R help - Sep 2007 - starting with a capital letter

Hi everyone,

I am wondering if there is any built-in funcion that can determine whether
words in a character vector start with a captial letter or not. Help,
please. Thanks.
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kevinchang a ?crit :
> I am wondering if there is any built-in funcion that can determine whether
> words in a character vector start with a captial letter or not. Help,
> please. Thanks.
DIY with tolower().
apply tolower() on 1st letter and compare.

On 15-Sep-07 10:21:19, kevinchang wrote:
> 
> Hi everyone,
> 
> I am wondering if there is any built-in funcion that can
> determine whether words in a character vector start with
> a captial letter or not. Help, please. Thanks.
Something like:

C<-c("Abc", "aBc", "abC")

for(i in (1:length(C))){
 if(length(grep("^[A-Z]",C[i]))>0){
   print("Yes") else print("No")
  }
}


[1] "Yes"
[1] "No"
[1] "No"


The "grep" expression "[A-Z]" looks for one of A,B,C,...,Z
and the "^" makes it look for it at the start of the string.

Hoping this helps,
Ted.

--------------------------------------------------------------------
E-Mail: (Ted Harding) <Ted.Harding at manchester.ac.uk>
Fax-to-email: +44 (0)870 094 0861
Date: 15-Sep-07                                       Time: 12:55:00
------------------------------ XFMail ------------------------------

On Sat, 15 Sep 2007, kevinchang wrote:
>
> Hi everyone,
>
> I am wondering if there is any built-in funcion that can determine whether
> words in a character vector start with a captial letter or not. Help,
> please. Thanks.
Yes. But your query is not precise. See the posting guide and provide 
commented, minimal, self-contained, reproducible code (as is requested) to 
be sure the answers you get address the question you really want answered.

I see several possiblilities.

In this vector:

 	my.charvec<- c( "Abc", "abc Abc", "abc aBc" )

You wish to match element 1 only or 1 and 2 only and perhaps report where 
in each element the last match was found.


 	res <- regexpr( "\\<[[:upper:]].*" , my.charvec )

should get you started. Examples:

 	which( res == 1 ) # first case

 	which( res != -1 ) # second case

See

 	?regexpr

Also,

 	?strsplit

which I think would be needed to recover the locations of each of 
several capitalized words in a single element. e.g. "abc Def Ghi"

Chuck
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>
> ______________________________________________
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> and provide commented, minimal, self-contained, reproducible code.
>
Charles C. Berry                            (858) 534-2098
                                             Dept of Family/Preventive Medicine
E mailto:cberry at tajo.ucsd.edu	            UC San Diego
http://famprevmed.ucsd.edu/faculty/cberry/  La Jolla, San Diego 92093-0901