[R] grep for strings

[Charles C. Berry]

On Sun, 5 Dec 2010, Santosh Srinivas wrote:

> I am trying to find the function where I can search for a pattern in a
> text string (I thought I could use grep for this but no :().

Correct, but reading

 	?grep

and running

 	example( grep )

should show you how to do that search.

>
>> x
> [1] "abcdefghijkl"
>
> I want to find the positions (i.e. equivalent of nchar) for "cd" and
> in case there are multiple hits .. then the results as a array

You will need to deal with the possibility that there are more 'cd's in 
some elements of 'text' than in others.

So, it is not obvious that an _array_ will work without some special 
tooling.

HTH,

Chuck



>
> Thank you.
>
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Charles C. Berry                            Dept of Family/Preventive Medicine
cberry at tajo.ucsd.edu			    UC San Diego
http://famprevmed.ucsd.edu/faculty/cberry/  La Jolla, San Diego 92093-0901