Vega lite grouped bar chart for time series

Question

I'm trying to create a bar grouped bar chart for time series data. There are 2 series, sampled at the same interval. The stacked bar chart looks like this:

Code: Vega lite editor code

Now, instead of stacking them, I like to create a grouped bar chart as described in the docs:

The xOffset parameter doesn't seem to like the temporal axis, though:

The bars are on top of each other instead of next to each other: Adapted code

Any tips on how to solve this?

Answer 1

You have too many data points. Adding the timeunit:month achieves this:

 "x": {
          "field": "date",
          "type": "temporal", "timeUnit": "month",
          "title": null,
          "axis": {"labelAngle": -70},
          "sort": null
        },

Or this:

   "x": {
          "field": "date",
          "type": "temporal",
          "timeUnit": "month",
          "title": null,
          "axis": {
            "tickCount": 8,
            "labelAlign": "left",
            "labelExpr": "[timeFormat(datum.value, '%b'), timeFormat(datum.value, '%m') == '01' ? timeFormat(datum.value, '%Y') : '']",
            "labelOffset": 4,
            "labelPadding": -24,
            "tickSize": 30
          },
          "sort": null
        },