[R] extract all numbers from a string

[arun]

HI,
One way would be:

library(stringr)
tmpstr = "The first number is: 32.  Another one is: 32.1.
Here's a number in scientific format, 0.3523e10, and
another, 0.3523e-10, and a negative, -313.1"
pattern<- "(\\d)+|(\\d+\\.\\d+)|(-\\d+\\.\\d+)|(\\d+.\\d+e\\d+)|(\\d+\\.\\d+e-\\d+)"
str_extract_all(tmpstr,pattern)[[1]]
#[1] "32"         "32.1"       "0.3523e10"  "0.3523e-10" "-313.1"    
 as.numeric(str_extract_all(tmpstr,pattern)[[1]])
A.K.



----- Original Message -----
From: Nick Matzke <matzke at berkeley.edu>
To: R-help at r-project.org
Cc: 
Sent: Sunday, June 16, 2013 1:06 AM
Subject: [R] extract all numbers from a string

Hi all,

I have been beating my head against this problem for a bit, 
but I can't figure it out.

I have a series of strings of variable length, and each will 
have one or more numbers, of varying format.  E.g., I might 
have:


tmpstr = "The first number is: 32.  Another one is: 32.1. 
Here's a number in scientific format, 0.3523e10, and 
another, 0.3523e-10, and a negative, -313.1"

How could I get R to just give me a list of numerics 
containing the numbers therein?

Thanks very much to the regexp wizards!

Cheers,
Nick



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