From: Manoj <manojsw_at_gmail.com>

Date: Thu 29 Jun 2006 - 12:42:54 EST

# Two data frames with some data

a = data.frame(somedata)

b = data.frame(somedata)

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Thu Jun 29 16:54:51 2006

Date: Thu 29 Jun 2006 - 12:42:54 EST

I am trying to work on writing the following piece of (pseudo) code in an optimal fashion:

# Two data frames with some data

a = data.frame(somedata)

b = data.frame(somedata)

for(i in 1:nrow(dt) {

# Merge dates for a given date into a new data frame
c = merge(a[a$dt==dt[i],),b[b$dt == dt[i],], by=c(some column));
}

Is the following attempt a better way of doing things?

a = data.frame(somedata)

b = data.frame(somedata)

# Pre-allocate data frame c

c = data.frame(for some size);

for(i in 1:nrow(dt) {

# Merge dates for a given date into a new data frame
# and copy the result into c

copy(c, merge(a[a$dt==dt[i],),b[b$dt == dt[i],], by=c(some column));

}

Now the question is, How can I copy the merged data into my pre-allocated data frame c ? I tried rbind/cbind but they are pretty fuzzy about having the right names and dimension hence it fails.

Any help would be greatly appreciated!

Thanks.

Manoj

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Thu Jun 29 16:54:51 2006

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