Filtering rows based on partial matching between a data frame and a vector

Question

I have a data frame and want to filter it based on the partial match of names in the first column with the names in the vector.

nam <- c('mmu_mir-1-3p','mmu_mir-1-5p','mmu-mir-3-5p','mir-4','mmu-mir-6-3p') #factor
aa <- c('12854','36','5489','54485','2563') #numeric
df <- data.frame(nam,aa)

vector <- c('mir-1','mir-3','mir-6')

I need to have rows in the new data frame where names in df$nam are partially matching with the names in vector. So new_df should look like this.

new_nam <- c('mmu_mir-1-3p','mmu_mir-1-5p','mmu-mir-3-5p','mmu-mir-6-3p')  #factor
new_aa <- c('12854','36','5489','2563')  #numeric
new_df <- data.frame(new_nam,new_aa)

Not directly about the question, but why do you have numeric columns as strings? — camille
Does this answer your question? How to use dplyr::filter() to return only rows where the value contains one or more of a given vector of strings? — camille
A few more examples (not exact duplicates, but similar ideas) here — camille
The numeric column is not a value for the first column, they are supposed to be a string — Apex
Since the structure of the names are different, for some reasons I was losing several rows in my new df — Apex

akrun akrun · Accepted Answer · 2020-02-13T16:13:05

We can paste the elements of 'vector' into a single string collapsed by | and usse that in grepl or str_detect to filter the rows

library(dplyr)
library(stringr)
df %>% 
   filter(str_detect(nam, str_c(vector, collapse="|")))
#           nam    aa
#1 mmu_mir-1-3p 12854
#2 mmu_mir-1-5p    36
#3 mmu-mir-3-5p  5489
#4 mmu-mir-6-3p  2563

In base R, this can be done with subset/grepl

subset(df, grepl(paste(vector, collapse= "|"), nam))

Filtering rows based on partial matching between a data frame and a vector

1 Answers