on 06/12/2008 03:46 PM Hua Li wrote:
Hi,
I'm looking for some way to pick up the numbers which are contained and buried in a long character.
For example,
outtree.new="(((B:1204.25,E:1204.25):7581.11,F:8785.36):8353.85,C:17139.21);"
num.char =
unlist(strsplit(unlist(strsplit(unlist(strsplit(unlist(strsplit(unlist(strsplit(outtree.new,")",fixed=TRUE)),"(",fixed=TRUE)),":",fixed=TRUE)),",",fixed=TRUE)),";",fixed=TRUE))
num.vec=as.numeric(num.char[1:(length(num.char)-1)])
num.char
# "B" "1204.25" "E" "1204.25" "7581.11" "F" "8785.36" "8353.85" "C" "17139.21" ""
num.vec
# NA 1204.25 NA 1204.25 7581.11 NA 8785.36 8353.85 NA
17139.21
would help me get the numbers such as 1204.25, 7581.11, etc, but with a warning
message which reads:
"Warning message:
NAs introduced by coercion "
Is there a way to get around this? Thanks!
Hua
Your code above is overly and needlessly complicated, which makes it
difficult to debug.
I would take an approach whereby you use gsub() to strip non-numeric
characters from the input character vector and then use scan() to read
the remaining numbers:
> Vec <- scan(textConnection(gsub("[^0-9\\.]+", " ", outtree.new)))
Read 6 items
> Vec
[1] 1204.25 1204.25 7581.11 8785.36 8353.85 17139.21
> str(Vec)
num [1:6] 1204 1204 7581 8785 8354 ...
The result of using gsub() above is:
> gsub("[^0-9\\.]+", " ", outtree.new)
[1] " 1204.25 1204.25 7581.11 8785.36 8353.85 17139.21 "
That gives you a character vector which can then be passed to scan() as
a textConnection().
See ?gsub, ?regex, ?textConnection and ?scan for more information.
HTH,
Marc Schwartz
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