Nested data

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Nested data

if (requireNamespace("DiagrammeR", quietly = TRUE)) {
  show <- function(x, ...) DiagrammeR::grViz(gv(x, ...), width = "100%")
}else{
  show <- function(x, ...) cat(d2(x), sep = "\n")
}

While autodb takes a single data frame for input, its data might not be “flat”. As an example, the data might be imported from JSON, using the jsonlite package.

Such nested data frames can be a pain to work with in base R, because many functions aren’t designed to handle them. For example, consider the JSON data below.

[
  {
    "a": 1,
    "b": [1],
    "c": [1, 2],
    "d": [
      [1, 2],
      [3, 4]
    ],
    "e": [1, 2],
    "f": [
      [1, 2],
      [3, 4]
    ],
    "g": [1, 2],
    "h": [[1], [1]],
    "i": {
      "i.1": 1,
      "i.2": "a"
    },
    "k": [
      [1, 4],
      [2, 5],
      [3, 6]
    ],
    "l": [
      [1, 4],
      [2, 5],
      [3, 6]
    ],
    "m": [
      {
        "m.1": 1,
        "m.2": 4
      },
      {
        "m.1": 2,
        "m.2": 5
      },
      {
        "m.1": 3,
        "m.2": 6
      }
    ],
    "n": [
      {
        "n.1": 1,
        "n.2": 4
      },
      {
        "n.1": 2,
        "n.2": 5
      },
      {
        "n.1": 3,
        "n.2": 6
      }
    ]
  },
  {
    "a": 2,
    "b": [2, 3],
    "c": [3, 4],
    "d": [
      [5, 6],
      [7, 8]
    ],
    "e": [1, 2],
    "f": [
      [5, 6],
      [7, 8]
    ],
    "g": [2, 1],
    "h": [[2], [2]],
    "i": {
      "i.1": 2,
      "i.2": "b"
    },
    "k": [
      [1, 4],
      [2, 5],
      [3, 6]
    ],
    "l": [
      [1, 4],
      [2, 5],
      [3, 6]
    ],
    "m": [
      {
        "m.1": 1,
        "m.2": 4
      },
      {
        "m.1": 2,
        "m.2": 5
      },
      {
        "m.1": 3,
        "m.2": 6
      }
    ],
    "n": [
      {
        "n.1": 1,
        "n.2": 4
      },
      {
        "n.1": 2,
        "n.2": 5
      },
      {
        "n.1": 3,
        "n.2": 6
      }
    ]
  },
  {
    "a": 3,
    "b": [4, 5, 6],
    "c": [5, 6],
    "d": [
      [9, 10],
      [11, 12]
    ],
    "e": ["a", "b"],
    "f": [
      [9, 10],
      [11, 12]
    ],
    "g": [1, 2],
    "h": [[1], [1]],
    "i": {
      "i.1": 3,
      "i.2": "c"
    },
    "k": [
      [1, 4],
      [2, 5],
      [3, 6]
    ],
    "l": [
      [1, 4],
      [2, 5],
      [3, 6]
    ],
    "m": [
      {
        "m.1": 1,
        "m.2": 4
      },
      {
        "m.1": 2,
        "m.2": 5
      },
      {
        "m.1": 3,
        "m.2": 6
      }
    ],
    "n": [
      {
        "n.1": 1,
        "n.2": 4
      },
      {
        "n.1": 2,
        "n.2": 5
      },
      {
        "n.1": 3,
        "n.2": 6
      }
    ]
  },
  {
    "a": 4,
    "b": [1],
    "c": [3, 4],
    "d": [
      [9, 10],
      [11, 12]
    ],
    "e": [
      ["a"],
      ["b", "c"]
    ],
    "f": [
      [9, 10]
    ],
    "g": [2, 1],
    "h": [[3], [3]],
    "i": {
      "i.1": 4,
      "i.2": "d"
    },
    "k": [
      [1, 6],
      [2, 7],
      [3, 8],
      [4, 9],
      [5, 10]
    ],
    "l": [
      [7, 10],
      [8, 11],
      [9, 12]
    ],
    "m": [
      {
        "m.1": 1,
        "m.2": 6
      },
      {
        "m.1": 2,
        "m.2": 7
      },
      {
        "m.1": 3,
        "m.2": 8
      },
      {
        "m.1": 4,
        "m.2": 9
      },
      {
        "m.1": 5,
        "m.2": 10
      }
    ],
    "n": [
      {
        "n.1": 7,
        "n.2": 10
      },
      {
        "n.1": 8,
        "n.2": 11
      },
      {
        "n.1": 9,
        "n.2": 12
      }
    ]
  },
  {
    "a": 5,
    "b": [2, 3],
    "c": [3, 4],
    "d": [
      [9, 10],
      [11, 12]
    ],
    "e": [
      ["a"],
      ["b", "c"]
    ],
    "f": [
      [9, 10]
    ],
    "g": [1, 2],
    "h": [[2], [2]],
    "i": {
      "i.1": 5,
      "i.2": "e"
    },
    "k": [
      [1, 6],
      [2, 7],
      [3, 8],
      [4, 9],
      [5, 10]
    ],
    "l": [
      [7, 10],
      [8, 11],
      [9, 12]
    ],
    "m": [
      {
        "m.1": 1,
        "m.2": 6
      },
      {
        "m.1": 2,
        "m.2": 7
      },
      {
        "m.1": 3,
        "m.2": 8
      },
      {
        "m.1": 4,
        "m.2": 9
      },
      {
        "m.1": 5,
        "m.2": 10
      }
    ],
    "n": [
      {
        "n.1": 7,
        "n.2": 10
      },
      {
        "n.1": 8,
        "n.2": 11
      },
      {
        "n.1": 9,
        "n.2": 12
      }
    ]
  }
]

x <- jsonlite::fromJSON(js)
x

print(tibble::as_tibble(x), width = Inf)

autodb has some ability to deal with nested data: specifically, where columns contain lists, data frames, or matrices. When plotting, column classes are described with any common nested class information within angle brackets (<>), and common dimensions are given within square brackets ([]):

The first dimension isn’t at the top level, since the number of rows is already given in the table’s header. For example, column i is a data frame, so has the same number of rows as the main data frame: the size information only gives its column count.

nest_level can be set to limit how deeply nested the given class information can be:

show(x, nest_level = 0)

db <- autodb(x)
show(db)

Also as expected, rejoining the resulting database into a single data frame gives back the original:

y <- rejoin(db)
df_equiv(y, x)

These binaries (installable software) and packages are in development.
They may not be fully stable and should be used with caution. We make no claims about them.