Error when unequal number of rows

[maciejmotyka]

I'm looking for a way to find mismatches between two data frames that may have an unequal number of rows. Something along the lines you might get from running anti_join(df1, df2) followed by anti_join(df2, df1). I hoped that dataCompareR would do this, but apparently it's not possible.

df2 <- tibble(col1 = c("cat", "dog", "mouse", "fly"))
df1 <- tibble(col1 = c("cat", "dog", "rat"))
dataCompareR::rCompare(df1, df2)
Running rCompare...
Coercing input data to data.frame
Error in (nrow(df_a_subset) + 1):nrow(df_a) : argument of length 0

What do you think about adding this functionality to dataCompareR?
Or maybe I'm missing some other obvious way to do this kind of comparison?

[robne1982]

It looks like this is actually a bug with single column dataframes. What you're trying to do is exactly what the package is intended to be used for.

If you add a second column

df1 <- tibble(col1 = c("cat", "dog", "rat"), col2 = c(1, 2, 3))
df2 <- tibble(col1 = c("cat", "dog", "mouse", "fly"), col2 = c(1, 2, 3, 4))

dataCompareR::rCompare(df1, df2)

Running rCompare...
Coercing input data to data.frame
All columns were compared, 1 row(s) were dropped from comparison
There are  1 mismatched variables:
First and last 5 observations for the  1 mismatched variables
  rowNo valueA valueB variable  typeA  typeB diffAB
1     3    rat  mouse     COL1 factor factor   

I'm no longer directly involved in this project. but I'll take a look as it should be an easy fix.

In the meantime, you can work around this issue for single column dataframes by adding a second dummy column to both dataframes.