Class: RailsDataExplorer::Chart::Scatterplot

Inherits:
RailsDataExplorer::Chart show all
Defined in:
lib/rails_data_explorer/chart/scatterplot.rb

Overview

Responsibilities:

* Render a scatter plot for either
    * bivariate analysis of two quantitative data series or
    * multivariate analysis of two quantitative and one categorical
      data series.

Collaborators:

* DataSet

Instance Attribute Summary

Attributes inherited from RailsDataExplorer::Chart

#output_buffer

Instance Method Summary collapse

Methods inherited from RailsDataExplorer::Chart

#dom_id, #render?

Constructor Details

#initialize(_data_set, options = {}) ⇒ Scatterplot

Returns a new instance of Scatterplot.



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# File 'lib/rails_data_explorer/chart/scatterplot.rb', line 17

def initialize(_data_set, options = {})
  @data_set = _data_set
  @options = {}.merge(options)
end

Instance Method Details

#compute_chart_attrs ⇒ Object 



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# File 'lib/rails_data_explorer/chart/scatterplot.rb', line 22

def compute_chart_attrs
  x_candidates = @data_set.data_series.find_all { |ds|
    (ds.chart_roles[Chart::Scatterplot] & [:x, :any]).any?
  }
  y_candidates = @data_set.data_series.find_all { |ds|
    (ds.chart_roles[Chart::Scatterplot] & [:y, :any]).any?
  }
  color_candidates = @data_set.data_series.find_all { |ds|
    (ds.chart_roles[Chart::Scatterplot] & [:color, :any]).any?
  }
  size_candidates = @data_set.data_series.find_all { |ds|
    (ds.chart_roles[Chart::Scatterplot] & [:size, :any]).any?
  }

  x_ds = x_candidates.first
  y_ds = (y_candidates - [x_ds]).first
  color_ds = (color_candidates - [x_ds, y_ds]).first
  size_ds = (size_candidates - [x_ds, y_ds, color_ds]).first
  return false  if x_ds.nil? || y_ds.nil?

  ca = case @data_set.dimensions_count
  when 0,1
    raise(ArgumentError.new("At least two data series required for scatterplot, only #{ @data_set.dimensions_count } given"))
  when 2
    key = ''
    values_hash = x_ds.values.length.times.map { |idx|
      r = { x: x_ds.values[idx], y: y_ds.values[idx] }
      r[:color] = color_ds.values[idx]  if color_ds
      r
    }
    {
      values: values_hash,
      x_axis_label: x_ds.name,
      x_axis_tick_format: x_ds.axis_tick_format,
      y_axis_label: y_ds.name,
      y_axis_tick_format: y_ds.axis_tick_format,
    }
  when 3
    visual_attr_ds = color_ds || size_ds
    raise "No visual_attr_ds given"  if visual_attr_ds.nil?
    data_series_hash = visual_attr_ds.values.uniq.inject({}) { |m,visual_attr|
      m[visual_attr] = []
      m
    }
    x_ds.values.length.times.each { |idx|
      data_series_hash[visual_attr_ds.values[idx]] << { x: x_ds.values[idx], y: y_ds.values[idx] }
    }
    {
      values: data_series_hash,
      x_axis_label: x_ds.name,
      x_axis_tick_format: x_ds.axis_tick_format,
      y_axis_label: y_ds.name,
      y_axis_tick_format: y_ds.axis_tick_format,
    }
  else
  end
  ca
end

#render ⇒ Object 



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# File 'lib/rails_data_explorer/chart/scatterplot.rb', line 81

def render
  return ''  unless render?
  ca = compute_chart_attrs
  return ''  unless ca
  render_vega(ca)
end

#render_nvd3(ca) ⇒ Object 



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# File 'lib/rails_data_explorer/chart/scatterplot.rb', line 184

def render_nvd3(ca)
  %(
    <div class="rde-chart rde-scatterplot">
      <h3 class="rde-chart-title">Scatterplot</h3>
      <div id="#{ dom_id }", style="height: 400px;">
        <svg></svg>
      </div>
      <script type="text/javascript">
        (function() {
          var data = #{ ca[:values].to_json };

          nv.addGraph(function() {
            var chart = nv.models.scatterChart()
                          .showDistX(true)
                          .showDistY(true)
                          .useVoronoi(true)
                          .color(d3.scale.category10().range())
                          .transitionDuration(300)
                          ;

            chart.xAxis.tickFormat(#{ ca[:x_axis_tick_format] })
                       .axisLabel('#{ ca[:x_axis_label] }')
                       ;

            chart.yAxis.tickFormat(#{ ca[:y_axis_tick_format] })
                       .axisLabel('#{ ca[:y_axis_label] }')
                       ;

            chart.tooltipContent(function(key) {
                return key;
            });

            d3.select('##{ dom_id } svg')
                .datum(data)
                .call(chart);

            nv.utils.windowResize(chart.update);

            chart.dispatch.on('stateChange', function(e) { ('New State:', JSON.stringify(e)); });

            return chart;
          });
        })();
      </script>
    </div>
  )
end

#render_vega(ca) ⇒ Object 



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# File 'lib/rails_data_explorer/chart/scatterplot.rb', line 88

def render_vega(ca)
  %(
    <div class="rde-chart rde-scatterplot">
      <h3 class="rde-chart-title">Scatterplot</h3>
      <div id="#{ dom_id }"></div>
      <script type="text/javascript">
        (function() {
          var spec = {
            "width": 960,
            "height": 200,
            "data": [
              {
                "name": "table",
                "values": #{ ca[:values].to_json }
              },
            ],
            "scales": [
              {
                "name": "x",
                "nice": true,
                "range": "width",
                "zero": false,
                "domain": {"data": "table", "field": "data.x"}
              },
              {
                "name": "y",
                "nice": true,
                "range": "height",
                "zero": false,
                "domain": {"data": "table", "field": "data.y"}
              },
              // {
              //   "name": "c",
              //   "type": "ordinal",
              //   "domain": {"data": "iris", "field": "data.species"},
              //   "range": ["#800", "#080", "#008"]
              // }
            ],
            "axes": [
              {
                "type": "x",
                "scale": "x",
                "offset": 5,
                "title": "#{ ca[:x_axis_label] }",
              },
              {
                "type": "y",
                "scale": "y",
                "offset": 5,
                "title": "#{ ca[:y_axis_label] }",
              }
            ],
            // "legends": [
            //   {
            //     "fill": "c",
            //     "title": "Species",
            //     "offset": 0,
            //     "properties": {
            //       "symbols": {
            //         "fillOpacity": {"value": 0.5},
            //         "stroke": {"value": "transparent"}
            //       }
            //     }
            //   }
            // ],
            "marks": [
              {
                "type": "symbol",
                "from": {"data": "table"},
                "properties": {
                  "enter": {
                    "x": {"scale": "x", "field": "data.x"},
                    "y": {"scale": "y", "field": "data.y"},
                    //"fill": {"scale": "c", "field": "data.species"},
                    "fill": { "value": "#1F77B4" },
                    "fillOpacity": {"value": 0.4},
                  },
                  "update": {
                    "size": {"value": 30},
                    "stroke": {"value": "transparent"}
                  },
                }
              }
            ]
          };

          vg.parse.spec(spec, function(chart) {
            var view = chart({ el:"##{ dom_id }" }).update();
          });

        })();
      </script>
    </div>
  )
end