R: combine summary of multiple csv files into one data frame

问题

I have a directory with many csv files. I want to read them into then create a summary of a column into one data frame.

getSummary<-function(df){
   summary(df$Names)
}

filenames<-list.files(path, pattern="*.csv", full.names=T)
ldf<-lapply(filenames, read.csv, header=T)
results<-lapply(ldf, getSummary)

It is returning results as follows:

print(results)
[[1]]  a   b   c  d
      100  2   3  4
[[2]]  a   b   c  d
      97   4   2  6

What I want is something like this

filename  a   b   c   d
1.csv    100  2   3   4
2.csv     97  4   2   6

Can someone help??

Thanks.

回答1:

I think you probably want do.call(rbind,results). But that will only work if each component has at least one of each letter (i.e. all the columns must be present in each). If not you could use rbind.fill from plyr instead.

I'd also suggest that table is a safer function to be using for this purpose than summary.

来源：https://stackoverflow.com/questions/16984529/r-combine-summary-of-multiple-csv-files-into-one-data-frame