[R] Extracting numbers from a character variable of different types
David Winsemius
dwinsemius at comcast.net
Sun Mar 18 16:37:24 CET 2012
On Mar 18, 2012, at 10:44 AM, irene wrote:
> Hello,
>
> I have a file which contains a column with age, which is represented
> in the
> two following patterns
>
> 1. "007/A" or ''007/a" or ''7 /a" ..... In this case A or a means
> year and I
> would like to extract only the numeric values eg 7 in the above case
> if this
> pattern exits in a line of file.
>
> 2. "004/M" or "004/m" where M or m means month ...... for these
> lines I
> would like to first extract the numeric value of Month eg. 4 and then
> convert it into a value of years, which would be 0.33 eg 4 divided
> by 12.
I thought it easier to get to months as an initial step:
> dfrm <- read.table(text="'007/A'\n'007/a' \n '7 /a '\n '004/
M'\n'004/m'")
> dfrm$agenew <- sub("(^\\d+\\s*)(/)([aA])","\\1 * 12", dfrm$V1)
> dfrm$agenew2 <- sub("(^\\d+\\s*)(/)([mM])","\\1", dfrm$agenew)
> dfrm$agenew2
[1] "007 * 12" "007 * 12" "7 * 12 " "004" "004"
> eval(parse(text=dfrm$agenew2))
[1] 4
> sapply(dfrm$agenew2, function(x) eval(parse(text=x)) )
007 * 12 007 * 12 7 * 12 004 004
84 84 84 4 4
>
> Can anyone help?
>
> Thank you
>
> --
> View this message in context: http://r.789695.n4.nabble.com/Extracting-numbers-from-a-character-variable-of-different-types-tp4482248p4482248.html
> Sent from the R help mailing list archive at Nabble.com.
>
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David Winsemius, MD
West Hartford, CT
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