Example #1
0
func plotSparks(xys plotter.XYs) (image.Image, error) {

	border := 4
	if optRows == 1 {
		border = 1
	} else if optRows == 2 {
		border = 2
	}
	height := optCharHeight * optRows
	width := (optCharWidth * 2) + (optCharWidth * len(xys))
	img := image.NewRGBA(image.Rect(0, 0, width, height))

	_, _, ymin, ymax := plotter.XYRange(xys)
	ymin = 0

	for i, xy := range xys {

		//xf := (xy.X - xmin) / xmax
		yf := (xy.Y - ymin) / ymax
		hm := height - int(float64(height-(border*2))*yf) - border
		h0 := height - border

		w := ((i + 1) * optCharWidth)
		for h := h0; h >= hm; h = h - 2 {
			var c color.RGBA
			if h == hm || h == hm+1 {
				c = color.RGBA{0, 255, 0, 255}
			} else if h == h0 {
				c = color.RGBA{0, 128, 0, 255}
			} else {
				p := float64(h-hm)/float64(h0-hm)*0.5 + 0.3
				g := uint8(float64(255) - (p * float64(255)))
				c = color.RGBA{0, g, 0, 255}
			}
			for j := 0; j < (optCharWidth - 2); j++ {
				img.SetRGBA(w+j, h, c)
			}
		}
	}

	return img, nil
}
Example #2
0
func (cg *ColorGrid) DataRange() (xmin, xmax, ymin, ymax float64) {
	// we use the XYRange function from the plotter package
	// to compute the minimum and maximum X and Y values.
	return plotter.XYRange(plotter.XYValues{cg.XYZs})
}
Example #3
0
func (s *SparkLines) DataRange() (xmin, xmax, ymin, ymax float64) {
	return plotter.XYRange(s.XYs)
}