Compare two data frames

compare() creates a representation of the differences between two tables, along with a shallow copy of the tables. This output is used as the comparison argument when exploring the differences further with other versus functions e.g. slice_*() and weave_*().

Usage

compare(table_a, table_b, by, allow_both_NA = TRUE, coerce = TRUE)

Arguments

table_a

A data frame

table_b

A data frame

by

<tidy-select>. Selection of columns to use when matching rows between .data_a and .data_b. Both data frames must be unique on by.

allow_both_NA

Logical. If TRUE a missing value in both data frames is considered as equal

coerce

Logical. If FALSE and columns from the input tables have differing classes, the function throws an error.

Value

compare()

A list of data frames having the following elements:

tables

A data frame with one row per input table showing the number of rows and columns in each.

by

A data frame with one row per by column showing the class of the column in each of the input tables.

intersection

A data frame with one row per column common to table_a and table_b and columns "n_diffs" showing the number of values which are different between the two tables, "class_a"/"class_b" the class of the column in each table, and "value_diffs" a (nested) data frame showing the the row indices with differing values

unmatched_cols

A data frame with one row per column which is in one input table but not the other and columns "table": which table the column appears in, "column": the name of the column, and "class": the class of the column.

unmatched_rows

A data frame which, for each row present in one input table but not the other, contains the column "table" showing which table the row appears in and the by columns for that row.

data.table inputs

If the input is a data.table, you may want compare() to make a deep copy instead of a shallow copy so that future changes to the table don't affect the comparison. To achieve this, you can set options(versus.copy_data_table = TRUE).

Examples

compare(example_df_a, example_df_b, by = car)
#> $tables
#> # A tibble: 2 × 4
#>   table   expr          nrow  ncol
#>   <chr>   <chr>        <int> <int>
#> 1 table_a example_df_a     9     9
#> 2 table_b example_df_b    10     9
#> 
#> $by
#> # A tibble: 1 × 3
#>   column class_a   class_b  
#>   <chr>  <chr>     <chr>    
#> 1 car    character character
#> 
#> $intersection
#> # A tibble: 7 × 5
#>   column n_diffs class_a class_b diff_rows       
#>   <chr>    <int> <chr>   <chr>   <list>          
#> 1 mpg          2 numeric numeric <tibble [2 × 2]>
#> 2 cyl          0 integer integer <tibble [0 × 2]>
#> 3 disp         2 numeric numeric <tibble [2 × 2]>
#> 4 hp           0 integer integer <tibble [0 × 2]>
#> 5 drat         0 numeric numeric <tibble [0 × 2]>
#> 6 wt           0 numeric numeric <tibble [0 × 2]>
#> 7 vs           0 integer integer <tibble [0 × 2]>
#> 
#> $unmatched_cols
#> # A tibble: 2 × 2
#>   table column
#>   <chr> <chr> 
#> 1 a     am    
#> 2 b     carb  
#> 
#> $unmatched_rows
#> # A tibble: 3 × 3
#>   table car          row
#>   <chr> <chr>      <int>
#> 1 a     Mazda RX4      7
#> 2 b     Merc 280C      5
#> 3 b     Merc 450SE     8
#>