remove all rows that have a numeric in the first (or any) column

[Avi Gross]

Calling something a data.frame does not make it a data.frame.

The abbreviated object shown below is a list of singletons. If it is a column in a larger object that is a data.frame, then it is a list column which is valid but can be ticklish to handle within base R but less so in the tidyverse.

For example, if I try to make a data.frame the normal way, the list gets made into multiple columns and copied to each row. Not what was expected. I think some tidyverse functionality does better.

Like this:

library(tidyverse)
temp=list("Hello", 1, 1.1, "bye")

Now making a data.frame has an odd result:

> mydf=data.frame(alpha=1:4, beta=temp)
> mydf
alpha beta..Hello. beta.1 beta.1.1 beta..bye.
1     1        Hello      1      1.1        bye
2     2        Hello      1      1.1        bye
3     3        Hello      1      1.1        bye
4     4        Hello      1      1.1        bye

But a tibble handles it:

> mydf=tibble(alpha=1:4, beta=temp)
> mydf
# A tibble: 4 x 2
alpha beta     
<int> <list>   
  1     1 <chr [1]>
  2     2 <dbl [1]>
  3     3 <dbl [1]>
  4     4 <chr [1]>

So if the data does look like this, with a list column, but access can be tricky as subsetting a list with [] returns a list and you need [[]].

I found a somehwhat odd solution like this:

mydf %>%
   filter(!map_lgl(beta, is.numeric)) -> mydf2
# A tibble: 2 x 2
alpha beta     
<int> <list>   
  1     1 <chr [1]>
  2     4 <chr [1]>

When I saved that result into mydf2, I got this.

Original:
  
  > str(mydf)
tibble [4 x 2] (S3: tbl_df/tbl/data.frame)
$ alpha: int [1:4] 1 2 3 4
$ beta :List of 4
..$ : chr "Hello"
..$ : num 1
..$ : num 1.1
..$ : chr "bye"

Output when any row with a numeric is removed:

> str(mydf2)
tibble [2 x 2] (S3: tbl_df/tbl/data.frame)
$ alpha: int [1:2] 1 4
$ beta :List of 2
..$ : chr "Hello"
..$ : chr "bye"

So if you try variations on your code motivated by what I show, good luck. I am sure there are many better ways but I repeat, it can be tricky.

-----Original Message-----
From: R-help <r-help-bounces using r-project.org> On Behalf Of Jeff Newmiller
Sent: Tuesday, September 14, 2021 11:54 PM
To: Gregg Powell <g.a.powell using protonmail.com>
Cc: Gregg Powell via R-help <r-help using r-project.org>
Subject: Re: [R] How to remove all rows that have a numeric in the first (or any) column

You cannot apply vectorized operators to list columns... you have to use a map function like sapply or purrr::map_lgl to obtain a logical vector by running the function once for each list element:

sapply( VPN_Sheet1$HVA, is.numeric )

On September 14, 2021 8:38:35 PM PDT, Gregg Powell <g.a.powell using protonmail.com> wrote:
>Here is the output:
>
>> str(VPN_Sheet1$HVA)
>List of 2174
> $ : chr "Email: fffd using fffffffffff.com"
> $ : num 1
> $ : chr "Eloisa Libas"
> $ : chr "Percival Esquejo"
> $ : chr "Louchelle Singh"
> $ : num 2
> $ : chr "Charisse Anne Tabarno, RN"
> $ : chr "Sol Amor Mucoy"
> $ : chr "Josan Moira Paler"
> $ : num 3
> $ : chr "Anna Katrina V. Alberto"
> $ : chr "Nenita Velarde"
> $ : chr "Eunice Arrances"
> $ : num 4
> $ : chr "Catherine Henson"
> $ : chr "Maria Carla Daya"
> $ : chr "Renee Ireine Alit"
> $ : num 5
> $ : chr "Marol Joseph Domingo - PS"
> $ : chr "Kissy Andrea Arriesgado"
> $ : chr "Pia B Baluyut, RN"
> $ : num 6
> $ : chr "Gladys Joy Tan"
> $ : chr "Frances Zarzua"
> $ : chr "Fairy Jane Nery"
> $ : num 7
> $ : chr "Gladys Tijam, RMT"
> $ : chr "Sarah Jane Aramburo"
> $ : chr "Eve Mendoza"
> $ : num 8
> $ : chr "Gloria Padolino"
> $ : chr "Joyce Pearl Javier"
> $ : chr "Ayza Padilla"
> $ : num 9
> $ : chr "Walfredson Calderon"
> $ : chr "Stephanie Anne Militante"
> $ : chr "Rennua Oquilan"
> $ : num 10
> $ : chr "Neil John Nery"
> $ : chr "Maria Reyna Reyes"
> $ : chr "Rowella Villegas"
> $ : num 11
> $ : chr "Katelyn Mendiola"
> $ : chr "Maria Riza Mariano"
> $ : chr "Marie Vallianne Carantes"
> $ : num 12
>
>‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
>
>On Tuesday, September 14th, 2021 at 8:32 PM, Jeff Newmiller <jdnewmil using dcn.davis.ca.us> wrote:
>
>> An atomic column of data by design has exactly one mode, so if any 
>> values are non-numeric then the entire column will be non-numeric. 
>> What does
>> 
>
>> str(VPN_Sheet1$HVA)
>> 
>
>> tell you? It is likely either a factor or character data.
>> 
>
>> On September 14, 2021 7:01:53 PM PDT, Gregg Powell via R-help r-help using r-project.org wrote:
>> 
>
>> > > Stuck on this problem - How does one remove all rows in a dataframe that have a numeric in the first (or any) column?
>> > 
>
>> > > Seems straight forward - but I'm having trouble.
>> > 
>
>> > I've attempted to used:
>> > 
>
>> > VPN_Sheet1 <- VPN_Sheet1[!is.numeric(VPN_Sheet1$HVA),]
>> > 
>
>> > and
>> > 
>
>> > VPN_Sheet1 <- VPN_Sheet1[!is.integer(VPN_Sheet1$HVA),]
>> > 
>
>> > Neither work - Neither throw an error.
>> > 
>
>> > class(VPN_Sheet1$HVA) returns:
>> > 
>
>> > [1] "list"
>> > 
>
>> > So, the HVA column returns a list.
>> > 
>
>> > > Data looks like the attached screen grab -
>> > 
>
>> > > The ONLY rows I need to delete are the rows where there is a numeric in the HVA column.
>> > 
>
>> > > There are some 5000+ rows in the actual data.
>> > 
>
>> > > Would be grateful for a solution to this problem.
>> > 
>
>> > How to get R to detect whether the value in column 1 is a number so the rows with the number values can be deleted?
>> > 
>
>> > > Thanks in advance to any and all willing to help on this problem.
>> > 
>
>> > > Gregg Powell
>> > 
>
>> > > Sierra Vista, AZ
>> 
>
>> --
>> 
>
>> Sent from my phone. Please excuse my brevity.
--
Sent from my phone. Please excuse my brevity.

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