{
  "$schema": "https://vega.github.io/schema/vega-lite/v2.json",
  "config": {"background":"#ffffff",
    "range": {
      "heatmap": {
        "scheme": "yellowgreenblue"
      }
    }
  },     
  "width": 600,
  "data": {"url": "data/complaints.csv", "format": {"type": "csv"}},
  "mark": "rect",
  "encoding": {
    "y": {"field": "Product", "type": "nominal"},
    "x": {
      "field": "Date received", 
      "type": "temporal", 
      "timeUnit":"yearmonth"},
    "color": {"aggregate": "count", "type": "quantitative"}
  }
}