【TeeChart .NET教程】（七）使用函数

【下载TeeChart.Net最新版本】

（一）功能类型

1.1 功能类型

TeeChart Pro功能是一个系列，几乎可以是任何系列类型，应用代数功能，数据源是另一个图表系列。所有函数都派生自Steema.TeeChart.Functions命名空间中的Function类，并继承Function的 Period属性。TeeChart Pro提供以下预定义功能列表：

多种功能类型仅支持一个输入系列。但是，可以链接链接函数，例如，将图表中多个系列的平均值创建为平均函数系列，然后使用平均函数作为趋势函数的输入来标识平均值的趋势。

添加功能

从一个完全空的Chart开始，这里是代码中用于构建简单的Series-Function相关Chart的步骤。

[C#.Net]

private void Form1_Load(object sender, System.EventArgs e)            //Add a data Series            Line line1 = new Line(tChart1.Chart);            //Populate it with data (here random)            line1.FillSampleValues(10);            //Add a series to be used for an Average Function            Line line2 = new Line(tChart1.Chart);            //Define the Function Type for the new Series            Steema.TeeChart.Functions.Average average1 = new Steema.TeeChart.Functions.Average();            line2.Function = average1;            //Define the Datasource for the new Function Series            line2.DataSource = line1;            //*Note - When populating your input Series manually you will need to             //use the Checkdatasource method             //- See the section entitled 'Defining a Datasource'            //Change the Period of the Function so that it groups averages            //every 2 Points            line2.Function.Period = 2;            line2.CheckDataSource();

[VB.Net]

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load        'Add a data Series        Dim Line1 As New Steema.TeeChart.Styles.Line(TChart1.Chart)         'Populate it with data (here random)        Line1.FillSampleValues(10)        'Add a series to be used for an Average Function        Dim Line2 As New Steema.TeeChart.LineSeries(TChart1.Chart)        'Define the Function Type for the new Series        Dim Average1 As New Steema.TeeChart.Functions.Average()        Line2.Function = Average1        'Define the Datasource for the new Function Series        Line2.DataSource = Line1        '*Note - When populating your input Series manually you will need to         'use the Checkdatasource method         '- See the section entitled 'Defining a Datasource'        'Change the Period of the Function so that it groups averages        'every 2 Points        Line2.Function.Period = 2        Line2.CheckDataSource()End Sub

添加另一个函数来获取有关前一个函数的信息

[C#.Net]

private void button1_Click(object sender, System.EventArgs e)             //Let's change to 2D for visibility            tChart1.Aspect.View3D = false;            //Add another Series to be used for a 2nd Function             Line line3 = new Line(tChart1.Chart);            //Define the Function Type for the new Series             Steema.TeeChart.Functions.High high1 = new Steema.TeeChart.Functions.High();            line3.Function = high1;            //Define the Datasource for the new Function Series             //Use the existing Function (Series2) as input             line3.DataSource = tChart1.Series[1];            //Leave the Period at default 0 (No Period set) to draw             //A line at Highest of all points of the Average Function

[VB.Net]

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click        'Let's change to 2D for visibility        TChart1.Aspect.View3D = False        'Add another Series to be used for a 2nd Function         Dim Line3 As New Steema.TeeChart.LineSeries(TChart1.Chart)        'Define the Function Type for the new Series         Dim High1 As New Steema.TeeChart.Functions.High()        Line3.Function = High1        'Define the Datasource for the new Function Series         'Use the existing Function (Series2) as input         Line3.DataSource = TChart1.Series(1)        'Leave the Period at default 0 (No Period set) to draw         'A line at Highest of all points of the Average Function End Sub

1.2 定义数据源

例;

[C#.Net]

private void Form1_Load(object sender, System.EventArgs e)             tChart1.Aspect.View3D = false;            bar1.FillSampleValues(10);            bar2.FillSampleValues(10);         private void button1_Click(object sender, System.EventArgs e)             Steema.TeeChart.Styles.Line line1 = new Steema.TeeChart.Styles.Line(tChart1.Chart);            Steema.TeeChart.Functions.Average average1 = new Steema.TeeChart.Functions.Average();             line1.DataSource = new object[]  this.bar2,this.bar1;            line1.Function = average1;            line1.Marks.Visible = true;

[VB.Net]

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load        TChart1.Aspect.View3D = False        Bar1.FillSampleValues(10)        Bar2.FillSampleValues(10)End SubPrivate Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click        Dim DataSource As New ArrayList()        DataSource.Add(Bar1)        DataSource.Add(Bar2)        Dim Line1 As New Steema.TeeChart.Styles.Line(TChart1.Chart)        Dim Average1 As New Steema.TeeChart.Functions.Average()        Line1.Function = Average1        Line1.DataSource = DataSourceEnd Sub

