Golang Plot.Transforms方法代码示例

// Plot draws the QuartPlot on Canvas c and Plot plt.
func (b *QuartPlot) Plot(c draw.Canvas, plt *plot.Plot) {
	if b.Horizontal {
		b := &horizQuartPlot{b}
		b.Plot(c, plt)
		return
	}

	trX, trY := plt.Transforms(&c)
	x := trX(b.Location)
	if !c.ContainsX(x) {
		return
	}
	x += b.Offset

	med := draw.Point{X: x, Y: trY(b.Median)}
	q1 := trY(b.Quartile1)
	q3 := trY(b.Quartile3)
	aLow := trY(b.AdjLow)
	aHigh := trY(b.AdjHigh)

	c.StrokeLine2(b.WhiskerStyle, x, aHigh, x, q3)
	if c.ContainsY(med.Y) {
		c.DrawGlyphNoClip(b.MedianStyle, med)
	}
	c.StrokeLine2(b.WhiskerStyle, x, aLow, x, q1)

	ostyle := b.MedianStyle
	ostyle.Radius = b.MedianStyle.Radius / 2
	for _, out := range b.Outside {
		y := trY(b.Value(out))
		if c.ContainsY(y) {
			c.DrawGlyphNoClip(ostyle, draw.Point{X: x, Y: y})
		}
	}
}

// Plot implements the plot.Plotter interface.
func (g *Grid) Plot(c draw.Canvas, plt *plot.Plot) {
	trX, trY := plt.Transforms(&c)

	if g.Vertical.Color == nil {
		goto horiz
	}
	for _, tk := range plt.X.Tick.Marker.Ticks(plt.X.Min, plt.X.Max) {
		if tk.IsMinor() {
			continue
		}
		x := trX(tk.Value)
		c.StrokeLine2(g.Vertical, x, c.Min.Y, x, c.Min.Y+c.Size().Y)
	}

horiz:
	if g.Horizontal.Color == nil {
		return
	}
	for _, tk := range plt.Y.Tick.Marker.Ticks(plt.Y.Min, plt.Y.Max) {
		if tk.IsMinor() {
			continue
		}
		y := trY(tk.Value)
		c.StrokeLine2(g.Horizontal, c.Min.X, y, c.Min.X+c.Size().X, y)
	}
}

// Plot implements the Plot method of the plot.Plotter interface.
func (h *Contour) Plot(c draw.Canvas, plt *plot.Plot) {
	if naive {
		h.naivePlot(c, plt)
		return
	}

	var pal []color.Color
	if h.Palette != nil {
		pal = h.Palette.Colors()
	}

	trX, trY := plt.Transforms(&c)

	// Collate contour paths and draw them.
	//
	// The alternative naive approach is to draw each line segment as
	// conrec returns it. The integrated path approach allows graphical
	// optimisations and is necessary for contour fill shading.
	cp := contourPaths(h.GridXYZ, h.Levels, trX, trY)

	// ps is a palette scaling factor to scale the palette uniformly
	// across the given levels. This enables a discordance between the
	// number of colours and the number of levels. Sorting is not
	// necessary since contourPaths sorts the levels as a side effect.
	ps := float64(len(pal)-1) / (h.Levels[len(h.Levels)-1] - h.Levels[0])
	if len(h.Levels) == 1 {
		ps = 0
	}

	for i, z := range h.Levels {
		if math.IsNaN(z) {
			continue
		}
		for _, pa := range cp[z] {
			if isLoop(pa) {
				pa.Close()
			}

			style := h.LineStyles[i%len(h.LineStyles)]
			var col color.Color
			switch {
			case z < h.Min:
				col = h.Underflow
			case z > h.Max:
				col = h.Overflow
			case len(pal) == 0:
				col = style.Color
			default:
				col = pal[int((z-h.Levels[0])*ps+0.5)] // Apply palette scaling.
			}
			if col != nil && style.Width != 0 {
				c.SetLineStyle(style)
				c.SetColor(col)
				c.Stroke(pa)
			}
		}
	}
}

