
On Dec 1, 2009, at 3:28 PM, Gabor Grothendieck wrote:

> Try this:
>
> > library(gsubfn)
> > strapply(testvec, "[-+.0-9]+", as.numeric, simplify = ~  
> colMeans(cbind(...)))
> [1] -5.8500 -2.9800 -2.8160 -2.7120 -2.6325 -2.5680

Very, nice. Also tried on some other valid ("200,2") and  
invalid )"2..2") numbers as it has worked as expected. It did not  
accept "--2.597" but that hardly seems to be a plausible result from a  
cut operation.

-- 
David.

>
>
> On Tue, Dec 1, 2009 at 3:14 PM, David Winsemius <dwinsemius@comcast.net 
> > wrote:
> I'm sitting here chuckling. Your solution is just so "pure".
>
> I would offer an enhancement. When I tested with my cuts that had  
> "-" before the digits, you solution dropped them, so my suggestion  
> for the pattern would be:   "[-[:digit:].]+"
>
> I will admit that I thought it might fail with positive numbers but  
> it does not seem to:
>
> > interv <- strapply(testvec, "[-[:digit:].]+", as.numeric, simplify  
> = TRUE)
> > interv
>       [,1]     [,2]   [,3]   [,4]   [,5]   [,6]   [,7]    [,8]   [, 
> 9] [,10]
> [1,] -8.616   -3.084 -2.876 -2.756 -2.668 -2.597 -1.008 -1.0000  
> 0.9914 1.000
> [2,] -3.084   -2.876 -2.756 -2.668 -2.597 -2.539 -1.000 -0.9922  
> 1.0000 1.009
>
> I was not able to get that pattern to give acceptable results in  
> gsubfn, so I obviously need to study this more closely.
>
> -- 
> David.
>
>
> On Dec 1, 2009, at 2:47 PM, Gabor Grothendieck wrote:
>
> You also might want to look at
>
> demo("gsubfn-cut")
>
>
> On Tue, Dec 1, 2009 at 2:41 PM, David Winsemius <dwinsemius@comcast.net 
> > wrote:
> Starting with the head of a 499 element matrix whose column names  
> are now the labels trom a cut() operation, I needed to get to a  
> vector of midpoints to serve as the basis for plotting a calibration  
> curve ( exp(linear predictor) vs.  :
>
> > dput(head(dimnames(mtcal)[2][[1]])) # was starting point
>
>
> testvec <- c("(-8.616,-3.084]", "(-3.084,-2.876]",  
> "(-2.876,-2.756]", "(-2.756,-2.668]",
> "(-2.668,-2.597]", "(-2.597,-2.539]")
>
> I started this message with the thought of requesting an answer but  
> kept asking myself if I really had check the docs and tested my  
> understanding. I eventually solved it using the gsubfn from the  
> gsubfn package:
>
> testintvl <-as.numeric(gsubfn("\\((-?[[:digit:]]+.?[[:digit:]]*),
> (-?[[:digit:]]+.?[[:digit:]]*)\\]",
> ~ (as.numeric(x)+as.numeric(y))/2,  testvec))
>
> # I did discover that carriage returns in the middle of the pattern  
> will not give desired results, so if this is broken by your mail- 
> client, be sure to rejoin in the console.
>
> The extra "?"'s after the decimal point are in there because I had 4  
> NA's around the median linear predictor:
>
> > dimnames(mtcal)[2][[1]][which(is.na(testintvl))]
> [1] "(-1.008,-1]"  "(-1,-0.9922]" "(0.9914,1]"   "(1,1.009]"
>
> So a better test vector would be:
>
> testvec <- c("(-8.616,-3.084]", "(-3.084,-2.876]",  
> "(-2.876,-2.756]", "(-2.756,-2.668]",
> "(-2.668,-2.597]", "(-2.597,-2.539]", "(-1.008,-1]",   
> "(-1,-0.9922]", "(0.9914,1]", "(1,1.009]" )
>
> > testintvl <-as.numeric(gsubfn("\\((-?[[:digit:]]+.?[[:digit:]]*), 
> (-?[[:digit:]]+.?[[:digit:]]*)\\]",
> + ~ (as.numeric(x)+as.numeric(y))/2,  testvec))
>
> > testintvl
>  [1] -5.8500 -2.9800 -2.8160 -2.7120 -2.6325 -2.5680 -1.0040  
> -0.9961  0.9957  1.0045
>
> I offer this to those who may feel regex challenged (as I often do).  
> The gsubfn function is pretty slick. I don't see an author listed  
> for the function, but the author of the package documents is Gabor  
> Grothendieck.
>
> --
>
> 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.
>
>
> David Winsemius, MD
> Heritage Laboratories
> West Hartford, CT
>
>

David Winsemius, MD
Heritage Laboratories
West Hartford, CT


	[[alternative HTML version deleted]]


