두 개의 dataframe 비교
https://stackoverflow.com/questions/10592148/compare-if-two-dataframe-objects-in-r-are-equal
a <- data.frame(x = 1:10) b <- data.frame(x = 1:10) all(a==b) # TRUE identical(a,b) # TRUE
## 컬럼명이 같아야 함 a <- data.frame(x = 1:10) b <- data.frame(y = 1:10) all(a==b) # TRUE identical(a,b) # FALSE identical(a[ ,"x"], b[ ,"y"]) # TRUE
## Class가 같아야 함 a <- data.frame(x = 1:10) b <- tbl_df(a) all(a==b) # TRUE identical(a,b) # FALSE
