[R] extract all numbers from a string

Duncan Mackay mackay at northnet.com.au
Sun Jun 16 07:49:42 CEST 2013




see ?regexpr for information



Duncan Mackay
Department of Agronomy and Soil Science
University of New England
Armidale NSW 2351
Email: home: mackay at northnet.com.au

At 15:06 16/06/2013, you wrote:
>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!
>Nicholas J. Matzke
>Ph.D. Candidate, Graduate Student Researcher
>Huelsenbeck Lab
>Center for Theoretical Evolutionary Genomics
>4151 VLSB (Valley Life Sciences Building)
>Department of Integrative Biology
>University of California, Berkeley
>Graduate Student Instructor, IB200B
>Principles of Phylogenetics: Ecology and Evolution
>Lab websites:
>Dept. personal page: 
>Lab personal page: http://fisher.berkeley.edu/cteg/members/matzke.html
>Lab phone: 510-643-6299
>Dept. fax: 510-643-6264
>Cell phone: 510-301-0179
>Email: matzke at berkeley.edu
>Mailing address:
>Department of Integrative Biology
>1005 Valley Life Sciences Building #3140
>Berkeley, CA 94720-3140
>"[W]hen people thought the earth was flat, they were wrong. When 
>people thought the earth was spherical, they were wrong. But if you 
>think that thinking the earth is spherical is just as wrong as 
>thinking the earth is flat, then your view is wronger than both of 
>them put together."
>Isaac Asimov (1989). "The Relativity of Wrong." The Skeptical 
>Inquirer, 14(1), 35-44. Fall 1989.
>R-help at r-project.org mailing list
>PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>and provide commented, minimal, self-contained, reproducible code.

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