Create decimal values of character hex

Question

With the following code I'm reading a text file and displaying one column on the screen.

externalData <- read.delim("testdata.txt", header = FALSE, sep = "@")

i = 1;
while(i < 11) {
  appel <- as.character(externalData[i,3,1])
  i = i + 1;
  print(appel)
}

The output looks like this:

I'm trying to convert these values from hexadecimal to decimal.

I've tried the following:

strtoi(c(appel))

but this doesn't seem to work, this only removes the quotation marks from the first one and the last one, and sets everything in-between to N/A (probably because there are letters in them).

You need to set the argument `base`, i.e. `strtoi("158308", base = 16L)`. — Darren Tsai, Feb 18 '20 at 13:06
Please do not post images for code or data. Also, read the info about [how to ask a good question](https://stackoverflow.com/help/how-to-ask) and how to give a [minimale reproducible example](https://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example/5963610#5963610).That way you can help others to help you! — dario, Feb 18 '20 at 13:06

Darren Tsai · Accepted Answer · 2020-02-18T13:35:05.180

3

Here are 3 ways to convert hexadecimal(character) to decimal(numeric).

x <- c("158308", "bb1787", "853f91")

# 1.
strtoi(x, base = 16L)

# 2.
as.integer(as.hexmode(x))

# 3.
as.integer(paste0("0x", x))
# more general edition:
# as.integer(ifelse(!grepl("^0x", x), paste0("0x", x), x))

edited Feb 18 '20 at 13:35

answered Feb 18 '20 at 13:22

Darren Tsai

32,117
5
21
51

score 2 · Answer 2 · edited Jun 20 '20 at 09:12

From ?strtoi

Convert strings to integers according to the given base using the C function strtol, or choose a suitable base following the C rules.

Arguments

x a character vector, or something coercible to this by as.character.

base an integer which is between 2 and 36 inclusive, or zero (default).

1.Create a reproducible minimal example

appel <- c("158308", "d8db89")

2.Solution using strtoi base argument:

strtoi(appel, base=16)

Returns:

[1]  1409800 14211977

Create decimal values of character hex

2 Answers2