为2系列添加点数：

[C#.Net]

private void button2_Click(object sender, System.EventArgs e)             Random rnd = new Random();            for(int i = 0; i < 10; ++i)                     bar1.Add(rnd.Next(500));                bar2.Add(rnd.Next(500));

[VB.Net]

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click        Dim rnd As New Random()        Dim i As Integer        For i = 0 To 10            Bar1.Add(rnd.Next(500))            Bar2.Add(rnd.Next(500))        NextEnd Sub

请注意，该功能不会显示，需要在Button2_Click（）事件中添加Series.CheckDatasource方法以读取Function的值。

[C#.Net]

tChart1.Series [2] .CheckDataSource（）; 

[VB.Net]

TChart1.Series（2）.CheckDataSource（）

可以在运行时更改函数定义，只需重新定义Series.DataSource属性即可为系列分配新函数：

[C#.Net]

private void button3_Click(object sender, System.EventArgs e)             Steema.TeeChart.Functions.Cumulative cumulative1 = new Steema.TeeChart.Functions.Cumulative();            tChart1.Series[2].Function = cumulative1;

[VB.Net]

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click        Dim Cumulative1 As New Steema.TeeChart.Functions.Cumulative()        TChart1.Series(2).Function = Cumulative1End Sub

1.3 功能周期

周期是使用函数的重要属性，因为周期定义了循环应用函数的点的范围。

示例

有6个数据点（例如条形系列的条形），其值为： 3,8,6,2,9和12。定义一个具有周期0的函数系列（默认），绘制的平均值为：6.667。将周期设置为2我们得到3个平均值作为函数的输出：5.5,4和10.5。这些值将在它们的周期范围中集中绘制，即输入系列的第1和第2条之间的第1个值，第3和第4个条之间的第2个值等..通过在“Datasource”页面中选择相关的“Series and Function”并单击“Options”选项卡来定义“Period ”，也可以使用“FunctionType”在运行时修改“Period ”。

例如，line1是函数系列：

[C#.Net]

line1.Function.Period = 2;

[VB.Net]

Line1.Function.Period = 2

下面是2个图表突出显示应用的周期

1.4 时间段样式

周期的效果可以定义为范围，这在使用DateTime系列时非常有用，将函数的“Period”表示为TimeStep，属性“PeriodStyle”控制如何表达“Period”。例如，可以使用日期时间源系列上的常规“Average”功能绘制“monthly average of sales”功能，并将功能期间设置为“one month”：

[C#.Net]

private void Form1_Load(object sender, System.EventArgs e)             //Add in a BarSeries and Average Function at design-time.            Random rnd = new Random();            tChart1.Aspect.View3D = false;                TimeSpan month = new TimeSpan(30,0,0,0);            DateTime today = DateTime.Today;            bar1.Marks.Visible = false;            bar1.XValues.DateTime = true;            tChart1.Axes.Bottom.Labels.Angle = 90;            for(int i = 0; i < 60; ++i)                 today = today.AddDays(5);                bar1.Add(today, rnd.Next(100),"",Color.Red);             average1.PeriodAlign = Steema.TeeChart.Functions.PeriodAligns.First;            average1.PeriodStyle = Steema.TeeChart.Functions.PeriodStyles.Range;            average1.Period = month.TotalDays;            line1.DataSource = bar1;            line1.CheckDataSource();

[VB.Net]

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load        'Add in a BarSeries and Average Function at design-time.        TChart1.Aspect.View3D = False        Dim Month As New TimeSpan(30, 0, 0, 0)        Dim Today As DateTime = DateTime.Today        Dim i As Integer        Bar1.Marks.Visible = False        Bar1.XValues.DateTime = True        TChart1.Axes.Bottom.Labels.Angle = 90        For i = 0 To 60            Today = Today.AddDays(5)            Bar1.Add(Today, Rnd() * 100, "", Color.Red)        Next        Average1.PeriodAlign = Steema.TeeChart.Functions.PeriodAligns.First        Average1.PeriodStyle = Steema.TeeChart.Functions.PeriodStyles.Range        Average1.Period = Month.TotalDays        Line1.DataSource = Bar1        Line1.CheckDataSource()End Sub

这将产生几个点，每个点显示BarSeries中每个月数据的“average”，在计算日期时间段的函数时，必须按源日期对源系列中的点进行排序，该范围也可用于非日期时间序列：

[C#.Net]

for(int i = 0; i < 60; ++i)      bar1.Add(Convert.ToDouble(i), rnd.Next(100),"",Color.Red);average1.PeriodAlign = Steema.TeeChart.Functions.PeriodAligns.First;average1.PeriodStyle = Steema.TeeChart.Functions.PeriodStyles.Range;average1.Period = 6;

[VB.Net]

