Re: [R] Removing + and ? signs
Jorge Ivan Velez wrote: And if you want to replace both + and ?, here is a suggestion: x - asdf+,jkl? gsub([?]|[+], , x) # [1] asdf,jkl Once you're into character classes ([]), you might as well go all the way: gsub([?+], , x) [1] asdf,jkl -- O__ Peter Dalgaard Øster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~ - (p.dalga...@biostat.ku.dk) FAX: (+45) 35327907 __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Removing + and ? signs
'?' is a metacharacter in a regular expression. You have to escape it: x - asdf+,jkl? gsub(?, , x) Error in gsub(?, , x) : invalid regular expression '?' In addition: Warning message: In gsub(?, , x) : regcomp error: 'Invalid preceding regular expression' # escape it gsub(\\?, , x) [1] asdf+,jkl On Sun, Nov 22, 2009 at 6:01 PM, Steven Kang stochastick...@gmail.com wrote: Hi all, I get an error message when trying to replace *+* or *?* signs (with empty space) from a string. x - asdf+,jkl? gsub(?, , x) Error message: Error in gsub(?, , x) : invalid regular expression '?' In addition: Warning message: In gsub(?, , x) : regcomp error: 'Invalid preceding regular expression' Your expertise in resolving this issue would be appreciated. Thanks. Steven [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve? __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Removing + and ? signs
Try this: gsub([?], , x) On Mon, Nov 23, 2009 at 7:01 AM, Steven Kang stochastick...@gmail.com wrote: Hi all, I get an error message when trying to replace *+* or *?* signs (with empty space) from a string. x - asdf+,jkl? gsub(?, , x) Error message: Error in gsub(?, , x) : invalid regular expression '?' In addition: Warning message: In gsub(?, , x) : regcomp error: 'Invalid preceding regular expression' Your expertise in resolving this issue would be appreciated. Thanks. Steven [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Removing + and ? signs
Dear Steven, You were almost there: x - asdf+,jkl? gsub(\\?, , x) [1] asdf+,jkl gsub(\\+, , x) [1] asdf,jkl? Take a look at the Basic Regular Expressions section in ?regex for more details. HTH, Jorge On Sun, Nov 22, 2009 at 6:01 PM, Steven Kang wrote: Hi all, I get an error message when trying to replace *+* or *?* signs (with empty space) from a string. x - asdf+,jkl? gsub(?, , x) Error message: Error in gsub(?, , x) : invalid regular expression '?' In addition: Warning message: In gsub(?, , x) : regcomp error: 'Invalid preceding regular expression' Your expertise in resolving this issue would be appreciated. Thanks. Steven [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Removing + and ? signs
On 23/11/2009, at 12:01 PM, Steven Kang wrote:
Hi all,
I get an error message when trying to replace *+* or *?* signs
(with empty
space) from a string.
x - asdf+,jkl?
gsub(?, , x)
Error message:
Error in
gsub(?, , x) :
invalid regular expression '?'
In addition: Warning message:
In gsub(?, , x) :
regcomp error: 'Invalid preceding regular expression'
Your expertise in resolving this issue would be appreciated.
(a) That's funny. I don't get an error message when I try your example.
I get
[1] a s d f + , j k l ?
Of course that's not what you want, though.
(b) You need to escape the question mark:
gsub(\\?, , x)
yields
[1] asdf+,jkl
which I think *is* what you want.
cheers,
Rolf Turner
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Re: [R] Removing + and ? signs
And if you want to replace both + and ?, here is a suggestion: x - asdf+,jkl? gsub([?]|[+], , x) # [1] asdf,jkl HTH, Jorge On Sun, Nov 22, 2009 at 6:46 PM, Jorge Ivan Velez wrote: Dear Steven, You were almost there: x - asdf+,jkl? gsub(\\?, , x) [1] asdf+,jkl gsub(\\+, , x) [1] asdf,jkl? Take a look at the Basic Regular Expressions section in ?regex for more details. HTH, Jorge On Sun, Nov 22, 2009 at 6:01 PM, Steven Kang wrote: Hi all, I get an error message when trying to replace *+* or *?* signs (with empty space) from a string. x - asdf+,jkl? gsub(?, , x) Error message: Error in gsub(?, , x) : invalid regular expression '?' In addition: Warning message: In gsub(?, , x) : regcomp error: 'Invalid preceding regular expression' Your expertise in resolving this issue would be appreciated. Thanks. Steven [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Removing + and ? signs
On Nov 22, 2009, at 6:01 PM, Steven Kang wrote: Hi all, I get an error message when trying to replace *+* or *?* signs (with empty space) from a string. x - asdf+,jkl? gsub(?, , x) Since both ? and + are special regex characters, to do both the substitutions at once you need to use double backslashes and an or gsub(\\?|\\+, , x) [1] asdf ,jkl -- David Error message: Error in gsub(?, , x) : invalid regular expression '?' In addition: Warning message: In gsub(?, , x) : regcomp error: 'Invalid preceding regular expression' Your expertise in resolving this issue would be appreciated. Thanks. Steven [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. David Winsemius, MD Heritage Laboratories West Hartford, CT __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
