Self-contained, plain Go implementation of calendar heatmap inspired by Github contribution activity.

Basic

Colorscales

Without month separator

Without labels

Without labels, without separator

Example module:

countByDayOfYear := map[int]int{
    1: 10,
    22: 15,
    150: 22,
    366: 55,
}

img := charts.NewHeatmap(charts.HeatmapConfig{
    Year:               2020,
    CountByDay:         countByDay,
    ColorScale:         colorscales.PuBu9,
    DrawMonthSeparator: true,
    DrawLabels:         true,
    ...
})

Example script:

go run main.go -h