问题
I would like to filter a dataframe using filter() and str_detect() matching for multiple patterns without multiple str_detect() function calls. In the example below I would like to filter the dataframe df
to show only rows containing the letters a
f
and o
.
df <- data.frame(numbers = 1:52, letters = letters)
df %>%
filter(
str_detect(.$letters, "a")|
str_detect(.$letters, "f")|
str_detect(.$letters, "o")
)
# numbers letters
#1 1 a
#2 6 f
#3 15 o
#4 27 a
#5 32 f
#6 41 o
I have attempted the following
df %>%
filter(
str_detect(.$letters, c("a", "f", "o"))
)
# numbers letters
#1 1 a
#2 15 o
#3 32 f
and receive the following error
Warning message: In stri_detect_regex(string, pattern, opts_regex = opts(pattern)) : longer object length is not a multiple of shorter object length
回答1:
The correct syntax to accomplish this with filter() and str_detect() would be
df %>%
filter(
str_detect(letters, "a|f|o")
)
# numbers letters
#1 1 a
#2 6 f
#3 15 o
#4 27 a
#5 32 f
#6 41 o
来源:https://stackoverflow.com/questions/44759180/filter-by-multiple-patterns-with-filter-and-str-detect