ZacharyZhang-NY
596c62e026
Bars, lines, areas, pies, donuts, radar, histogram, scatter, bubbles, heatmaps, gauge, bullet, funnel, waterfall, treemap, candles, box plots, steps, rings, legend, axis, crosshair, polar area, pyramid, spectrum bars and win-loss strips, each drawn dot by dot. Ticks follow 1-2-5 steps and print as precisely as their step needs; a label row uses micro letters or the pixel font as a whole. Descriptions carry the data in numbers. Bad data panics.
63 lines
1.4 KiB
Go
63 lines
1.4 KiB
Go
package chart
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import (
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"fmt"
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"math"
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"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
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)
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// turn is a dot's angle, 0–1 clockwise from twelve.
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func turn(dx, dy int) float64 {
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a := math.Atan2(float64(dx)+0.5, -float64(dy)-0.5) / (2 * math.Pi)
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if a < 0 {
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a++
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}
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return a
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}
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// sector fills dots between radii r0–r1 and turns a0–a1.
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func sector(g pixel.Canvas, cx, cy, r0, r1 int, a0, a1 float64, s pixel.Slot) {
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for dy := -r1; dy <= r1; dy++ {
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for dx := -r1; dx <= r1; dx++ {
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d := dx*dx + dy*dy
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if d > r1*r1+r1 || d < r0*r0 {
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continue
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}
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if a := turn(dx, dy); a >= a0 && a < a1 {
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g.Dot(cx+dx, cy+dy, s)
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}
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}
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}
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}
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// shares are slices' fractions of their total, checked.
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func shares(slices []Slice) (total float64, cuts []float64) {
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for _, s := range slices {
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if s.Value < 0 || math.IsNaN(s.Value) || math.IsInf(s.Value, 0) {
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panic(fmt.Sprintf("chart: slice %q has value %v", s.Name, s.Value))
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}
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total += s.Value
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}
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if total == 0 {
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panic("chart: slices sum to zero")
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}
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at := 0.0
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cuts = []float64{0}
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for _, s := range slices {
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at += s.Value / total
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cuts = append(cuts, at)
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}
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cuts[len(cuts)-1] = 1
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return total, cuts
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}
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// readSlices lists slices for assistive technology.
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func readSlices(slices []Slice) string {
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labels, values := make([]string, len(slices)), make([]float64, len(slices))
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for i, s := range slices {
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labels[i], values[i] = s.Name, s.Value
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}
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return read(labels, values)
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}
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