R help - Dec 2004 - String manipulation---mixed case

Hello,

Does anyone know of a "slick" way to get R to convert a string which
is all upper case to a string where the first letter in each word is upper case
and all others are lower case?

I suspect the solution is to begin by parsing the string, convert the
appropriate letters to upper and lower case using "toupper" and
"tolower", and then to paste the pieces back together. Moreover, given
the elegance and power of R, I'll bet this can be coded very tersely. Before
I embarked on trying to code this, I thought I would tap the R braintrust to see
if this has already been done.

Any help greatly appreciated,

Damian  

Damian Betebenner
Educational Research, Measurement & Evaluation
Lynch School of Education
Boston College
Chestnut Hill, MA 02467

(617) 552 4491

Damian Betebenner a ??crit :
> Hello,
> 
> Does anyone know of a "slick" way to get R to convert a string
which
> is all upper case to a string where the first letter in each word is
> upper case and all others are lower case?
> 
> I suspect the solution is to begin by parsing the string, convert the
> appropriate letters to upper and lower case using "toupper" and
> "tolower", and then to paste the pieces back together. Moreover,
> given the elegance and power of R, I'll bet this can be coded very
> tersely. Before I embarked on trying to code this, I thought I would
> tap the R braintrust to see if this has already been done.
> 
> Any help greatly appreciated,
> 
> Damian
> 
> Damian Betebenner Educational Research, Measurement & Evaluation 
> Lynch School of Education Boston College Chestnut Hill, MA 02467
> 
> (617) 552 4491
> 
> ______________________________________________ 
> R-help at stat.math.ethz.ch mailing list 
> https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the
> posting guide! http://www.R-project.org/posting-guide.html
> 
This question was posted a while ago and answered by Christian
Hoffmann. I wrapped it in a small function:

CapLeading <- function (string){
   fn <- function(x){
     v <- unlist(strsplit(x, split = " "))
     u <- sapply(v, function(x){
            x <- tolower(x)
            substring(x, 1, 1) <- toupper(substring(x, 1, 1))
            x})
     paste(u, collapse = " ")
     }
   sapply(string, fn)
   }

Best,

Renaud

-- 
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Damian Betebenner <damian.betebenner <at> bc.edu> writes:

: 
: Hello,
: 
: Does anyone know of a "slick" way to get R to convert a string which
is all
upper case to a string where the first
: letter in each word is upper case and all others are lower case?  
: 
: I suspect the solution is to begin by parsing the string, convert the 
appropriate letters to upper and lower
: case using "toupper" and "tolower", and then to paste the
pieces back
together. Moreover, given the
: elegance and power of R, I'll bet this can be coded very tersely. Before I
embarked on trying to code this, I
: thought I would tap the R braintrust to see if this has already been done.
: 

Assuming x contains your string (or a vector of such strings), try this.
The first iteration replaces each A not following a word boundary 
with a.  The second does the analogous operation with B, etc.

for(L in LETTERS) x <- gsub(paste("\\B", L, sep = ""),
tolower(L), x)