// Plot implements the plot.Plotter interface.
func (b *BarChart) Plot(c draw.Canvas, plt *plot.Plot) {
	trCat, trVal := plt.Transforms(&c)
	if b.Horizontal {
		trCat, trVal = trVal, trCat
	}

	for i, ht := range b.Values {
		catVal := b.XMin + float64(i)
		catMin := trCat(float64(catVal))
		if !b.Horizontal {
			if !c.ContainsX(catMin) {
				continue
			}
		} else {
			if !c.ContainsY(catMin) {
				continue
			}
		}
		catMin = catMin - b.Width/2 + b.Offset
		catMax := catMin + b.Width
		bottom := b.stackedOn.BarHeight(i)
		valMin := trVal(bottom)
		valMax := trVal(bottom + ht)

		var pts []draw.Point
		var poly []draw.Point
		if !b.Horizontal {
			pts = []draw.Point{
				{catMin, valMin},
				{catMin, valMax},
				{catMax, valMax},
				{catMax, valMin},
			}
			poly = c.ClipPolygonY(pts)
		} else {
			pts = []draw.Point{
				{valMin, catMin},
				{valMin, catMax},
				{valMax, catMax},
				{valMax, catMin},
			}
			poly = c.ClipPolygonX(pts)
		}
		c.FillPolygon(b.Color, poly)

		var outline [][]draw.Point
		if !b.Horizontal {
			pts = append(pts, draw.Point{X: catMin, Y: valMin})
			outline = c.ClipLinesY(pts)
		} else {
			pts = append(pts, draw.Point{X: valMin, Y: catMin})
			outline = c.ClipLinesX(pts)
		}
		c.StrokeLines(b.LineStyle, outline...)
	}
}

// Plot implements the Plotter interface, drawing a line
// that connects each point in the Line.
func (f *Function) Plot(c draw.Canvas, p *plot.Plot) {
	trX, trY := p.Transforms(&c)

	d := (p.X.Max - p.X.Min) / float64(f.Samples-1)
	line := make([]draw.Point, f.Samples)
	for i := range line {
		x := p.X.Min + float64(i)*d
		line[i].X = trX(x)
		line[i].Y = trY(f.F(x))
	}
	c.StrokeLines(f.LineStyle, c.ClipLinesXY(line)...)
}

// Plot implements the Plotter interface, drawing labels.
func (e *YErrorBars) Plot(c draw.Canvas, p *plot.Plot) {
	trX, trY := p.Transforms(&c)
	for i, err := range e.YErrors {
		x := trX(e.XYs[i].X)
		ylow := trY(e.XYs[i].Y - math.Abs(err.Low))
		yhigh := trY(e.XYs[i].Y + math.Abs(err.High))

		bar := c.ClipLinesY([]draw.Point{{x, ylow}, {x, yhigh}})
		c.StrokeLines(e.LineStyle, bar...)
		e.drawCap(&c, x, ylow)
		e.drawCap(&c, x, yhigh)
	}
}

// Plot implements the Plotter interface, drawing labels.
func (l *Labels) Plot(c draw.Canvas, p *plot.Plot) {
	trX, trY := p.Transforms(&c)
	for i, label := range l.Labels {
		x := trX(l.XYs[i].X)
		y := trY(l.XYs[i].Y)
		if !c.Contains(draw.Point{X: x, Y: y}) {
			continue
		}
		x += l.XOffset
		y += l.YOffset
		c.FillText(l.TextStyle, x, y, l.XAlign, l.YAlign, label)
	}
}

// Plot draws the BoxPlot on Canvas c and Plot plt.
func (b *BoxPlot) Plot(c draw.Canvas, plt *plot.Plot) {
	if b.Horizontal {
		b := &horizBoxPlot{b}
		b.Plot(c, plt)
		return
	}

	trX, trY := plt.Transforms(&c)
	x := trX(b.Location)
	if !c.ContainsX(x) {
		return
	}
	x += b.Offset

	med := trY(b.Median)
	q1 := trY(b.Quartile1)
	q3 := trY(b.Quartile3)
	aLow := trY(b.AdjLow)
	aHigh := trY(b.AdjHigh)

	box := c.ClipLinesY([]draw.Point{
		{x - b.Width/2, q1},
		{x - b.Width/2, q3},
		{x + b.Width/2, q3},
		{x + b.Width/2, q1},
		{x - b.Width/2 - b.BoxStyle.Width/2, q1},
	})
	c.StrokeLines(b.BoxStyle, box...)

