fixed dependencies

vendor/gonum.org/v1/plot/plotter/grid.go

@@ -0,0 +1,81 @@
+// Copyright ©2015 The Gonum Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package plotter
+
+import (
+	"image/color"
+
+	"gonum.org/v1/plot"
+	"gonum.org/v1/plot/vg"
+	"gonum.org/v1/plot/vg/draw"
+)
+
+var (
+	// DefaultGridLineStyle is the default style for grid lines.
+	DefaultGridLineStyle = draw.LineStyle{
+		Color: color.Gray{128},
+		Width: vg.Points(0.25),
+	}
+)
+
+// Grid implements the plot.Plotter interface, drawing
+// a set of grid lines at the major tick marks.
+type Grid struct {
+	// Vertical is the style of the vertical lines.
+	Vertical draw.LineStyle
+
+	// Horizontal is the style of the horizontal lines.
+	Horizontal draw.LineStyle
+}
+
+// NewGrid returns a new grid with both vertical and
+// horizontal lines using the default grid line style.
+func NewGrid() *Grid {
+	return &Grid{
+		Vertical:   DefaultGridLineStyle,
+		Horizontal: DefaultGridLineStyle,
+	}
+}
+
+// Plot implements the plot.Plotter interface.
+func (g *Grid) Plot(c draw.Canvas, plt *plot.Plot) {
+	trX, trY := plt.Transforms(&c)
+
+	var (
+		ymin = c.Min.Y
+		ymax = c.Max.Y
+		xmin = c.Min.X
+		xmax = c.Max.X
+	)
+
+	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)
+		if x > xmax || x < xmin {
+			continue
+		}
+		c.StrokeLine2(g.Vertical, x, ymin, x, ymax)
+	}
+
+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)
+		if y > ymax || y < ymin {
+			continue
+		}
+		c.StrokeLine2(g.Horizontal, xmin, y, xmax, y)
+	}
+}