Imports System
Imports System.Drawing
Imports System.IO

Public Class Form1
'...
End Class

Public Class Circle2D
  ' Holds components that define a circle.

  Public Property Pt as PointF = Nothing
  Public Property Radius as Single = Nothing

  Public ReadOnly Property Rect as RectangleF
    Dim Lt as single = Pt.X - Radius
    Dim Tp as single = Pt.Y - Radius
    Dim Wt as single = Radius * 2    
    Dim Ht as single = Radius * 2

    Return new RectangleF(Lt,Tp,Wt,HT)
  End Property

  Public Sub New(Byval X as single, Byval Y as single, Byval R as single)
    ' Constructor method 
    Pt = new PointF(X,Y)
    Radius = R  
  End Sub  

End Class

Imports System
Imports System.Drawing
Imports System.IO

Public Class Form1
  Dim Circles as New list(of Circle2D)
  Dim UpdatePic as boolean = false

  Private Function TextToCircle(Byval Txt as string) as Shape_Circle

    Dim Segments() as string = Txt.Trim.Split(" "c)
    Dim X as single = Segments(0).Trim.SubString(1)  'Crop 'X' from string      
    Dim Y as single = Segments(1).Trim.SubString(1)  'Crop 'Y' from string
    Dim R as single = Segments(2).Trim.SubString(1)  'Crop 'R' from string
 
    Dim Circ as Circle2D = New Circle2D(X,Y,R)

  End Function

  ' Read text file, Translate, and Fill list
  Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
    Dim sLines() as string = File.ReadAllLines(<FilePath and Name>)

    For each sLine as string in sLines
      If sline.Startswith("X") then
        Circles.Add(TextToCircle(sLine))
      End if
    Next sLine

    UpdatePic = True
    Picturebox1.Invalidate  '<-- Tell Windows to redraw the picturebox. 
  End Sub  
End Class

'...

Public Class Form1
  '...
    
  Private Sub DrawCircles(ByRef g as Graphics)    
    with g
      For each C as Circle2D in Circles
        .DrawEllipse(Pen.Black,C.Rect)
      Next 
    End with
  End Sub
  
  Private Sub PictureBox1_Paint(sender As Object, e As System.Windows.Forms.PaintEventArgs) Handles PictureBox1.Paint
    If UpdatePic Then
      DrawCircles(e.Graphics)
    End If
  End Sub

End Class

'...

With g
  ' if your graphics represent something in the real world 
  ' then you probably want to ues Inch units.

  .PageUnit = GraphicsUnit.Inch

 
  ' The matrix defines the coordinate system to use
  ' in this case 1,0,0,-1 means a standard cartesian coordinates system
  ' where positive X is to the right and positive Y is Up.
  
  ' This differs from standard microsoft windows coordinates where 
  ' positive X is to the Right and positive Y is Down.
  ' (Add 20 to a button.Top property and the button moves down.)  


  ' The last two arguments may be used for a zoom about center if you want to zoom.
  
  Dim oMatrix As Matrix = New Matrix(1, 0, 0, -1, 0, 0)

  ' Use the scale method to adjust both x and y scale.
  ' Use variables if you want to zoom 

  oMatrix.Scale(0.5,0.5) ' <-- Double Scale I think
  
  ' Use the translate method to move the origin
  ' Use variables to Pan  

  oMatrix.Translate(o.0, -(0.0))

  ' We reset the graphics matrix to default settings before we apply
  ' our new matrix.  Remember this whole routne occurs everytime windows 
  ' refreshes the graphics.  If you are panning and zooming this is important.

  .Transform.Reset()

  ' Apply your custom matrix
  .Transform = oMatrix

  ' Get rid of jaggy graphics
  .SmoothingMode = SmoothingMode.HighQuality
End With

'...