Vega 2 Sort

[kanitw]

(part of #459)

• remove sort.js and no longer use sort-<field_name> tables as data source
• modify scale.domain() to include DataRef’s .sort object
• modify sort property to be consistent with Vega 2 (but still leave it as a top-level vega-lite property)
  • sort.name => sort.field
  • sort.aggregate => sort.op
• update tests

[kanitw]

Actually there are still some incorrect cases for movies.json:

A) Dot Plot

{
  "marktype": "point",
  "encoding": {
    "x": {
      "name": "MPAA_Rating",
      "type": "N"
    }
  },
  "data": {
    "url": "data/movies.json"
  }
}

although the output scales looks correct

...
"scales": [
        {
          "name": "x",
          "type": "ordinal",
          "domain": {
            "data": "raw",
            "field": "MPAA_Rating",
            "sort": true
          },
          "range": [0,189],
          "bandWidth": 21,
          "round": true,
          "nice": true,
          "points": true,
          "padding": 1
        }
      ],
...

The output visualization does not order the scale correctly

B) Faceted Small Multiples

{
  "marktype": "point",
  "encoding": {
    "x": {"name": "Rotten_Tomatoes_Rating","type": "Q"},
    "y": {"name": "IMDB_Rating","type": "Q"},
    "col": {"name": "MPAA_Rating","type": "N"}
  },
  "data": {"url": "data/movies.json"}
}

The col scale has sort=true

   {
      "name": "col",
      "type": "ordinal",
      "domain": {"data": "raw","field": "MPAA_Rating","sort": true},
      "bandWidth": 150,
      "round": true,
      "nice": true,
      "padding": 0.1,
      "outerPadding": 0
    }

but the output is not well sorted

[kanitw]

However, similar visualizations from barley.json produces well-sorted output.

A) Dot Plot

{
  "marktype": "point",
  "encoding": {
    "x": {"name": "variety","type": "N"}
  },
  "data": {"url": "data/barley.json"}
}

B) Small Multiple

{
  "marktype": "point",
  "encoding": {
    "x": {"name": "site","type": "N"},
    "y": {"name": "yield","type": "Q"},
    "col": {"axis": {"maxLabelLength": 25},"name": "variety","type": "N"}
  },
  "data": {"url": "data/barley.json"}
}

Not sure what makes things works correctly for barley.json, but not for movies.json

I have inspected barley.json and make sure that the original data is not pre-sorted by variety.

[kanitw]

Actually some variables in movies.json works correctly – for example, Creative_Type works okay.

But some like Major_Genre, MPAA_Rating, Source, Title are broken …

Not sure what makes these sorting incorrect but this sounds more like a bug in lower-level stacks.

[kanitw]

Thanks for merging. I just appended changes to 0.8 branch.