Compare if two dataframe objects in R are equal?

Question

How do I check if two objects, e.g. dataframes, are value equal in R?

By value equal, I mean the value of each row of each column of one dataframe is equal to the value of the corresponding row and column in the second dataframe.

`?all.equal` or `?identical`? If its not those two then you'll have to expand on your question so we know what exactly you're trying to compare. — Justin, May 14 '12 at 23:03
Have a look [HERE](http://stackoverflow.com/questions/3395696/difference-in-r-between-identicalx-y-and-istrueall-equalx-y) — Tyler Rinker, May 14 '12 at 23:33
I voted to close because it is too vague to answer in its current state. — IRTFM, May 15 '12 at 00:32

David LeBauer · Accepted Answer · 2012-07-19T13:27:39.250

63

It is not clear what it means to test if two data frames are "value equal" but to test if the values are the same, here is an example of two non-identical dataframes with equal values:

a <- data.frame(x = 1:10)
b <- data.frame(y = 1:10)

To test if all values are equal:

all(a == b) # TRUE

To test if objects are identical (they are not, they have different column names):

identical(a,b) # FALSE: class, colnames, rownames must all match.

edited Jul 19 '12 at 13:27

answered May 14 '12 at 23:50

David LeBauer

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In case anyone's confused, they aren't identical because the column names aren't the same. – joran May 15 '12 at 00:04
1

@joran thanks for pointing that out, I have clarified my answer. – David LeBauer May 15 '12 at 00:26
2

Note that for `identical` to return true not just values and column names must match, but row numbers/names too. (This hit me when using subset(); it turned out `all` was what I wanted.) – Darren Cook Jul 19 '12 at 09:08
@DavidLeBauer is there a way to make identical ignore the order? – Herman Toothrot Aug 25 '16 at 13:47
@user4050 the order of what? the order of values? You could sort both vectors like `identical(sort(a), sort(b))`. – Abe Aug 26 '16 at 17:38

score 14 · Answer 2 · answered Feb 27 '14 at 04:09

14

In addition, identical is still useful and supports the practical goal:

identical(a[, "x"], b[, "y"]) # TRUE

answered Feb 27 '14 at 04:09

Brad Horn

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milan · Answer 3 · 2016-06-19T20:47:50.223

We can use the R package compare to test whether the names of the object and the values are the same, in just one step.

a <- data.frame(x = 1:10)
b <- data.frame(y = 1:10)

library(compare)
compare(a, b)
#FALSE [TRUE]#objects are not identical (different names), but values are the same.

In case we only care about equality of the values, we can set ignoreNames=TRUE

compare(a, b, ignoreNames=T)
#TRUE
#  dropped names

The package has additional interesting functions such as compareEqual and compareIdentical.

score 0 · Answer 4 · answered Nov 11 '20 at 12:37

Without the need to rely on another package, but to compare structure (class and attributes) of two data sets:

structure_df1 <- sapply(df1, function(x) paste(class(x), attributes(x), collapse = ""))
structure_df2 <- sapply(df2, function(x) paste(class(x), attributes(x), collapse = ""))

all(structure_df1 == structure_df2)

Compare if two dataframe objects in R are equal?

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