R - How to show the real order from 1.1 to 1.12?

Question

In my dataset, there are values from 1.1 to 1.12

R, by default, order them showing 1.10, 1.11 and 1.12 before 1.2.

Example:

## V1  V2
## A   1.1 
## B   1.10
## J   1.11
## K   1.12
## G   1.2
## D   1.3
## E   1.4
## J   1.5
## G   1.6
## T   1.7
## R   1.8
## O   1.9

How can I change the order of V2 ordering the values from 1.1 to 1.12?

(In this way)

## V1  V2
## A   1.1 
## G   1.2
## D   1.3
## E   1.4
## J   1.5
## G   1.6
## T   1.7
## R   1.8
## O   1.9
## B   1.10
## J   1.11
## K   1.12

of course my real dataset is more complex but i belive that a solution for this case could solve my problem

Thanks!

"character"... of course if I use as.numeric it read 1.1 as 1.10 as they are both decimals in the same way. If I use as.integer it delete all decimals... — Silvio Oggioni, Jan 08 '21 at 11:54
Is [this](https://stackoverflow.com/questions/17531403/how-to-sort-a-character-vector-where-elements-contain-letters-and-numbers-in-r) a duplicate? — Rui Barradas, Jan 08 '21 at 11:59
Dunno, that's not my post. Anyway thanks for the solution! ;) — Silvio Oggioni, Jan 08 '21 at 12:22

score 2 · Accepted Answer · answered Jan 08 '21 at 11:54

If the column V2 is of class "character", the following code using function str_order of package stringr will order the data.frame by numeric order of V2.

i <- stringr::str_order(df1$V2, numeric = TRUE)
df1 <- df1[i, ]

df1
#   V1   V2
#1   A  1.1
#5   E  1.2
#6   F  1.3
#7   G  1.4
#8   H  1.5
#9   I  1.6
#10  J  1.7
#11  K  1.8
#12  L  1.9
#2   B 1.10
#3   C 1.11
#4   D 1.12

I have left the row names unordered to show that the entire rows have changed their position, not just column V2. To reset the row names,

row.names(df1) <- NULL

Test data

V1 <- LETTERS[1:12]
V2 <- sprintf("1.%d", 1:12)
V2 <- sort(V2)
df1 <- data.frame(V1, V2)

:D So much more succinct than my snippet. – Mario Niepel Jan 08 '21 at 12:00 — Mario Niepel, Jan 08 '21 at 12:00

score 0 · Answer 2 · answered Jan 08 '21 at 11:58

Here's a tidyverse solution:

library(tidyverse)

data <- data.frame(V1 = LETTERS[seq(1, 20)], V2 = paste0(1, ".", seq(1,20)))
data_sorted <- data %>%
      separate(V2, sep = "\\.", into = c("left", "right"), remove = F) %>%
      arrange(left, right) %>%
      select(-left, -right)

data_sorted
#>    V1   V2
#> 1   A  1.1
#> 2   J 1.10
#> 3   K 1.11
#> 4   L 1.12
#> 5   M 1.13
#> 6   N 1.14
#> 7   O 1.15
#> 8   P 1.16
#> 9   Q 1.17
#> 10  R 1.18
#> 11  S 1.19
#> 12  B  1.2
#> 13  T 1.20
#> 14  C  1.3
#> 15  D  1.4
#> 16  E  1.5
#> 17  F  1.6
#> 18  G  1.7
#> 19  H  1.8
#> 20  I  1.9

^{Created on 2021-01-08 by the reprex package (v0.3.0)}

R - How to show the real order from 1.1 to 1.12?

2 Answers2