CODEWITHSUNDEEP
rstringvectorcharacternumeric
Richard
Richard

Reputation: 497

How to change character to numeric vector in R

Given a, I have to return b:

a <- "[1, 2, 3]"   # class: character
b <- c(1, 2, 3)    # class: numeric

I have tried strsplit() and paste() functions but both are not working well. Can I get some help?

Upvotes: 2

Views: 544

Answers (4)

IRTFM
IRTFM

Reputation: 263301

I'm guessing that this is from a JSON source, so there are packages for that:

 library(jsonlite) # obviously needs to be installed first

fromJSON(a)
#[1] 1 2 3

JSON files always are read into R functions from type character but the converted to R objects with typing conventions like that of read.table.

Upvotes: 3

AnilGoyal
AnilGoyal

Reputation: 26218

stringr (tidyverse) way of doing it

library(stringr)
a <- "[1, 2, 3]"

str_split(a, ',') %>% unlist %>%
  str_replace('\\D*(\\d*)\\D*', '\\1') %>%
  as.numeric()
#> [1] 1 2 3

Created on 2021-06-27 by the reprex package (v2.0.0)

Upvotes: 0

Tim Biegeleisen
Tim Biegeleisen

Reputation: 520898

I prefer to do a regex find all to extract all digits. Then, cast the character vector output to numeric:

a <- "[1, 2, 3]"
b <- as.numeric(regmatches(a, gregexpr("[0-9]+", a))[[1]])
b

[1] 1 2 3

Upvotes: 1

Ronak Shah
Ronak Shah

Reputation: 388807

Clean the string with gsub, split it on comma and convert it to numeric.

b <- as.numeric(unlist(strsplit(gsub('\\[|\\]', '', a), ',\\s+')))
b
#[1] 1 2 3

Upvotes: 1

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