ChartDirector 6.0 (ASP/COM/VB Edition)

Start Angle and Direction


  

This example demonstrates different sector layout angles and directions.

By default, ChartDirector positions sectors starting from the upward pointing position, and in clockwise direction.

The start angle and layout direction can be changed using PieChart.setStartAngle.

One common application for PieChart.setStartAngle is to facilitate layout of pie charts containing many small sectors. Please refer to Side Label Layout for an example.

Source Code Listing

[Web Version (in ASP)] aspdemo\anglepie.asp
<%@ language="vbscript" %>
<%
Set cd = CreateObject("ChartDirector.API")

' This script can draw different charts depending on the chartIndex
chartIndex = CInt(Request("img"))

' The data for the pie chart
data = Array(25, 18, 15, 12, 8, 30, 35)

' The labels for the pie chart
labels = Array("Labor", "Licenses", "Taxes", "Legal", "Insurance", "Facilities", "Production")

' Create a PieChart object of size 280 x 240 pixels
Set c = cd.PieChart(280, 240)

' Set the center of the pie at (140, 130) and the radius to 80 pixels
Call c.setPieSize(140, 130, 80)

' Add a title to the pie to show the start angle and direction
If chartIndex = 0 Then
    Call c.addTitle("Start Angle = 0 degrees<*br*>Direction = Clockwise")
Else
    Call c.addTitle("Start Angle = 90 degrees<*br*>Direction = AntiClockwise")
    Call c.setStartAngle(90, False)
End If

' Draw the pie in 3D
Call c.set3D()

' Set the pie data and the pie labels
Call c.setData(data, labels)

' Explode the 1st sector (index = 0)
Call c.setExplode(0)

' Output the chart
Response.ContentType = "image/png"
Response.BinaryWrite c.makeChart2(cd.PNG)
Response.End
%>

[Windows Version (in Visual Basic)] vbdemo\anglepie.cls
Public Sub createChart(viewer As Object, chartIndex As Integer)

    Dim cd As New ChartDirector.API

    ' The data for the pie chart
    Dim data()
    data = Array(25, 18, 15, 12, 8, 30, 35)

    ' The labels for the pie chart
    Dim labels()
    labels = Array("Labor", "Licenses", "Taxes", "Legal", "Insurance", "Facilities", "Production")

    ' Create a PieChart object of size 280 x 240 pixels
    Dim c As PieChart
    Set c = cd.PieChart(280, 240)

    ' Set the center of the pie at (140, 130) and the radius to 80 pixels
    Call c.setPieSize(140, 130, 80)

    ' Add a title to the pie to show the start angle and direction
    If chartIndex = 0 Then
        Call c.addTitle("Start Angle = 0 degrees<*br*>Direction = Clockwise")
    Else
        Call c.addTitle("Start Angle = 90 degrees<*br*>Direction = AntiClockwise")
        Call c.setStartAngle(90, False)
    End If

    ' Draw the pie in 3D
    Call c.set3D()

    ' Set the pie data and the pie labels
    Call c.setData(data, labels)

    ' Explode the 1st sector (index = 0)
    Call c.setExplode(0)

    ' Output the chart
    Set viewer.Picture = c.makePicture()

    'include tool tip for the chart
    viewer.ImageMap = c.getHTMLImageMap("clickable", "", _
        "title='{label}: US${value}K ({percent}%)'")

End Sub