filter function in dplyr errors: object 'name' not found

Question

I have a data frame in R like so called UK_profiles:

row.names   id     name
1   1   8131437     Profile
2   2   8131719     WolverineCompetition
3   4   8132011     www.vaseline.com
4   10  23265829    www.keepingskinamazing.co.uk
5   23  8042743     Mobile
6   24  8043312     Test
7   25  90914664    Join Our Core
8   26  45272695    UDF
9   27  50547829    apps.euro-bureau.eu/fairathon
10  28  50916438    www.benjerry.intashop.com/
11  44  83667343    All Web Site Data
12  45  84556272    UK

Using dplyr I wish to filter and delete rows with grepl using:

require(dplyr) 

UK_profiles.filtered <- filter(UK_profiles, !grepl("Rollup|Microsite|Mobile|Test|tset|Profile|Facebook|Unfiltered|returnurl", name))

However, I get an error saying:

object 'name' not found.

I also get:

In data.matrix(data) : NAs introduced by coercion.

The object 'name' is clearly in the dataframe. Can someone please help?

Answer 1

It does seem like you are getting the stats::filter function and not the dplyr one. To make sure you get the right one, use the notation dplyr::filter.

d = data.frame(x=1:10,
 name=c("foo","bar","baz","bar","bar","baz","fnord","qar","qux","quux"))

filter(d, !grepl("ar|ux", name))
Error in grepl("ar|ux", name) : object 'name' not found

dplyr::filter(d, !grepl("ar|ux", name))
  x  name
1 1   foo
2 3   baz
3 6   baz
4 7 fnord

You don't even need to do library(dplyr) for this to work - you do need dplyr installed though.

This works for functions from any package.

Answer 2

To understand why this happens you can recreate the error quite straightforwardly by following these steps.

Load dplyr

Load dplyr into a new session with only default libraries loaded, filter will work as dplyr loaded after stats

library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#> 
#>     filter, lag
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union

filter(mtcars, mpg < 15)
#>    mpg cyl disp  hp drat    wt  qsec vs am gear carb
#> 1 14.3   8  360 245 3.21 3.570 15.84  0  0    3    4
#> 2 10.4   8  472 205 2.93 5.250 17.98  0  0    3    4
#> 3 10.4   8  460 215 3.00 5.424 17.82  0  0    3    4
#> 4 14.7   8  440 230 3.23 5.345 17.42  0  0    3    4
#> 5 13.3   8  350 245 3.73 3.840 15.41  0  0    3    4

Unload dplyr

This causes the error as now trying to use stats::filter. By unloading stats we see another error that there is no function called filter found at all

detach("package:dplyr")  # Unload dplyr
filter(mtcars, mpg < 15)  # Using stats::filter
#> Error in filter(., mpg < 15): object 'mpg' not found

detach("package:stats")  # Unload stats

filter(mtcars, mpg < 15)    
#> Error in filter(., mpg < 15): could not find function "filter"

Reload stats and dplyr

Make sure to reload dplyr after stats and we see that the dplyr version of filter works again

library(stats)
library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> 
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union

filter(mtcars, mpg < 15)
#>    mpg cyl disp  hp drat    wt  qsec vs am gear carb
#> 1 14.3   8  360 245 3.21 3.570 15.84  0  0    3    4
#> 2 10.4   8  472 205 2.93 5.250 17.98  0  0    3    4
#> 3 10.4   8  460 215 3.00 5.424 17.82  0  0    3    4
#> 4 14.7   8  440 230 3.23 5.345 17.42  0  0    3    4
#> 5 13.3   8  350 245 3.73 3.840 15.41  0  0    3    4