merging multiple csv files in R using do.call

拟墨画扇 提交于 2019-12-03 11:47:02

merge doesn't accept more than 2 data.frames, so you can't pass it a larger list using do.call:

do.call(merge, list(iris, iris, iris))
#Error in fix.by(by.x, x) : 
#  'by' must specify one or more columns as numbers, names or logical

Use Reduce instead:

Reduce(function(x, y) merge(x, y, by="Species"), list(iris, iris, iris))
#works

do.call accepts a list of all arguments, so try:

my.df <- do.call("merge",append(lapply(csvfiles, read.csv, header = TRUE), list(by=c("date","fx_code")) )
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