Current history card does some autoscaling magic which isn’t ideal for all cases. Some entities (i.e. battery level) make more sense in a chart that includes zero in the scale, since my primary motivator for looking at them is to see the overall state of charge and macro changes in charge level. The current implementation would show a minor 1% dip as a massive drop if the battery level had otherwise been holding steady.
Some other customizations would also improve chart usefulness:
- Points vs lines vs lines + points vs bars.
- Much finer granularity for hours_to_show - sometimes, I want to show the last 60 seconds, especially for fast-updating entities.
- Ability to choose line color. Especially useful if you have two charts comparing derivative entities, having matching colors helps.
- Threshold lines, i.e. horizontal lines at a fixed Y value.
- Highlight and bring-to-top the associated line in the chart when I hover over the entity in the legend.
- Be able to scroll + zoom in and out with the mousewheel/click-and-drag/pinch.
- Be able to ignore “unknown” values and just connect the dots between valid points. Otherwise the line just breaks up.
