Files
gonum/graph/layout/plotter_test.go
Dan Kortschak 142f1a8c6b graph: make graph analysis routines safe for indeterminate iterators
This is a change in design for the graph.NodesOf family of functions. The
alternative was to provide an equivalent set of non-panicking routines in
graph for internal use. The protection that was intended with the panic
was to panic early rather than late when an indeterminate iterator exhausts
slice index space. I think in hindsight this was an error and we should
let things blow up in that (likely rare) situation.

The majority of changes are in test code. Outside the iterator package, which
is intimately tied to the determined iterator implementations, only one test
now fails if an indeterminate iterator is used, product's Modular extended
sub-graph isomorphism example, which is an algorithm that would have time
complexity issues with large iterators anyway.
2020-07-02 07:47:46 +09:30

146 lines
3.1 KiB
Go

// Copyright ©2019 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 layout
import (
"fmt"
"image/color"
"math"
"gonum.org/v1/plot"
"gonum.org/v1/plot/plotter"
"gonum.org/v1/plot/vg"
"gonum.org/v1/plot/vg/draw"
)
const radius = vg.Length(15)
// render implements the plot.Plotter interface for graphs.
type render struct {
GraphR2
}
func (p render) Plot(c draw.Canvas, plt *plot.Plot) {
nodes := p.GraphR2.Nodes()
if nodes.Len() == 0 {
return
}
var (
xys plotter.XYs
ids []string
)
if nodes.Len() >= 0 {
xys = make(plotter.XYs, 0, nodes.Len())
ids = make([]string, 0, nodes.Len())
}
for nodes.Next() {
u := nodes.Node()
uid := u.ID()
ur2 := p.GraphR2.LayoutNodeR2(uid)
xys = append(xys, plotter.XY(ur2.Coord2))
ids = append(ids, fmt.Sprint(uid))
to := p.GraphR2.From(uid)
for to.Next() {
v := to.Node()
vid := v.ID()
vr2 := p.GraphR2.LayoutNodeR2(vid)
l, err := plotter.NewLine(plotter.XYs{plotter.XY(ur2.Coord2), plotter.XY(vr2.Coord2)})
if err != nil {
panic(err)
}
l.Plot(c, plt)
if err != nil {
panic(err)
}
}
}
n, err := plotter.NewScatter(xys)
if err != nil {
panic(err)
}
n.GlyphStyle.Shape = nodeGlyph{}
n.GlyphStyle.Radius = radius
n.Plot(c, plt)
l, err := plotter.NewLabels(plotter.XYLabels{XYs: xys, Labels: ids})
if err != nil {
panic(err)
}
fnt, err := vg.MakeFont(plot.DefaultFont, vg.Points(18))
if err != nil {
panic(err)
}
for i := range l.TextStyle {
l.TextStyle[i] = draw.TextStyle{Font: fnt, XAlign: draw.XCenter, YAlign: -0.33}
}
l.Plot(c, plt)
}
// DataRange returns the minimum and maximum X and Y values
func (p render) DataRange() (xmin, xmax, ymin, ymax float64) {
nodes := p.GraphR2.Nodes()
if nodes.Len() == 0 {
return
}
var xys plotter.XYs
if nodes.Len() >= 0 {
xys = make(plotter.XYs, 0, nodes.Len())
}
for nodes.Next() {
u := nodes.Node()
uid := u.ID()
ur2 := p.GraphR2.LayoutNodeR2(uid)
xys = append(xys, plotter.XY(ur2.Coord2))
}
return plotter.XYRange(xys)
}
// GlyphBoxes returns a slice of plot.GlyphBoxes, implementing the
// plot.GlyphBoxer interface.
func (p render) GlyphBoxes(plt *plot.Plot) []plot.GlyphBox {
nodes := p.GraphR2.Nodes()
if nodes.Len() == 0 {
return nil
}
var b []plot.GlyphBox
if nodes.Len() >= 0 {
b = make([]plot.GlyphBox, 0, nodes.Len())
}
for i := 0; nodes.Next(); i++ {
u := nodes.Node()
uid := u.ID()
ur2 := p.GraphR2.LayoutNodeR2(uid)
b = append(b, plot.GlyphBox{})
b[i].X = plt.X.Norm(ur2.Coord2.X)
b[i].Y = plt.Y.Norm(ur2.Coord2.Y)
r := radius
b[i].Rectangle = vg.Rectangle{
Min: vg.Point{X: -r, Y: -r},
Max: vg.Point{X: +r, Y: +r},
}
}
return b
}
// nodeGlyph is a glyph that draws a filled circle.
type nodeGlyph struct{}
// DrawGlyph implements the GlyphDrawer interface.
func (nodeGlyph) DrawGlyph(c *draw.Canvas, sty draw.GlyphStyle, pt vg.Point) {
var p vg.Path
c.Push()
c.SetColor(color.White)
p.Move(vg.Point{X: pt.X + sty.Radius, Y: pt.Y})
p.Arc(pt, sty.Radius, 0, 2*math.Pi)
p.Close()
c.Fill(p)
c.Pop()
c.Stroke(p)
}