drafted docs for new XMarkers system
drafted docs for new XMarkers system

This system will make it possible to create a ContentView with x-axis labels. Currently, the XMarker system is crude and not powerful enough. It does not even provide x-axis labels for data points which are off-screen.

unixpickle/graphalicious,unixpickle/graphalicious,unixpickle/graphalicious,unixpickle/graphalicious