How to delete (or add) a specific string (or number) in rownames?-CodePudding

For example, given a dataframe rownames:

Patient 01 On
Patient 02 PRE
Patient 03 
Patient 04 PRE

Wanted rownames:

Patient 1 On
Patient 2 PRE
Patient 3
Patient 4 PRE

Or, the other way around, that would also help.

CodePudding user response：

Starting data

           status
patient 01     On
patient 02    PRE
patient 03       
patient 04    PRE

Renaming the rownames

row.names(df) <- df %>%  
  row.names() %>%  
  str_remove_all("0") 

          status
patient 1     On
patient 2    PRE
patient 3       
patient 4    PRE

CodePudding user response：

This will not remove any 0 from 10, for example.

Starting data

dat <- data.frame(a = 1:5)

rownames(dat) <- c("Patient 01 On", "Patient 02 PRE", "Patient 03", "Patient 04 PRE", "Patient 10 PRE")

dat
#>                a
#> Patient 01 On  1
#> Patient 02 PRE 2
#> Patient 03     3
#> Patient 04 PRE 4
#> Patient 10 PRE 5

Substitution

gsub() substitutes anything that matches the pattern in its first argument with its secund argument. The arguments look a bit cryptic because they use regular expressions: in the first one, it means: 0 followed by any digit. The second one means: take the first group in brackets, i.e., the digit that's preceded by a 0.

rownames(dat) <- gsub("0(\\d)", "\\1", rownames(dat))

Output

dat
#>                a
#> Patient 1 On   1
#> Patient 2 PRE  2
#> Patient 3      3
#> Patient 4 PRE  4
#> Patient 10 PRE 5

^{Created on 2022-06-16 by the reprex package (v2.0.1)}