[R] Odp: Exact String Compare in R?

[Petr PIKAL]

Hi

what about

D2[,1] %in% D1[,1]

Regards
Petr

r-help-bounces at r-project.org napsal dne 03.11.2009 14:41:02:

> 
> Dear R users:
> Here's a barebones example of what I can't make work. 
> As you can see, regexpr() does not perform an exact string match, which 
only
> occurs in row 1 of these data frames. Instead, as it's supposed to do, 
it
> finds "b" in "bb" and "c" in "cc". Does anybody know what function I can 
use
> such that only the first rows would be matched (ie, exact string match?)
> I've also tried simply using the == operator, in which case i get the
> error:"level sets of factors are different"
> 
> Thank you in advance, 
> B
> 
> > ## two toy data frames, containing character arrays
> > D1=as.data.frame(c("a","b","c"))
> > D2=as.data.frame(c("a","bb","cc"))
> > 
> > ## loop through each comparing the strings in each row
> > i=1 #counter
> > while (regexpr(D1[i,1], D2[i,1]) == TRUE) {
> +        cat("identical match on row #", i, "\n")
> +        i=i+1 
> +         if (i>3) break 
> + }
> identical match on row # 1 
> identical match on row # 2 
> identical match on row # 3 
> -- 
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> R--tp26160122p26160122.html
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> 
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