With GoDB you can construct graphs and charts- both static and dynamic quite easily and pep up your data presentation. This article will touch the shallow waters of charting with static data. End of the article there is a link to download the source code for this charting application.

First some definitions:

''*****************************************************************
''''SOME VARIABLES THAT CAN BE INCLUDED IN THE QUERY STRING ARE

'XMargin = 20 MARGIN WIDTH BETWEEN COORDINATES IN X LEGEND
'XOrigin = 5 STARTING X1 POSITION OF RECTANGLE
'XRange = 190 X2-530, XRANGE IS DIFF OF X1 AND X2
'XDiv = 5 NO. OF DIVISIONS IN X AXIS

'YMargin = 20 MARGIN WIDTH BETWEEN COORDINATES IN Y LEGEND
'YOrigin = 210 STARTING Y1 POSITION OF RECTANGLE
'YRange = 200 YRANGE IS DIFF OF Y1 AND Y2
'YDiv = 5 NO. OF DIVISIONS IN Y AXIS


'ShowData = 1 TO DISPLAY DATA, WHILE PLOTTING POINTS

'Type = 1 LINE CHART
'Type = 2 BAR CHART
''*****************************************************************


'XAXIS$ = LIST OF X COORDINATES
'YAXIS$ = LIST OF Y COORDINATES

'SAMPLE COORDINATES
'XAxis$ = "1999,2000,2001,2002,2003,2004,2005,2006,2007,2008, 2009"
'YAxis$ = "50.340,83,737,90.50,400,300,200,200,400, 200, 300"



Bar Chart: Drawing the rectangle bar

to draw the rectangle bar, use drawrect function

ex: drawrect(XOrigin-10,YOrigin,XRange+30,-YRange,2,0,46815,46815)

For Color coding the bar use Fillrect function

ex: fillrect(XOrigin,YOrigin,XRange,-YRange,46815)




Line charts:

Line charts invovle two basic components. Plotting the data and drawing line.

PLOTTING DATA

If ubound(Str$) > 0 Then
For Count = 0 to ubound(Str$)
If Count=0 Then
m1=split(arrY$,Str$(Count),",")
ElseIf Count = 1 Then
m1=split(arrY$,Str$(Count),",")
End If

for i = 0 to NoOfPoints - 1
DataX = atol(arrX$(i))
NewX = TransX(DataX, XMax, XMin)
DataY = atol(arrY$(i))
NewY = TransY(DataY, YMax, YMin)
If Request$("Type") = "1" Then
iff i>0 then drawline(NewX,NewY,OldX,OldY,1,1)
iff ShowData>0 then textout(NewX,NewY,arrY$(i),0,63504, 5)
drawrect(NewX,NewY,2,2,2,1,63488,0)
ElseIf Request$("Type") = "2" Then
iff showData>0 then textout(NewX-5,NewY-20,arrY$(i),0,63504, 5)
drawrect(NewX-5,NewY,10,YOrigin-NewY,2,1,1,255)
End If
OldX = NewX
OldY = NewY
next
Next
Else
for i = 0 to NoOfPoints - 1
DataX = atol(arrX$(i))
NewX = TransX(DataX, XMax, XMin)
DataY = atol(arrY$(i))
NewY = TransY(DataY, YMax, YMin)
If Request$("Type") = "1" Then
iff i>0 then drawline(NewX,NewY,OldX,OldY,1,1)
iff ShowData>0 then textout(NewX,NewY,arrY$(i),0,63504, 5)
drawrect(NewX,NewY,2,2,2,1,63488,0)
ElseIf Request$("Type") = "2" Then
iff showData>0 then textout(NewX-5,NewY-20,arrY$(i),0,63504, 5)
drawrect(NewX-5,NewY,10,YOrigin-NewY,2,1,1,255)
End If
OldX = NewX
OldY = NewY
next
End If

Plotting charts from dynamic data or from database shall be dealt in future articles. So expect a sequel.