Computer Programming Concepts and Visual Basic David I. Schneider

274 Computer Programming Concepts and Visual Basic
picPop.CurrentX = .7 ‘Beginning horizontal position of
label for CA
picPop.Print “California”; ‘Beginning horizontal position of
label for NY
picPop.CurrentX = 1.7 picPop.Print “New York”;
End Sub
FIGURE 9-14 Coordinates of Principal Points of Example 1
Any program that draws a line chart can be easily modified to produce a bar chart. Multiple
line charts are converted into so-called clustered bar charts.
EXAMPLE 2
Display the 2-year college enrollments for males and females in a clustered bar chart. Use the data in
Table 9.2 of Section 9.4.
SOLUTION:
The output of the following program appears in Figure 9-15. This program is very similar to the program
that produced Figure 9-11 of Section 9.4.
Private Sub cmdDraw_Click()
Dim numYears As Integer, maxEnroll As Single
‘Bar Chart of Total Two-Year College Enrollments
numYears = 5
ReDim label(1 To numYears) As String
ReDim male(1 To numYears) As Single
ReDim female(1 To numYears) As Single
Call ReadData(label(), male(), female(), numYears, maxEnroll)
Call DrawAxes(numYears, maxEnroll)
Call DrawData(male(), female(), numYears)
Call ShowTitle(maxEnroll)
Call ShowLabels(label(), numYears, maxEnroll)
Call ShowLegend(maxEnroll)
End Sub
Private Sub
DrawAxes(numYears As Integer, maxEnroll As Single)
‘Draw axes
picEnroll.Scale (-1, 1.2 * maxEnroll)-(numYears + 1, -.2 * maxEnroll)
picEnroll.Line (-1, 0)-(numYears + 1, 0)
picEnroll.Line (0, -.1 * maxEnroll)-(0, 1.1 * maxEnroll)
End Sub