compare-data-frame.md
In waldo: Find Differences Between R Objects

informative diff for additions and deletions

Code
  df <- data.frame(x = 1:5, y = 5:1)
  compare(df, unrowname(df[1:3, ]))
Output
  `attr(old, 'row.names')`: 1 2 3 4 5
  `attr(new, 'row.names')`: 1 2 3

  old vs new
             x y
    old[1, ] 1 5
    old[2, ] 2 4
    old[3, ] 3 3
  - old[4, ] 4 2
  - old[5, ] 5 1

  `old$x`: 1 2 3 4 5
  `new$x`: 1 2 3

  `old$y`: 5 4 3 2 1
  `new$y`: 5 4 3    
Code
  compare(df, unrowname(df[c(1, 5, 2, 3, 4, 5), ]))
Output
  `attr(old, 'row.names')[3:5]`: 3 4 5  
  `attr(new, 'row.names')[3:6]`: 3 4 5 6

  old vs new
             x y
    old[1, ] 1 5
  + new[2, ] 5 1
    old[2, ] 2 4
    old[3, ] 3 3
    old[4, ] 4 2

  `old$x[1:4]`: 1   2 3 4
  `new$x[1:5]`: 1 5 2 3 4

  `old$y[1:4]`: 5   4 3 2
  `new$y[1:5]`: 5 1 4 3 2

informative diff for changes

Code
  df1 <- data.frame(x = 1:3, y = 1, z = c("a", "b", "c"), stringsAsFactors = FALSE)
  df2 <- data.frame(x = c(1, 100, 3), y = 1, z = c("a", "B", "c"),
  stringsAsFactors = FALSE)
  compare(df1, df2)
Output
  old vs new
               x z
    old[1, ]   1 a
  - old[2, ]   2 b
  + new[2, ] 100 B
    old[3, ]   3 c

  `old$x` is an integer vector (1, 2, 3)
  `new$x` is a double vector (1, 100, 3)

  `old$z`: "a" "b" "c"
  `new$z`: "a" "B" "c"

informative diff for rownames

Code
  df1 <- data.frame(x = c(a = 1, b = 2))
  df2 <- data.frame(x = c(a = 1, c = 2))
  compare(df1, df2)
Output
  `attr(old, 'row.names')`: "a" "b"
  `attr(new, 'row.names')`: "a" "c"

converts factors to strings

Code
  compare(df1, df2)
Output
  `levels(old$x)`: "a" "b" "c"
  `levels(new$x)`: "a" "b" "d"

works when nrow(df) > option(max.print)

Code
  withr::local_options(max.print = 1)
  df1 <- data.frame(a = 1:2, b = 1:2)
  df2 <- data.frame(a = c(1, 3), b = 1:2)
  compare(df1, df2)
Output
  old vs new
             a
    old[1, ] 1
  - old[2, ] 2
  + new[2, ] 3

  `old$a` is an integer vector (1, 2)
  `new$a` is a double vector (1, 3)

obeys max_diffs

Code
  df1 <- data.frame(a = 1:5)
  df2 <- data.frame(a = 5:1)
  compare(df1, df2, max_diffs = 3)
Output
  old vs new
             a
  - old[1, ] 1
  + new[1, ] 5
  - old[2, ] 2
  + new[2, ] 4
    old[3, ] 3
  and 2 more ...

  `old$a`: 1 2 3 and 2 more...
  `new$a`: 5 4 3           ...
Code
  compare(df1, df2, max_diffs = 4)
Output
  old vs new
             a
  - old[1, ] 1
  + new[1, ] 5
  - old[2, ] 2
  + new[2, ] 4
    old[3, ] 3
  - old[4, ] 4
  + new[4, ] 2
  and 1 more ...

  `old$a`: 1 2 3 4 and 1 more...
  `new$a`: 5 4 3 2           ...
Code
  compare(df1, df2, max_diffs = 5)
Output
  old vs new
             a
  - old[1, ] 1
  + new[1, ] 5
  - old[2, ] 2
  + new[2, ] 4
    old[3, ] 3
  - old[4, ] 4
  + new[4, ] 2
  - old[5, ] 5
  + new[5, ] 1

  `old$a`: 1 2 3 4 5
  `new$a`: 5 4 3 2 1