Using go-chart to generate a graph based on the PRO Prisundersökning data converted using https://gist.github.com/peterhellberg/ceed862a83c29a80b5bbd4631c24fb27

pro-prisundersokning-graph.go

package main

import (
	"encoding/json"
	"fmt"
	"os"
	"strings"

	_ "embed"

	"github.com/wcharczuk/go-chart/v2"
	"github.com/wcharczuk/go-chart/v2/drawing"
)

var (
	orange = drawing.ColorFromHex("FF6600")
	blue   = drawing.ColorFromHex("0099FF")
	gray   = drawing.ColorFromHex("363636")
)

func main() {
	var butiker []butik

	if err := json.Unmarshal(data, &butiker); err != nil {
		panic(err)
	}

	totals := make([]float64, len(butiker))

	var combinedTotal float64

	for i, butik := range butiker {
		totals[i] = butik.Total
		combinedTotal += butik.Total
	}

	averageTotal := combinedTotal / float64(len(totals))

	zero := chart.GridLine{
		Value: averageTotal,
		Style: chart.Style{
			StrokeWidth:     15,
			StrokeColor:     orange.WithAlpha(30),
			StrokeDashArray: []float64{20, 20},
		},
	}

	S, N := 0, 36

	for n := S; n < N; n++ {
		var varorNamn string

		priser := make([]float64, len(butiker))

		for i, butik := range butiker {
			priser[i] = butik.Varor[n].Pris
			varorNamn = butik.Varor[n].Namn
		}

		mainSeries := chart.ContinuousSeries{
			YAxis: chart.YAxisSecondary,
			Style: chart.Style{
				StrokeColor: orange.WithAlpha(80),
				StrokeWidth: 32,
				DotColor:    orange,
				DotWidth:    6,
			},
			XValues: chart.LinearRange(1, float64(len(totals))),
			YValues: chart.ValueSequence(totals...).Values(),
		}

		priserSeries := chart.ContinuousSeries{
			Style: chart.Style{
				StrokeColor: blue.WithAlpha(100),
				StrokeWidth: 3,
				DotColor:    blue.WithAlpha(130),
				DotWidth:    9,
			},
			XValues: chart.LinearRange(1, float64(len(totals))),
			YValues: chart.ValueSequence(priser...).Values(),
		}

		graph := chart.Chart{
			Title: "Hela matkassens pris jämfört med " + varorNamn,
			TitleStyle: chart.Style{
				FontSize:  20,
				FontColor: gray,
			},
			DPI:    216,
			Width:  3072,
			Height: 1536,
			XAxis: chart.XAxis{
				Style: chart.Style{
					Hidden: true,
				},
			},
			YAxisSecondary: chart.YAxis{
				Zero: zero,
				Name: "Hela matkassen",
				NameStyle: chart.Style{
					FontSize:  -16,
					FontColor: orange,
				},
				Style: chart.Style{
					FontSize:    14,
					StrokeWidth: 4,
					StrokeColor: orange,
					FontColor:   orange,
				},
				ValueFormatter: krFormatter,
			},
			YAxis: chart.YAxis{
				Name: varorNamn,
				NameStyle: chart.Style{
					FontSize:  16,
					FontColor: blue,
				},
				Style: chart.Style{
					FontSize:    14,
					StrokeWidth: 4,
					StrokeColor: blue,
					FontColor:   blue,
				},
				ValueFormatter: krFormatter,
			},
			Background: chart.Style{
				Padding: chart.NewBox(80, 60, 20, 20),
			},
			Series: []chart.Series{
				priserSeries,
				mainSeries,
			},
		}

		fn := strings.ToLower(
			fmt.Sprintf("pro-prisundersokning-total-vs-%s.png",
				strings.ReplaceAll(varorNamn, " ", "-"),
			),
		)

		f, err := os.Create(fn)
		if err != nil {
			panic(err)
		}
		defer f.Close()

		if err := graph.Render(chart.PNG, f); err != nil {
			panic(err)
		}
	}
}

func krFormatter(v interface{}) string {
	return chart.FloatValueFormatterWithFormat(v, " %.0f kr")
}

//go:embed data.json
var data []byte

type butik struct {
	Butiksnamn string  `json:"butiksnamn"`
	Distrikt   string  `json:"distrikt"`
	Typ        string  `json:"typ"`
	AntalVaror int     `json:"antal_varor"`
	Total      float64 `json:"total"`
	Varor      []vara  `json:"varor"`
}

type vara struct {
	Namn string  `json:"namn"`
	Pris float64 `json:"pris"`
}