[R] nested if/else very slow, more efficient ways?

[Kim Milferstedt]

Hello,

in the data.frame "resultsfuzzy" I would like to replace the 
characters in the second column ("5a", "5b", ... "5e") with numbers 
from 1 to 5. The data.frame has 39150 entries. I seems to work on 
samples that are << nrow(resultsfuzzy) but it takes suspicously long.

Do you have any suggestions how to make the character replacing more efficient?

Code:

for (i in 1:nrow(resultsfuzzy))
{
if (resultsfuzzy[i,2] == "5a"){resultsfuzzy[i,2] <- 1} else
     if (resultsfuzzy[i,2] == "5b"){resultsfuzzy[i,2] <- 2} else
         if (resultsfuzzy[i,2] == "5c"){resultsfuzzy[i,2] <- 3} else
             if (resultsfuzzy[i,2] == "5d"){resultsfuzzy[i,2] <- 4} else
                 resultsfuzzy[i,2] <- 5
}

Thanks,

Kim

version

platform i386-pc-mingw32
arch     i386
os       mingw32
system   i386, mingw32
status
major    2
minor    2.1
year     2005
month    12
day      20
svn rev  36812
language R

__________________________________________

Kim Milferstedt
University of Illinois at Urbana-Champaign
Department of Civil and Environmental Engineering
4125 Newmark Civil Engineering Laboratory
205 North Mathews Avenue MC-250
Urbana, IL 61801
USA
phone: (001) 217 333-9663
fax: (001) 217 333-6968
email: milferst at uiuc.edu
http://cee.uiuc.edu/research/morgenroth