[Feature] Line charts with uppper and lower boundaries

I’m submitting a … (check one with “x”)

[ ] bug report => search github for a similar issue or PR before submitting
[x] feature request
[ ] support request => Please do not submit support request here

Current behavior I’d like to contribute a pull request adding optional upper and lower boundaries to line charts.

Expected behavior Consider this chart showing the fuel consumption of my cars when driving at different speeds. The average fuel consumption doesn’t tell the whole story. It’s interesting to add the minimal and maximal fuel consumption because this shows the influence of traffic conditions. This type of use case is fairly common.

I’ve implemented a proof of concept: https://github.com/stephanrauh/ExploringAngular/tree/master/charts/complexCharts/src/app/line-range-chart However, when submitting the pull request, I’d prefer to add this as an option extending the current line charts (as opposed to adding a new chart type).

Reproduction of the problem It’s a new feature.

What is the motivation / use case for changing the behavior? Optionally adding additional information to the line charts.

Please tell us about your environment: Not relevant - it’s a new feature.

• ngx-charts version: x.x.x 3.0.3

• Angular version: 2.x.x Not relevant - it’s a new feature.

• Browser: [all] Not relevant - it’s a new feature.

• Language: [all] Not relevant - it’s a new feature.

[marjan-georgiev]

This is a great feature!

Your implementation also looks spot on. Please go ahead with the pull request.

We should also modify the tooltip (the one on individual circles) to show these min and max values.

[stephanrauh]

Now it looks even better 😃. I’m a bit unhappy with my implementation of the circle tooltips. I had to pass the min and max as separate parameters, which doesn’t match the style of the rest of the implementation. Maybe you need to have a look at this (circle-series-components.ts, getTooltipText(), line 144 and line 137/138).