Get nearest n matching strings

Question

Hi I am trying to match one string from other string in different dataframe and get nearest n matches based on score.

EX: from string_2 (df_2) column i need to match with string_1(df_1) and get the nearest 3 matches based on each ID group.

ID = c(100, 100,100,100,103,103,103,103,104,104,104,104)
string_1 = c("Jack Daniel","Jac","JackDan","steve","Mark","Dukes","Allan","Duke","Puma Nike","Puma","Nike","Addidas")

df_1 = data.frame(ID,string_1)

ID = c(100, 100, 185, 103,103, 104, 104,104)
string_2 = c("Jack Daniel","Mark","Order","Steve","Mark 2","Nike","Addidas","Reebok")

df_2 = data.frame(ID,string_2)

My output dataframe df_out will look like below.

ID = c(100, 100,185,103,103,104,104,104)
string_2 = c("Jack Daniel","Mark","Order","Steve","Mark 2","Nike","Addidas","Reebok")
nearest_str_match_1 = c("Jack Daniel","JackDan","NA","Duke","Mark","Nike","Addidas","Nike")
nearest_str_match_2 =c("JackDan","Jack Daniel","NA","Dukes","Duke","Addidas","Nike","Puma Nike") 
nearest_str_match_3 =c("Jac","Jac","NA","Allan","Allan","Puma","Puma","Addidas") 
   
df_out = data.frame(ID,string_2,nearest_str_match_1,nearest_str_match_2,nearest_str_match_3)

i have tried manually with package "stringdist" - 'jw' method and get the nearest value.

stringdist::stringdist("Jack Daniel","Jack Daniel","jw") 
stringdist::stringdist("Jack Daniel","Jac","jw")
stringdist::stringdist("Jack Daniel","JackDan","jw")

Thanks in advance

Onyambu · Accepted Answer · 2022-01-06T09:37:43.143

 merge(df_1, df_2, by = 'ID') %>%
   group_by(string_2) %>%
   mutate(dist = (stringdist::stringdist(string_2,string_1, 'jw')) %>%
            rank(ties = 'last')) %>%
   slice_min(dist, n = 3) %>%
   pivot_wider(names_from = dist, names_prefix = 'nearest_str_match_', 
               values_from = string_1)

# A tibble: 7 x 5
# Groups:   string_2 [7]
     ID string_2    nearest_str_match_1 nearest_str_match_2 nearest_str_match_3
  <dbl> <chr>       <chr>               <chr>               <chr>              
1   104 Addidas     Addidas             Nike                Puma               
2   100 Jack Daniel Jack Daniel         JackDan             Jac                
3   100 Mark        JackDan             Jack Daniel         Jac                
4   103 Mark 2      Mark                Duke                Allan              
5   104 Nike        Nike                Addidas             Puma               
6   104 Reebok      Nike                Puma Nike           Addidas            
7   103 Steve       Duke                Dukes               Allan

Your first join needs `by = "ID"`. OP requires each value in `string_2` to be matched against only values in `string_1` with the same ID. That's why in `df_out` the value "Order" has no nearest match (note that there is no ID 185 in `df_1`). — ekoam, Jan 06 '22 at 09:32

Get nearest n matching strings

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