mopac-pdf v0: markdown to beautiful PDFs via digest-pinned typst

Go CLI that turns the markdown currency of this stack (Redmine notes,
Discourse posts, briefing output) into typeset PDFs: two embedded typst
templates (report with title page/TOC/headers, dense brief), front-matter
(title/subtitle/author/date/classification/template), GFM tables, and
bar charts rendered in pure Go (go-chart) from fenced chart data blocks.
Engine is a prebuilt typst 0.15.1 container pinned by digest and run
--network none; PDF bytes to stdout or -o. Exit codes 0/1/2.

All dev in docker (dev.sh/Makefile); unit tests + golden typst fixtures
plus a host-side smoke against the real engine container.

Generated with Crush

Assisted-by: Crush:glm-5.2

vendor/github.com/wcharczuk/go-chart/v2/ema_series.go

@@ -0,0 +1,131 @@
+package chart
+
+import "fmt"
+
+const (
+	// DefaultEMAPeriod is the default EMA period used in the sigma calculation.
+	DefaultEMAPeriod = 12
+)
+
+// Interface Assertions.
+var (
+	_ Series              = (*EMASeries)(nil)
+	_ FirstValuesProvider = (*EMASeries)(nil)
+	_ LastValuesProvider  = (*EMASeries)(nil)
+)
+
+// EMASeries is a computed series.
+type EMASeries struct {
+	Name  string
+	Style Style
+	YAxis YAxisType
+
+	Period      int
+	InnerSeries ValuesProvider
+
+	cache []float64
+}
+
+// GetName returns the name of the time series.
+func (ema EMASeries) GetName() string {
+	return ema.Name
+}
+
+// GetStyle returns the line style.
+func (ema EMASeries) GetStyle() Style {
+	return ema.Style
+}
+
+// GetYAxis returns which YAxis the series draws on.
+func (ema EMASeries) GetYAxis() YAxisType {
+	return ema.YAxis
+}
+
+// GetPeriod returns the window size.
+func (ema EMASeries) GetPeriod() int {
+	if ema.Period == 0 {
+		return DefaultEMAPeriod
+	}
+	return ema.Period
+}
+
+// Len returns the number of elements in the series.
+func (ema EMASeries) Len() int {
+	return ema.InnerSeries.Len()
+}
+
+// GetSigma returns the smoothing factor for the serise.
+func (ema EMASeries) GetSigma() float64 {
+	return 2.0 / (float64(ema.GetPeriod()) + 1)
+}
+
+// GetValues gets a value at a given index.
+func (ema *EMASeries) GetValues(index int) (x, y float64) {
+	if ema.InnerSeries == nil {
+		return
+	}
+	if len(ema.cache) == 0 {
+		ema.ensureCachedValues()
+	}
+	vx, _ := ema.InnerSeries.GetValues(index)
+	x = vx
+	y = ema.cache[index]
+	return
+}
+
+// GetFirstValues computes the first moving average value.
+func (ema *EMASeries) GetFirstValues() (x, y float64) {
+	if ema.InnerSeries == nil {
+		return
+	}
+	if len(ema.cache) == 0 {
+		ema.ensureCachedValues()
+	}
+	x, _ = ema.InnerSeries.GetValues(0)
+	y = ema.cache[0]
+	return
+}
+
+// GetLastValues computes the last moving average value but walking back window size samples,
+// and recomputing the last moving average chunk.
+func (ema *EMASeries) GetLastValues() (x, y float64) {
+	if ema.InnerSeries == nil {
+		return
+	}
+	if len(ema.cache) == 0 {
+		ema.ensureCachedValues()
+	}
+	lastIndex := ema.InnerSeries.Len() - 1
+	x, _ = ema.InnerSeries.GetValues(lastIndex)
+	y = ema.cache[lastIndex]
+	return
+}
+
+func (ema *EMASeries) ensureCachedValues() {
+	seriesLength := ema.InnerSeries.Len()
+	ema.cache = make([]float64, seriesLength)
+	sigma := ema.GetSigma()
+	for x := 0; x < seriesLength; x++ {
+		_, y := ema.InnerSeries.GetValues(x)
+		if x == 0 {
+			ema.cache[x] = y
+			continue
+		}
+		previousEMA := ema.cache[x-1]
+		ema.cache[x] = ((y - previousEMA) * sigma) + previousEMA
+	}
+}
+
+// Render renders the series.
+func (ema *EMASeries) Render(r Renderer, canvasBox Box, xrange, yrange Range, defaults Style) {
+	style := ema.Style.InheritFrom(defaults)
+	Draw.LineSeries(r, canvasBox, xrange, yrange, style, ema)
+}
+
+// Validate validates the series.
+func (ema *EMASeries) Validate() error {
+	if ema.InnerSeries == nil {
+		return fmt.Errorf("ema series requires InnerSeries to be set")
+	}
+	return nil
+}