What is the best way to tidy data and extract numbers (double) from data frame in R?-CodePudding

I have a data frame that contains survey responses. What is the best way to extract the numbers and change them to a double type variable?

Here is a little sample:

a <- ("10.5", "about 30", "25 per month")
tibble(a)

I have tried

parse_double(a)

and it seems like I am close. Any help is appreciated

CodePudding user response：

We need parse_number

library(readr)
parse_number(a)
[1] 10.5 30.0 25.0

The difference is that parse_double works on character vectors with only digits . as the characters whereas parse_number extracts the numeric part from a string which also include non-numeric characters

data

a <- c("10.5", "about 30", "25 per month")

CodePudding user response：

I know a solution too (from base package)

a <- c("10.5", "about 30", "25 per month")
as.numeric(gsub("[[:alpha:]]", "", a)) 


 > as.numeric(gsub("[[:alpha:]]", "", a))
 [1] 10.5 30.0 25.0
 > end_time <- Sys.time()
 > end_time - start_time
 Time difference of 0.01400113 secs
 > start_time <- Sys.time()
 > parse_number(a)
 [1] 10.5 30.0 25.0
 > end_time <- Sys.time()
 > end_time - start_time
 Time difference of 0.1500092 secs

Akrun, my solution is faster ;)))