plot/plotter/functions.go at master · ffhelicopter/plot · GitHub

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// Use of this source code is governed by a BSD-style

// license that can be found in the LICENSE file.

package plotter

import (

"gonum.org/v1/plot"

"gonum.org/v1/plot/vg"

"gonum.org/v1/plot/vg/draw"

)

// Function implements the Plotter interface,

// drawing a line for the given function.

type Function struct {

F func(x float64) (y float64)

// XMin and XMax specify the range

// of x values to pass to F.

XMin, XMax float64

Samples int

draw.LineStyle

}

// NewFunction returns a Function that plots F using

// the default line style with 50 samples.

func NewFunction(f func(float64) float64) *Function {

return &Function{

F: f,

Samples: 50,

LineStyle: DefaultLineStyle,

}

// 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)

min, max := f.XMin, f.XMax

if min == 0 && max == 0 {

min = p.X.Min

max = p.X.Max

}

d := (max - min) / float64(f.Samples-1)

line := make([]vg.Point, f.Samples)

for i := range line {

x := min + float64(i)*d

line[i].X = trX(x)

line[i].Y = trY(f.F(x))

}

c.StrokeLines(f.LineStyle, c.ClipLinesXY(line)...)

}

// Thumbnail draws a line in the given style down the

// center of a DrawArea as a thumbnail representation

// of the LineStyle of the function.

func (f Function) Thumbnail(c *draw.Canvas) {

y := c.Center().Y

c.StrokeLine2(f.LineStyle, c.Min.X, y, c.Max.X, y)

}

plot/plotter/functions.go at master · ffhelicopter/plot · GitHub

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