Allow stacking data sets in Line Chart

[KarthikRIyer]

A stack plot is similar to a Line Plot, the difference being that the data sets are stacked over one another. A simple example can be found here.

This task will require you to implement the following:

• Add functions to atleast two from the three renderers (AGG/SVG/CoreGraphics) to allow drawing of solid polygons.
• Add the capability to allow stacking of data sets in Line Chart.

[boronhub]

Hi, I'm interested in working on this.

[KarthikRIyer]

@boronhub that's great! You should claim the task on the GCI website and also state there that you're interested in working on this issue. If you have any other questions, feel free to ask.

[boronhub]

One of my other tasks still hasn't been reviewed, so I can't claim it yet. Can I still start work on this so as to familiarize myself with SwiftPlot ?

[KarthikRIyer]

@boronhub sure!

[boronhub]

Is there a Google Group or an IRC where we can discuss this ?

[KarthikRIyer]

There is a Google Group for Swift for TensorFlow, but I prefer we discuss it here in GitHub issues.

[boronhub]

The changes have to be made in LineChart.swift, right ?

[KarthikRIyer]

@boronhub yes. You need to make changes in LineChart.swift.
You can create a file LineChartSeriesOptions.swift similar to HistogramSeriesOptions.swift. Using that you can decide if you want the plot to be stacked or not.

[KarthikRIyer]

@karwa do you have any suggestions regarding this?

[karwa]

Not particularly - just to follow the example set by BarGraph when it comes to stacking.

Matplotlib calls this a stackplot and has this as a separate kind of chart. I think that would probably also make sense for us, rather than combining it with the line chart (for example, you can't have multiple series on a line chart if the some of the series also have stacks and are filled underneath).

[KarthikRIyer]

I agree. @boronhub you could make a new chart type. I think you should be able to lift most of the code from line chart and make the required changes to get it working.

[boronhub]

The example notebook isn't working in Jupyter.
It's saying Line magic command '%install' not found.

[KarthikRIyer]

@boronhub the example notebook isn't updated. Are you using swift-jupyter, or colab?

[boronhub]

colab