For i = 0 To 60   Bar1.Add(i, Rnd() * 100, "", Color.Red)NextAverage1.PeriodAlign = Steema.TeeChart.Functions.PeriodAligns.FirstAverage1.PeriodStyle = Steema.TeeChart.Functions.PeriodStyles.RangeAverage1.Period = 6

这将计算每个“6”区间内每组点的平均值。（X > = 6，X < 6的点将用于计算第一个平均值，X> = 6的点，X < 12将用于计算第二个平均值，依此类推……），这与计算每6个点的平均值不同。使用“周期对齐”属性可以对齐“系列”范围内的功能点，以下将绘制每月结束时的功能点：

[C#.Net]

average1.PeriodAlign = Steema.TeeChart.Functions.PeriodAligns.First;average1.PeriodStyle = Steema.TeeChart.Functions.PeriodStyles.Range;average1.Period = month.TotalDays;

[VB.Net]

Average1.PeriodAlign = Steema.TeeChart.Functions.PeriodAligns.FirstAverage1.PeriodStyle = Steema.TeeChart.Functions.PeriodStyles.RangeAverage1.Period = Month.TotalDays

Period = Month.TotalDays and PeriodAligns.First，从下图中可以看出，“average”是在月末绘制的。

Period = Month.TotalDays and PeriodAligns.Last，在这种情况下，“average”是在月初绘制的。

1.5 派生自定义函数

创建新的Function组件只是创建一个派生自Function类的新组件（它也可以从现有的函数类派生），Function中有两个重要的虚拟方法可以重写以创建新的Function类型。 1）Function.Calculate：public virtual double Calculate（Series Source，int First，int Last） 2）Function.CalculateMany：public virtual double CalculateMany（ArrayList SourceSeries，int ValueIndex） 如果只有一个系列用作数据源，则Calculate方法用于计算函数结果。如果多个系列可用作数据源，则CalculateMany用于计算函数结果。

示例：创建新的SquareSum功能，需要一个SquareSum函数来返回“sum of squares（平方和）”，此函数只能有一个数据源或多个数据源，因此我们将覆盖Calculate和CalculateMany方法。

[C#.Net]

public class SquareSum : Steema.TeeChart.Functions.Function         public SquareSum(): base()         public SquareSum(Steema.TeeChart.Chart c): base(c)         public override double Calculate(Series SourceSeries,int FirstIndex,int LastIndex)            ValueList v=ValueList(SourceSeries);            if ( FirstIndex==-1 ) return v.Total;            else                 double result=0;                for (int t=FirstIndex; t<=LastIndex; t++)                    result+=Math.Sqrt(v[t]);                return result;          public override double CalculateMany(ArrayList SourceSeriesList,int ValueIndex)             ValueList v;            double result=0;            for (int t=0; tValueIndex )                    result+=Math.Sqrt(v[ValueIndex]);                 return result;

[VB.Net]

Public Class SquareSum        Inherits Steema.TeeChart.Functions.Function        Public Sub New()            MyBase.New()        End Sub        Public Sub New(ByVal c As Steema.TeeChart.Chart)            MyBase.New(c)        End Sub        Public Overrides Function Calculate(ByVal Source As Steema.TeeChart.Series, ByVal First As Integer, ByVal Last As Integer) As Double            Dim v As Steema.TeeChart.ValueList            Dim t As Integer            v = ValueList(Source)            If First = -1 Then                Return v.Total            Else                Dim Result As Double = 0                For t = First To t < Last                    Result += Math.Sqrt(v(t))                Next                Return Result            End If        End Function        Public Overrides Function CalculateMany(ByVal SourceSeries As System.Collections.ArrayList, ByVal ValueIndex As Integer) As Double            Dim v As Steema.TeeChart.ValueList            Dim Result As Double = 0            Dim t As Integer            For t = 0 To t < SourceSeries.Count                v = ValueList(CType(SourceSeries(t), Steema.TeeChart.Series))                If v.Count > ValueIndex Then                    Result += Math.Sqrt(v(ValueIndex))                End If            Next            Return Result        End FunctionEnd Class

FirstIndex和EndIndex变量用于“loop（循环）”所有SourceSeries点以计算平方和。“ValueList”方法用于提取必需的Steema.TeeChart.ValueList，以使这些类与HorizBarSeries等Series类型一起使用，其中“XValues”保存点值而不是“YValues”，当Series只有一个Series作为DataSource时，使用“Calculate”方法，当Series有多个Series作为数据源时，将调用“CalculateMany”方法。对于源系列中的每个点，“CalculateMany”将被调用一次，从零开始，以所有数据源的最小点数结束。理解Calculate和CalculateMany之间的区别非常重要，当只有一个数据源并且只调用一次时调用“Calculate”。当有多个Series作为数据源时，会多次调用“CalculateMany”（每个点一个）。

标签：图表Teechart pro v8teechart