	medLine := c.ClipLinesY([]draw.Point{
		{x - b.Width/2, med},
		{x + b.Width/2, med},
	})
	c.StrokeLines(b.MedianStyle, medLine...)

	cap := b.CapWidth / 2
	whisks := c.ClipLinesY([]draw.Point{{x, q3}, {x, aHigh}},
		[]draw.Point{{x - cap, aHigh}, {x + cap, aHigh}},
		[]draw.Point{{x, q1}, {x, aLow}},
		[]draw.Point{{x - cap, aLow}, {x + cap, aLow}})
	c.StrokeLines(b.WhiskerStyle, whisks...)

	for _, out := range b.Outside {
		y := trY(b.Value(out))
		if c.ContainsY(y) {
			c.DrawGlyphNoClip(b.GlyphStyle, draw.Point{X: x, Y: y})
		}
	}
}

// Plot implements the Plotter interface, drawing a line
// that connects each point in the Line.
func (h *Histogram) Plot(c draw.Canvas, p *plot.Plot) {
	trX, trY := p.Transforms(&c)

	for _, bin := range h.Bins {
		pts := []draw.Point{
			{trX(bin.Min), trY(0)},
			{trX(bin.Max), trY(0)},
			{trX(bin.Max), trY(bin.Weight)},
			{trX(bin.Min), trY(bin.Weight)},
		}
		if h.FillColor != nil {
			c.FillPolygon(h.FillColor, c.ClipPolygonXY(pts))
		}
		pts = append(pts, draw.Point{trX(bin.Min), trY(0)})
		c.StrokeLines(h.LineStyle, c.ClipLinesXY(pts)...)
	}
}

// Plot implements the Plot method of the plot.Plotter interface.
func (bs *Bubbles) Plot(c draw.Canvas, plt *plot.Plot) {
	trX, trY := plt.Transforms(&c)

	c.SetColor(bs.Color)

	for _, d := range bs.XYZs {
		x := trX(d.X)
		y := trY(d.Y)
		if !c.Contains(draw.Point{x, y}) {
			continue
		}

		rad := bs.radius(d.Z)

		// draw a circle centered at x, y
		var p vg.Path
		p.Move(x+rad, y)
		p.Arc(x, y, rad, 0, 2*math.Pi)
		p.Close()
		c.Fill(p)
	}
}

// Plot draws the Line, implementing the plot.Plotter
// interface.
func (pts *Line) Plot(c draw.Canvas, plt *plot.Plot) {
	trX, trY := plt.Transforms(&c)
	ps := make([]draw.Point, len(pts.XYs))

	for i, p := range pts.XYs {
		ps[i].X = trX(p.X)
		ps[i].Y = trY(p.Y)
	}

	if pts.ShadeColor != nil && len(ps) > 0 {
		c.SetColor(*pts.ShadeColor)
		minY := trY(plt.Y.Min)
		var pa vg.Path
		pa.Move(ps[0].X, minY)
		for i := range pts.XYs {
			pa.Line(ps[i].X, ps[i].Y)
		}
		pa.Line(ps[len(pts.XYs)-1].X, minY)
		pa.Close()
		c.Fill(pa)
	}

	c.StrokeLines(pts.LineStyle, c.ClipLinesXY(ps)...)
}

// Plot implements the Plot method of the plot.Plotter interface.
func (h *HeatMap) Plot(c draw.Canvas, plt *plot.Plot) {
	pal := h.Palette.Colors()
	if len(pal) == 0 {
		panic("heatmap: empty palette")
	}
	// ps scales the palette uniformly across the data range.
	ps := float64(len(pal)-1) / (h.Max - h.Min)

	trX, trY := plt.Transforms(&c)

	var pa vg.Path
	cols, rows := h.GridXYZ.Dims()
	for i := 0; i < cols; i++ {

		var right, left float64
		switch i {
		case 0:
			right = (h.GridXYZ.X(i+1) - h.GridXYZ.X(i)) / 2
			left = -right
		case cols - 1:
			right = (h.GridXYZ.X(i) - h.GridXYZ.X(i-1)) / 2
			left = -right
		default:
			right = (h.GridXYZ.X(i+1) - h.GridXYZ.X(i)) / 2
			left = -(h.GridXYZ.X(i) - h.GridXYZ.X(i-1)) / 2
		}

