Count alphabetic to numeric and numeric to alphabetic transitions

Question

I have some data, now I have to count the number of transitions from alphabetic to numeric OR from numeric to alphabetic.

dd <- c(text="S4FDD-S4DF5D_S54F4SDF4","eDC54E_EG5SF3543+TDX32RF","CVB5+5VN7NLC2_3LM70LCM8","1VPLF3LPD5P6OK7POD8KP9OASD9POA0")

Eg. in dd[1]:

S4FDD-S4DF5D_S54F4SDF4 == 6 (Alphabetic to number Count)
                                          & 
                       == 5 (Number to Alphabetic Count)

I tried by using this function, but failed :

stri_count_boundaries(dd, type="character")

`6 alpha to number count, 5 number to alpha count` ... can you explain what exactly this is supposed to mean? — Tim Biegeleisen, Jul 22 '20 at 07:26

ThomasIsCoding · Answer 1 · 2020-07-22T09:46:39.233

3

Here is a base R option using lengths + gregexpr:

> lengths(gregexpr("[[:alpha:]]\\d+",dd))
[1] 6 4 5 8

> lengths(gregexpr("\\d+[[:alpha:]]",dd))
[1] 5 3 4 8

edited Jul 22 '20 at 09:46

answered Jul 22 '20 at 07:59

ThomasIsCoding

96,636
9
24
81

1

There is no need for `regmatches`: `lengths(gregexpr("[[:alpha:]]\\d", dd))` and `lengths(gregexpr("\\d[[:alpha:]]", dd))` will do it already. – GKi Jul 22 '20 at 09:42

score 1 · Answer 2 · answered Jul 22 '20 at 07:29

If I have understood you correctly you want to count how many times you encounter an alphabet followed by a number and vice - versa.

You can use str_count here :

library(stringr)
str_count(dd, '[A-Z]\\d')
#[1] 6 4 5 8

str_count(dd, '\\d[A-Z]')
#[1] 5 3 4 8

Count alphabetic to numeric and numeric to alphabetic transitions

2 Answers2