Attribute VB_Name = "Module2"
'*****************************************************
'* Demonstration of module Gr2D.bas - A test periodic*
'* signal is drawn with manual scales.               *
'*                                                   *
'*    Visual Basic 4.0 Release by J-P Moreau, Paris. *
'*                 (www.jpmoreau.fr)                 *
'*****************************************************

Sub GrDemo()

 Xratio = XrIBM: Yratio = YrIBM

 Dim t As Double, ti As Double, tf As Double, dt As Double
 Dim i As Integer, ndata As Integer
 
 'Create test signal F(t)
 LogX = 0: LogY = 0: EchAuto = 1
 ti = 0#: tf = 0.2
 ndata = InputBox("Input number of points:", "DATA", "1024")
 ReDim V(ndata)
 dt = (tf - ti) / (ndata - 1)
 t = ti - dt
 For i = 0 To ndata - 1
   t = t + dt
   V(i) = Curve#(t)
 Next

 'Draw a test curve with manual scales
 Form1.AutoRedraw = False
 Form1.Cls
 
 'prepare graph
 Fenetre ti, tf, -100#, 100#             'window in physical coordinates
 Cloture 750, MaxX, 0, MaxY - 500        'screen window in pixels
 Grid 0.02, 10#                          'draw grid
 Graduate 0.04, 20#                      'graduate axes
 Axes                                    'draw axes
 Bordure                                 'draw frame
 
 'draw curve (ndata points)
 MoveXY ti, V(1)
 t = ti
 For i = 2 To ndata - 1
   t = t + dt
   LineXY t, V(i)
 Next i
 
 'print graph caption and names of axes
 Form1.Font.Bold = True
 Form1.Font.Size = 14
 Display 4500, 50, "TEST SIGNAL"
 Form1.Font.Size = 10
 Display 900, 550, "Acc. m/s2"
 Display MaxX - 1250, MaxY - 400, "Time sec."
 'print number of points
 Form1.Font.Bold = False
 S$ = Str$(ndata) & " points."
 Display 900, MaxY - 650, S$
 
 Form1.Command1.Caption = "Continue"
 
 End Sub

Function Curve#(t As Double)
Dim pi As Double
  pi = 3.1415926535
  Curve# = 10 * Sin(2 * pi * 50 * t) + 20 * Sin(2 * pi * 250 * t) + 50 * Sin(2 * pi * 500 * t)
End Function