Hi, I wonder if there's a good intro to the pattern matching using R?
I'm a perl
programer and find it too confusing and complex to use regular expressions under
R.
For instance, why does pmatch("d","ad") returns NULL? How
would I call the
functions in order to match any portion of the string? Under what circumstances
shall
backslush be used? I try to extract all strings with ".d", however
just couldnt manage
to do it? Any ideas? Or I have to write my own regex extension ? TIA.
-Yu
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gopher <radar at orinoco.princeton.edu> writes:> Hi, I wonder if there's a good intro to the pattern matching using R? I'm a perl > programer and find it too confusing and complex to use regular expressions under R. > For instance, why does pmatch("d","ad") returns NULL? How would I call the > functions in order to match any portion of the string? Under what circumstances shall > backslush be used? I try to extract all strings with ".d", however just couldnt manage > to do it? Any ideas? Or I have to write my own regex extension ? TIA. > -YuTry help(regexpr). pmatch does *partial* matching - looks for the string which the first arg is a prefix (well it's really a bit more complicated...) in the same manner as when actual arguments are matched to formals. -- O__ ---- Peter Dalgaard Blegdamsvej 3 c/ /'_ --- Dept. of Biostatistics 2200 Cph. N (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk) FAX: (+45) 35327907 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._