function plotData() {
  logStatus('Rendering data plot...');
  const {timeSpan, series1, series2, normalize, scatter} = getDataVizOptions();

  if (scatter && series1 !== 'None' && series2 !== 'None') {
    // Plot the two series against each other.
    makeTimeSeriesScatterPlot(series1, series2, timeSpan, normalize);
  } else {
    // Plot one or two series agains time.
    makeTimeSeriesChart(
        series1, series2, timeSpan, normalize, dataChartContainer);
  }

  updateDateTimeRangeSpan(jenaWeatherData);
  updateScatterCheckbox();
  logStatus('Done rendering chart.');
}
Render data chart.

The rendered visualization obeys:

- The dropdown menus for the timeseries.
- The "Plot against each other" checkbox.
- The "Normalize data" checkbox.

Depending on the status of the UI contorls, the chart may be

- A line chart that plots one or two timeseries against time, or
- A scatter plot that plots two timeseries against on another.