		for j := 0; j < rows; j++ {
			v := h.GridXYZ.Z(i, j)
			if math.IsNaN(v) || math.IsInf(v, 0) {
				continue
			}

			pa = pa[:0]

			var up, down float64
			switch j {
			case 0:
				up = (h.GridXYZ.Y(j+1) - h.GridXYZ.Y(j)) / 2
				down = -up
			case rows - 1:
				up = (h.GridXYZ.Y(j) - h.GridXYZ.Y(j-1)) / 2
				down = -up
			default:
				up = (h.GridXYZ.Y(j+1) - h.GridXYZ.Y(j)) / 2
				down = -(h.GridXYZ.Y(j) - h.GridXYZ.Y(j-1)) / 2
			}

			x, y := trX(h.GridXYZ.X(i)+left), trY(h.GridXYZ.Y(j)+down)
			dx, dy := trX(h.GridXYZ.X(i)+right), trY(h.GridXYZ.Y(j)+up)

			if !c.Contains(draw.Point{x, y}) || !c.Contains(draw.Point{dx, dy}) {
				continue
			}

			pa.Move(x, y)
			pa.Line(dx, y)
			pa.Line(dx, dy)
			pa.Line(x, dy)
			pa.Close()

			var col color.Color
			switch {
			case v < h.Min:
				col = h.Underflow
			case v > h.Max:
				col = h.Overflow
			default:
				col = pal[int((v-h.Min)*ps+0.5)] // Apply palette scaling.
			}
			if col != nil {
				c.SetColor(col)
				c.Fill(pa)
			}
		}
	}
}

// naivePlot implements the a naive rendering approach for contours.
// It is here as a debugging mode since it simply draws line segments
// generated by conrec without further computation.
func (h *Contour) naivePlot(c draw.Canvas, plt *plot.Plot) {
	var pal []color.Color
	if h.Palette != nil {
		pal = h.Palette.Colors()
	}

	trX, trY := plt.Transforms(&c)

	// Sort levels prior to palette scaling since we can't depend on
	// sorting as a side effect from calling contourPaths.
	sort.Float64s(h.Levels)
	// ps is a palette scaling factor to scale the palette uniformly
	// across the given levels. This enables a discordance between the
	// number of colours and the number of levels.
	ps := float64(len(pal)-1) / (h.Levels[len(h.Levels)-1] - h.Levels[0])
	if len(h.Levels) == 1 {
		ps = 0
	}

	levelMap := make(map[float64]int)
	for i, z := range h.Levels {
		levelMap[z] = i
	}

	// Draw each line segment as conrec generates it.
	var pa vg.Path
	conrec(h.GridXYZ, h.Levels, func(_, _ int, l line, z float64) {
		if math.IsNaN(z) {
			return
		}

		pa = pa[:0]

		x1, y1 := trX(l.p1.X), trY(l.p1.Y)
		x2, y2 := trX(l.p2.X), trY(l.p2.Y)

		if !c.Contains(draw.Point{x1, y1}) || !c.Contains(draw.Point{x2, y2}) {
			return
		}

		pa.Move(x1, y1)
		pa.Line(x2, y2)
		pa.Close()

		style := h.LineStyles[levelMap[z]%len(h.LineStyles)]
		var col color.Color
		switch {
		case z < h.Min:
			col = h.Underflow
		case z > h.Max:
			col = h.Overflow
		case len(pal) == 0:
			col = style.Color
		default:
			col = pal[int((z-h.Levels[0])*ps+0.5)] // Apply palette scaling.
		}
		if col != nil && style.Width != 0 {
			c.SetLineStyle(style)
			c.SetColor(col)
			c.Stroke(pa)
		}
	})
}

// Plot draws the Scatter, implementing the plot.Plotter
// interface.
func (pts *Scatter) Plot(c draw.Canvas, plt *plot.Plot) {
	trX, trY := plt.Transforms(&c)
	for _, p := range pts.XYs {
		c.DrawGlyph(pts.GlyphStyle, draw.Point{trX(p.X), trY(p.Y)})
	}
}