filtering a rows based on more than one column string-CodePudding

heres a dataframe:

#      A      B    C   D
# 0  loud    one   0   0
# 1  quite    one  1   2
# 2  silent   two  2   4
# 3  loud    three 3   6
# 4  quite    two  4   8
# 5  silent   two  5   10

and afterwards I want the dataframe to look like this:

#      A      B    C   D
# 0  loud    one   0   0
# 1  quite    one  1   2
# 2  loud    three 3   6
# 3  quite    two  4   8

How do I write a condition using dplyr extract or select functions where we use OR?.

eg. (dataframe is called volume) volume %<% filter(grepl(A, loud or quite))

CodePudding user response：

With dplyr filter and str_detect:

library(tidyverse)

tribble(
  ~A, ~B, ~C, ~D,
  "loud", "one", 0, 0,
  "quite", "one", 1, 2,
  "silent", "two", 2, 4,
  "loud", "three", 3, 6,
  "quite", "two", 4, 8,
  "silent", "two", 5, 10
) |> 
  filter(str_detect(A, "loud|quite"))
#> # A tibble: 4 × 4
#>   A     B         C     D
#>   <chr> <chr> <dbl> <dbl>
#> 1 loud  one       0     0
#> 2 quite one       1     2
#> 3 loud  three     3     6
#> 4 quite two       4     8

^{Created on 2022-05-17 by the reprex package (v2.0.1)}

CodePudding user response：

data.table option:

library(data.table)
setDT(df)[A %in% c("loud", "quite")]

Output:

       A     B C D
1:  loud   one 0 0
2: quite   one 1 2
3:  loud three 3 6
4: quite   two 4 8

Thanks to @Carl for creating the data!