This is a brief overview of charts.
Charts app: HealthChartsAppController
Charts view: SynchronizedHealthCharts
To customize charts, implement a IChartModifier and a IChartModifierFactory. Register an instance of your IChartModifierFactory in your plugin module. See the ASDoc comments on these interfaces for some documentation.
If you need a chart for data other than MedicationAdministration or VitalSign (such as for HealthActionResult or Wellness) implement a IChartDescriptor and create an instance in your IChartModifier.updateChartDescriptors() method.
To customize the data series used or the appearance of data in the Cartesian chart, you can do so in the IChartModifier.createMainChartSeriesDataSets() method.