how to add two data.frame with the same column but different row numbers
Hi: Here's one approach:
df1 <- data.frame(x = letters[1:3], y = 1:3)
df2 <- data.frame(x = c('a', 'c'), z = c(6, 1))
dfm <- merge(df1, df2, all.x = TRUE)
dfm
x y z 1 a 1 6 2 b 2 NA 3 c 3 1 sumdf <- data.frame(x = dfm$x, y = rowSums(dfm[, -1], na.rm = TRUE)) x y 1 a 7 2 b 2 3 c 4 HTH, Dennis
On Fri, Apr 15, 2011 at 1:31 PM, zhenjiang xu <zhenjiang.xu at gmail.com> wrote:
Hi all, Suppose I have 2 data.frame , a and b, how can I add them together to get c? Thanks
a
?A a 1 b 2 c 3
b
?A a 6 c 1
c
? A a 7 b 2 c 4 -- Best, Zhenjiang ? ? ? ?[[alternative HTML version deleted]]
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