Get last number out of a cell with multiple numbers-CodePudding

I have a datatable in R with a column that contains multiple values separated by a comma and I would like to extract the last value from each row in that column. However, the number of values in the different rows vary. Some times there are 3 or 4 values separated by commas and sometimes there is only one. I always need the last value.

The rows look basically like this.

[1.848]     
[0.207,0.403]   
[0.3,0.29]      
[0.948,3.064]       
[0.431,0.431,0.214] 
[0.305,0.305,0.30]  
[0.213,0.42]    
[0.31,0.30]     
[1.484,2.433]

That would be my preferred outcome:

Maybe someone as an idea on how to solve that in R.

Thanks a lot!

CodePudding user response：

Here a solution that I use , as reference to get the last number.

library(dplyr)
library(stringr)
    
x <- c("1.848", "0.207,0.403", "0.3,0.29", "0.948,3.064", "0.431,0.431,0.214", 
       "0.305,0.305,0.30", "0.213,0.42", "0.31,0.30", "1.484,2.433")
    
df <- tibble(x = x)

last_number <- function(x){
  as.numeric(word(x,str_count(x,",")   1,sep = ","))
}

df %>% 
  mutate(last_number = last_number(x))

# A tibble: 9 x 2
  x                 last_number
  <chr>                   <dbl>
1 1.848                   1.85 
2 0.207,0.403             0.403
3 0.3,0.29                0.29 
4 0.948,3.064             3.06 
5 0.431,0.431,0.214       0.214
6 0.305,0.305,0.30        0.3  
7 0.213,0.42              0.42 
8 0.31,0.30               0.3  
9 1.484,2.433             2.43

CodePudding user response：

We may use trimws from base R

df1$col1 <- as.numeric(trimws(df1$col1, whitespace = ".*,|[][]"))

-output

data

df1 <- structure(list(col1 = c("[1.848]", "[0.207,0.403]", "[0.3,0.29]", 
"[0.948,3.064]", "[0.431,0.431,0.214]", "[0.305,0.305,0.30]", 
"[0.213,0.42]", "[0.31,0.30]", "[1.484,2.433]")), 
class = "data.frame", row.names = c(NA, 
-9L))