[R] Applying "toupper" to only portions of text strings

[peter dalgaard]

On May 27, 2011, at 00:05 , Dennis Fisher wrote:

> Colleagues
> 
> Assume that I have a vector containing some text strings, some of which contain a particular character.  I could like to apply "toupper" to the text before the character.  For example (in this case, "|" is the particular character):
> 
> ORIGINAL:
> 	TEXT	<- c("aaaa", "bbb|cc", "|ddd")
> 
> AFTER APPLICATION OF toupper:
> 	TEXT	<- c("AAAA", "BBB|cc", "|dddd")
> 

How are you going to get that extra d in there? >;-)

> I could loop through each element, strsplit at the character, apply toupper to the first component, then paste each element together.  But, I hope that there is a simpler means to accomplish this.

No, I think that is pretty much the plan. It's a one-liner, though:

> sapply(strsplit(TEXT,"|",
fixed=T),function(x){paste(c(toupper(x[1]),x[-1]),collapse="|")})
[1] "AAAA"   "BBB|cc" "|ddd"  


OK, a _long_ one-liner...

-- 
Peter Dalgaard
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com