Plot graph

Here's good place to start....

Instructions:

Make a large form 800 x 600

Place a large Picture box in it (700 x 500)

Name the picturebox “pb1” – make its backcolor black

(I think you could use a panel here too)

Make a button at the bottom. Name it “cbGo”

Make a second button at the bottom named “cbExit”

I have done my best to deal with continuation lines and the

Distortion of this board but I may have missed.

Play with it J

Imports System.Drawing

Public Class Form1

Protected g As Graphics

Protected a As GraphClass

Protected firsttime As Boolean

Protected Enum FrameCoord

X_Axis_VertLoc = 400

HorizontalDisplacement = 50

Y_Axis_XEnd = 650

Y_Axis_Start = 50

X_Axis_Begin = HorizontalDisplacement

End Enum

Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

g = pb1.CreateGraphics()

a = New GraphClass(g)

End Sub

Private Sub cbGo_Click(ByVal sender As Object, _
ByVal e As System.EventArgs) Handles cbGo.Click

Static dtNow As DateTime = DateTime.Now

a.SetupFrame()

For i As Short = 0 To 649

a.PlotPoint(i, (Math.Sin(i / 57.3) * 100) + 100)

Next

End Sub

Private Sub cbExit_Click(ByVal sender As Object, _

ByVal e As System.EventArgs) Handles cbExit.Click

Application.exit

End Sub

Public Class GraphClass

Protected Gain As New Single

Private Intersection As Point = _

New Point(FrameCoord.HorizontalDisplacement, _
FrameCoord.X_Axis_VertLoc)

Protected g As Graphics ' picture box graphic

Protected AxisColor As Color = _
System.Drawing.ColorTranslator.FromOle(&HFF00)

Protected AxisPen As Pen

Public Sub New(ByVal obj As Graphics)

' this graphics is derived from a picture box object in the
‘substantiator

Gain = 1.0

g = obj

AxisPen = New Pen(AxisColor, 2)

End Sub

Public Sub SetupFrame()

Dim pY_Begin As _

New Point(FrameCoord.HorizontalDisplacement, _
FrameCoord.Y_Axis_Start)

Dim pY_End As New Point(FrameCoord.HorizontalDisplacement, _
FrameCoord.X_Axis_VertLoc)

Dim pX_Begin As Point = Intersection

Dim pX_End As New Point(FrameCoord.Y_Axis_XEnd, _
FrameCoord.X_Axis_VertLoc)

' Draw line to screen.

Drawline(AxisPen, pY_Begin, pY_End)

Drawline(AxisPen, pX_Begin, pX_End)

For i As Short = FrameCoord.HorizontalDisplacement + 50 _

To FrameCoord.Y_Axis_XEnd Step 50

Drawline(Pens.BlanchedAlmond, New Point(i, _
FrameCoord.X_Axis_VertLoc - 10), New Point(i, _
FrameCoord.X_Axis_VertLoc))

Next

For i As Short = FrameCoord.X_Axis_VertLoc - 50 To _
FrameCoord.Y_Axis_Start Step -50

Drawline(Pens.BlanchedAlmond, _

New Point(FrameCoord.HorizontalDisplacement, i), _

New Point(FrameCoord.HorizontalDisplacement + 10, i))

Next

End Sub

Public Sub PlotPoint(ByVal X As Integer, _

ByVal Y As Integer, _

Optional ByVal pn As Pen = Nothing)

Dim xp As Integer = (-Y + FrameCoord.X_Axis_VertLoc) * Gain

If pn Is Nothing Then

g.DrawLine(AxisPen, New Point(X + Intersection.X, xp), _
New Point(X + 1 + Intersection.X, xp + 1))

Else

g.DrawLine(pn, New Point(X + Intersection.X, xp), _
New Point(X + 1 + Intersection.X, xp + 1))

End If

End Sub

Public Sub Drawline(ByVal P As Pen, _

ByVal StartPoint As Point, _

ByVal EndPoint As Point)

If P Is Nothing Then

g.DrawLine(AxisPen, StartPoint, EndPoint)

Else

g.DrawLine(P, StartPoint, EndPoint)

End If

End Sub

End Class

End Class

ReneeC at 2007-8-31 >

I wrote this about a year ago. I imagine the the HorizontalDisplacement is the amount that the entire graph is shifted to the right and X_Axis_Verloc specifies how far down the x axis is. They all have to be positioned.

On a timer...

"a" is a member variable of the main class is accessible anywhere in the main class.

You'll notice that calculation is done in a for loop

For i As Short = 0 To 649

a.PlotPoint(i, (Math.Sin(i / 57.3) * 100) + 100)

Next

The call to a.PlotPoint could easily be made in a timer tick event in the main class. "i" is x coordinate and the Y coordinate is the sine value which could be what ever you are measuring.

Protected Friend withevents tmr as new timer - up with the instantiation of "a".

then make a tick event for it.

It's easy!

ReneeC at 2007-8-31 >

i think i now understand what does every part do for the graph, only this following section that im a bit confused about, i hope that you can give me some brief or rough explanation regarding it, thanks a lot..

Public Sub PlotPoint(ByVal X As Integer, _

ByVal Y As Integer, _

Optional ByVal pn As Pen = Nothing)

Dim xp As Integer = (-Y + FrameCoord.X_Axis_VertLoc) * Gain

If pn Is Nothing Then

g.DrawLine(AxisPen, New Point(X + Intersection.X, xp), _
New Point(X + 1 + Intersection.X, xp + 1))

Else

g.DrawLine(pn, New Point(X + Intersection.X, xp), _
New Point(X + 1 + Intersection.X, xp + 1))

End If

End Sub

wencey at 2007-8-31 >

I posted it wrongly, so i post this again:

i think i now understand what does every part do for the graph, only this following section that im a bit confused about, i hope that you can give me some brief or rough explanation regarding it, thanks a lot..

Public Sub PlotPoint(ByVal X As Integer, _

ByVal Y As Integer, _

Optional ByVal pn As Pen = Nothing)

Dim xp As Integer = (-Y + FrameCoord.X_Axis_VertLoc) * Gain

If pn Is Nothing Then

g.DrawLine(AxisPen, New Point(X + Intersection.X, xp), _
New Point(X + 1 + Intersection.X, xp + 1))

Else

g.DrawLine(pn, New Point(X + Intersection.X, xp), _
New Point(X + 1 + Intersection.X, xp + 1))

End If

End Sub

wencey at 2007-8-31 >

Im trying to play around with the timer, and wanted to plot a point from 0 to 649 with one second each but it doesnt work.

Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick

Timer1.Interval = 1000

For i As Short = 0 To 649

a.PlotPoint(i, (Math.Sin(i / 57.3) * 100) + 100)

Next

End Sub

wencey at 2007-8-31 >