问题
Suppose I have three dataframes called A1-pre, B3-pos, B4-pre and I want to merge these dataframes. The columns have the same name, so I can use rbind.
newdf <- rbind(A1-pre, B3-pos, B4-pre) #this would work
However, I do not want to manually input all the names of the dataframes myself, I rather use a wildcard for that, so something like
newdf <- rbind(grep(-)) #but this does not work
Any idea how I could do that? Or even better, matching any dataframe named "pre" or "pos" and rbind them all.
回答1:
You can do it with get()
and ls()
:
'A1-pre' <- matrix(rnorm(100), 5)
'B3-pos' <- matrix(rnorm(100), 5)
'B4-pre' <- matrix(rnorm(100), 5)
'C5-not' <- matrix(rnorm(100), 5)
names <- grep('pre|pos$', ls(), value=T)
newDF <- mapply(get, grep('pre|pos$', ls(), value=T))
来源:https://stackoverflow.com/questions/21530779/rbind-dataframes-using-wildcard