Pfthb

I am attempting to find the n best matches of some text strings, via levenshtein distance (adist in R). The following example should clarify:

name <- c("holiday inn", "geico", "zgf", "morton phillips")
address <- c("400 lafayette pl tupelo ms", "227 geico plaza chevy chase md", 
 "811 quincy st washington dc", "1911 1st st rockville md")

source1 <- data.frame(name, address)

 name <- c("williams sonoma", "mamas bbq", "davis polk", "hop a long diner","joes crag shack", "mike lowry place", "holiday inn", "zummer")

name2 <- c(NA, NA, NA, NA, NA, NA, "hi express", "zummer gunsul frasca")
address <- c("2 reads way new castle de", "248 w 4th st newark de",
 "1100 21st st nw washington dc", "1804 w 5th st wilmington de",
 "1208 kenwood parkway holdridge nb", "4203 ocean drive miami fl",
 "400 lafayette pl tupelo ms", "811 quincy st washington dc")
source2 <- data.frame(name, name2, address)

The following calculates the edit distance using address and name.

dist.mat.nm <- adist(source1$name, source2$name, partial = T, ignore.case = TRUE)
dist.mat.ad <- adist(source1$address, source2$address, partial = TRUE, ignore.case = TRUE)

The following returns the five best matches, each in a column.

imat <- apply(dist.mat.nm, 1, order)[1:5, ]
top.nm <- data.frame(name = source1$name)
tmp <- apply(imat, 1, function(i) source2$name[i])
colnames(tmp) <- paste("top", 1:5, sep = ".")
top.nm <- cbind(top.nm, tmp)

imat <- apply(dist.mat.ad, 1, order)[1:5, ]
top.ad <- data.frame(address = source1$address)
tmp <- apply(imat, 1, function(i) source2$address[i])
colnames(tmp) <- paste("top", 1:5, sep = ".")
top.ad <- cbind(top.ad, tmp)

What I would like to do is:

1. For each "top.name" and "top.ad" column, return the row index where the match came from. (I imagine something using which and grepl would be best because but I am open to suggestions.)


2. Return the value of adist in another column.

The desired result is, for each top.ad, top.nm column, a corresponding index.match column and a distance column containing the value of adist.

For example, the row indexes for top.name.1 are c(7, 6, 4, 1).

Any help would be much appreciated. Thanks.

UPDATE: I found that the following code provides the row index for the first match, but I would like to be able to use vectors for x and y:

find.index <- function(x, y) return(which(grepl(paste(x, collapse = "|"), y, fixed = F)))
vec <- find.index(source1$name, source2$name)

How would I return a whole vector?