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.
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.
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
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.
In addition, identical is still useful and supports the practical goal:
identical(a[, "x"], b[, "y"]) # TRUE
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
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
.