CODEWITHSUNDEEP
rdataframefilter
user12711004
user12711004

Reputation:

Filter dataset with %in% with pattern

I’m using filter to my dataset to select certain values from column:


%>%
filter(col1 %in% c(“value1”, “value2"))

How ever I don’t understand how to filter values in column with pattern without fully writing it. For example I also want all values which start with “value3” (“value33”, “value34”,....) along with “value1” and “value2”. Can I add grepl to that vector?

Upvotes: 0

Views: 464

Answers (3)

Ronak Shah
Ronak Shah

Reputation: 389047

Here are few options in base R :

Using grepl : 

subset(df, grepl('^value', b))

#  a        b
#1 1   value3
#3 3 value123
#4 4  value12

Similar option with grep which returns index of match. 

df[grep('^value', df$b),]

However, a faster option would be to use startsWith

subset(df, startsWith(b, "value"))

All of this would select rows where column b starts with "value".

data

df <- data.frame(a = 1:5, b = c('value3', 'abcd', 'value123', 'value12', 'def'), 
                 stringsAsFactors = FALSE)

Upvotes: 0

MrFlick
MrFlick

Reputation: 206253

If you want to use another tidyverse package to help, you can use str_starts from stringr to find strings that start with a certain value

dd %>% filter(stringr::str_starts(col1, "value"))

Upvotes: 2

Adam B.
Adam B.

Reputation: 1180

You can use regular expressions to do that:

df %>%
   filter(str_detect('^value[1-3]'))

Upvotes: 3

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