Hi: I am a new R user. I have the following question and would appreciate your input Data1 (data frame 1) p1,d1,d2 (p1 is text and d1 and d2 are numeric) xyz,10,25 Data2 (data frame 2) p1,d1,d2 xyz,11,15 Now I want to create a new data frame that looks like so below. The fields d1 and s2 are summed by the product key. Data3 p1,d1,d2 xyz,21 (sum of 10 from Data1 and 11 from Data2),40 (sum of 25 from Data1 and 15 from Data2) Any other examples of merge you may have will be appreciated. Thanks. Satish
Merge question
3 messages · Vadlamani, Subrahmanyam {FLNA}, milton ruser, Marc Schwartz
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on 02/26/2009 11:52 AM Vadlamani, Subrahmanyam {FLNA} wrote:
Hi: I am a new R user. I have the following question and would appreciate your input Data1 (data frame 1) p1,d1,d2 (p1 is text and d1 and d2 are numeric) xyz,10,25 Data2 (data frame 2) p1,d1,d2 xyz,11,15 Now I want to create a new data frame that looks like so below. The fields d1 and s2 are summed by the product key. Data3 p1,d1,d2 xyz,21 (sum of 10 from Data1 and 11 from Data2),40 (sum of 25 from Data1 and 15 from Data2) Any other examples of merge you may have will be appreciated. Thanks. Satish
Given the nature of your data, having the same column structure with repeated keys, I would not use merge(), but rbind() the two data frames together and then use aggregate(): DF <- rbind(Data1, Data2)
DF
p1 d1 d2 1 xyz 10 25 2 xyz 11 15
aggregate(DF[-1], list(p1 = DF$p1), sum)
p1 d1 d2
1 xyz 21 40
See ?rbind and ?aggregate
If you search the list archives:
RSiteSearch("merge")
you will yield hundreds of posts showing the use of that particular
function.
HTH,
Marc Schwartz