F＃图表示例

Question

我想使用内置功能或免费库在F＃中做一些基本的图表。 如果可能的话，我会非常满意它的一个非常基本的例子，一个饼图。

示例数据：

[("John",34);("Sara",30);("Will",20);("Maria",16)] 

其中int是要在馅饼中表示的百分比。

我最近安装了VSLab，虽然我发现了很多3D示例，但我只是在寻找一个简单的饼图......

顺便使用excel功能也很好，不是免费的，但是安装了..

Answer 1

这是我使用Google Chart API一起粉碎的东西，我希望代码足够清晰，不需要进一步解释：

//Built with F# 1.9.7.8
open System.IO
open System.Net
open Microsoft.FSharp.Control.WebExtensions
//Add references for the namespaces below if you're not running this code in F# interactive
open System.Drawing 
open System.Windows.Forms 

let buildGoogleChartUri input =
    let chartWidth, chartHeight = 250,100

    let labels,data = List.unzip input
    let dataString = 
        data 
        |> List.map (box>>string) //in this way, data can be anything for which ToString() turns it into a number
        |> List.toArray |> String.concat ","

    let labelString = labels |> List.toArray |> String.concat "|"

    sprintf "http://chart.apis.google.com/chart?chs=%dx%d&chd=t:%s&cht=p3&chl=%s"
            chartWidth chartHeight dataString labelString

//Bake a bitmap from the google chart URI
let buildGoogleChart myData =
    async {
        let req = HttpWebRequest.Create(buildGoogleChartUri myData)
        let! response = req.AsyncGetResponse()
        return new Bitmap(response.GetResponseStream())
    } |> Async.RunSynchronously

//invokes the google chart api to build a chart from the data, and presents the image in a form
//Excuse the sloppy winforms code
let test() =
    let myData = [("John",34);("Sara",30);("Will",20);("Maria",16)]

    let image = buildGoogleChart myData
    let frm = new Form()
    frm.BackgroundImage <- image
    frm.BackgroundImageLayout <- ImageLayout.Center
    frm.ClientSize <- image.Size
    frm.Show()

Answer 2

做“在家制作”饼图很容易：打开System.Drawing

let red = new SolidBrush(Color.Red) in
let green = new SolidBrush(Color.Green) in
let blue = new SolidBrush(Color.Blue) in
let rec colors =
  seq {
    yield red
    yield green
    yield blue
    yield! colors
  }


let pie data (g: Graphics) (r: Rectangle) =
  let vals = 0.0 :: List.map snd data
  let total = List.sum vals
  let angles = List.map (fun v -> v/total*360.0) vals
  let p = new Pen(Color.Black,1)
  Seq.pairwise vals |> Seq.zip colors |> Seq.iter (fun (c,(a1,a2)) -> g.DrawPie(p,r,a1,a2); g.FillPie(c,r,a1,a2))

Answer 3

老问题，但技术在变化。

在vs 2013，F＃3和安装nuget包

 Install-Package FSharp.Charting

添加参考：

    System.Windows.Forms
    System.Windows.Forms.DataVisualization

并使用一行代码：

     Application.Run ((Chart.Pie data).ShowChart())

以下F＃代码生成bie图表：

open System
open System.Windows.Forms
open FSharp.Charting

[<EntryPoint>]
let main argv =  
    Application.EnableVisualStyles()
    Application.SetCompatibleTextRenderingDefault false   
    let data =[("John",34);("Sara",30);("Will",20);("Maria",16)]      
    Application.Run ((Chart.Pie data).ShowChart())
    0

你得到以下图表：

Answer 4

最初我只是试图通过一个非常简单的窗口对话框来显示一个馅饼来补充ssp的例子。 但是尝试这个我在ssp的代码中发现了一个错误：一方面Seq.pairwise对vals而不是angles进行操作，另一方面它显然不会考虑从开始角度沿扫描角度开始绘制饼图。

我纠正错误，评论说，重新排列，重新格式化并重新命名为一些事情-并使其既#load在fsi.exe -able和编译与fsc.exe：

#light
module YourNamespace.PieExample

open System
open System.Drawing
open System.ComponentModel
open System.Windows.Forms

(* (circular) sequence of three colors *)
#nowarn "40"
let red = new SolidBrush(Color.Red)
let green = new SolidBrush(Color.Green)
let blue = new SolidBrush(Color.Blue)
let rec colors =
    seq { yield red
          yield green
          yield blue
          yield! colors }

(* core function to build up and show a pie diagram *)
let pie data (g: Graphics) (r: Rectangle) =
    // a pen for borders of pie slices
    let p = new Pen(Color.Black, 1.0f)
    // retrieve pie shares from data and sum 'em up
    let vals  = List.map snd data
    let total = List.sum vals
    // baking a pie starts here with ...
    vals
    // scaling vals in total to a full circle
    |> List.map (fun v -> v * 360.0 / total)
    // transform list of angles to list of pie slice delimiting angles
    |> List.scan (+) 0.0
    // turn them into a list of tuples consisting of start and end angles
    |> Seq.pairwise
    // intermix the colors successively
    |> Seq.zip colors 
    // and at last do FillPies and DrawPies with these ingredients
    |> Seq.iter (fun (c,(starta,enda))
                     -> g.FillPie(c,r,(float32 starta)
                                     ,(float32 (enda - starta)))
                        g.DrawPie(p,r,(float32 starta)
                                     ,(float32 (enda - starta))))

(* demo data *)
let demolist = [ ("a", 1.); ("b", 2.); ("c", 3.);
                 ("d", 2.); ("e", 2.); ("f", 2.) ]

(* finally a simple resizable form showing demo data as pie with 6 slices *)
let mainform = new Form(MinimumSize = Size(200,200))
// add two event handlers
mainform.Paint.Add (fun e -> pie demolist e.Graphics mainform.ClientRectangle)
mainform.Resize.Add (fun _ -> mainform.Invalidate())
#if COMPILED
Application.Run(mainform)
#else
mainform.ShowDialog() |> ignore
#endif

最后但并非最不重要的是，我想提一下我认为有用的两个有用的提示

• 在一个stackoverflow.com回答ildjarn ，他在那里展示了令人惊叹的（至少对我而言） List.scan用法
• 在Shalini Juneja的c-sharpcorner.com博客中 ，她展示了如何使用F＃创建和绘制一个简单的可调整大小的窗体对话框（实际上她还展示了如何显示饼图）