📄 常微分~2.frm
字号:
VERSION 5.00
Begin VB.Form 常微分方程
BackColor = &H00FFFF80&
Caption = "Form1"
ClientHeight = 8355
ClientLeft = 135
ClientTop = 405
ClientWidth = 12195
LinkTopic = "Form1"
ScaleHeight = 8355
ScaleWidth = 12195
StartUpPosition = 3 '窗口缺省
Begin VB.ListBox List6
Height = 240
Left = 4800
TabIndex = 12
Top = 6960
Width = 2412
End
Begin VB.ListBox List5
Height = 240
Left = 2160
TabIndex = 11
Top = 6960
Width = 1932
End
Begin VB.ListBox List4
Height = 240
Left = 4800
TabIndex = 10
Top = 6600
Width = 2412
End
Begin VB.ListBox List3
Height = 240
Left = 2160
TabIndex = 9
Top = 6600
Width = 1932
End
Begin VB.ListBox List2
Height = 240
Left = 4800
TabIndex = 8
Top = 6240
Width = 2412
End
Begin VB.ListBox List1
Height = 240
Left = 2160
TabIndex = 7
Top = 6240
Width = 1932
End
Begin VB.CommandButton Command6
Caption = "退出"
Height = 612
Left = 120
TabIndex = 6
Top = 4800
Width = 1452
End
Begin VB.CommandButton Command5
Caption = "重新运行"
Height = 612
Left = 120
TabIndex = 5
Top = 3840
Width = 1452
End
Begin VB.CommandButton Command4
Caption = "四阶龙库塔法"
Height = 612
Left = 120
TabIndex = 4
Top = 3000
Width = 1452
End
Begin VB.CommandButton Command3
Caption = "改进欧拉法"
Height = 612
Left = 120
TabIndex = 3
Top = 2160
Width = 1452
End
Begin VB.CommandButton Command2
Caption = "欧拉法"
Height = 612
Left = 120
TabIndex = 2
Top = 1320
Width = 1452
End
Begin VB.CommandButton Command1
Caption = "产生坐标系"
Height = 612
Left = 120
TabIndex = 1
Top = 480
Width = 1452
End
Begin VB.PictureBox Picture1
BackColor = &H00FFFFC0&
Height = 5172
Left = 1920
ScaleHeight = 5115
ScaleWidth = 7755
TabIndex = 0
Top = 360
Width = 7812
End
Begin VB.Label Label5
Caption = "y1"
Height = 252
Left = 5400
TabIndex = 17
Top = 5880
Width = 732
End
Begin VB.Label Label4
Caption = "x1"
Height = 252
Left = 2640
TabIndex = 16
Top = 5880
Width = 732
End
Begin VB.Label Label3
Caption = "四阶龙库塔法："
Height = 252
Left = 600
TabIndex = 15
Top = 6960
Width = 1212
End
Begin VB.Label Label2
Caption = "改进欧拉法"
Height = 252
Left = 600
TabIndex = 14
Top = 6600
Width = 1212
End
Begin VB.Label Label1
Caption = "欧拉法"
Height = 252
Left = 600
TabIndex = 13
Top = 6228
Width = 1212
End
End
Attribute VB_Name = "常微分方程"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Private Sub Command1_Click()
Command1.Enabled = False
Call zuobiao
Command2.Enabled = True
Command3.Enabled = True
Command4.Enabled = True
Command5.Enabled = True
Command6.Enabled = True
End Sub
Private Function zuobiao()
Picture1.DrawWidth = 2
Picture1.ScaleMode = 6
Picture1.Line (8, 8)-(8, 80), vbRed
Picture1.Line (8, 80)-(130, 80), vbRed
Picture1.Line (7, 11)-(8, 8), vbRed
Picture1.Line (9, 11)-(8, 8), vbRed
Picture1.Line (128, 79)-(130, 80), vbRed
Picture1.Line (128, 81)-(130, 80), vbRed
Picture1.ForeColor = vbRed
Picture1.FontBold = True
Picture1.FontSize = 18
Picture1.CurrentX = 3: Picture1.CurrentY = 6
Picture1.Print "Y"
Picture1.CurrentX = 3: Picture1.CurrentY = 80
Picture1.Print "O"
Picture1.CurrentX = 128: Picture1.CurrentY = 82
Picture1.Print "X"
End Function
Private Sub Command2_Click()
Command2.Enabled = False
Call euler
End Sub
Private Sub Command3_Click()
Command3.Enabled = False
Call improveeuler
End Sub
Private Sub Command4_Click()
Command4.Enabled = False
Call runge_kutta
End Sub
Private Sub Command5_Click()
Picture1.Cls
Command1.Enabled = True
Command2.Enabled = False
Command3.Enabled = False
Command4.Enabled = False
Command5.Enabled = False
Command6.Enabled = True
End Sub
Private Sub Command6_Click()
常微分方程.Hide
Form1.Show
End Sub
Private Sub form_load()
Form1.Left = 200
Form1.Top = 250
End Sub
Public Function delay(ByVal m As Integer)
Dim i%, j%
For i = 0 To 9999
For j = 0 To m
Next
Next
End Function
Public Function euler()
Dim x0#, y0#, n%, N1%, h#, x1#, y1#, Y#, k#
x0 = InputBox("请输入x0:", "直接欧拉法", 0)
y0 = InputBox("请输入y0:", "直接欧拉法", 1)
h = InputBox("请输入步长h:", "直接欧拉法", 0.1, 0.01)
n = 1
For x = 0 To 2 Step h
x1 = x0 + h
y1 = y0 + h * (-y0 - x0 * y0 ^ 2)
CurrentX = 8 + 30 * (x0 + h): CurrentY = 80
Picture1.Line (x0 * 30 + 8, 80 - y0 * 30)-(x1 * 30 + 8, 80 - y1 * 30), vbYellow
Call delay(100)
List1.AddItem (x1): List2.AddItem (y1)
n = n + 1
x0 = x1
y0 = y1
Next
End Function
Public Function improveeuler()
Dim x0#, y0#, yp#, yc#, n%, N1%, h#, x1#, y1#
x0 = InputBox("请输入x0:", "改进欧拉法", 0)
y0 = InputBox("请输入y0:", "改进欧拉法", 1)
h = InputBox("请输入步长h:", "改进欧拉法", 0.1, 0.01)
n = 1
For x = 0 To 2 Step h
x1 = x0 + h
yp = y0 + h * (-y0 - x0 * y0 ^ 2)
yc = y0 + h * (-yp - x1 * yp ^ 2)
y1 = (yp + yc) / 2
CurrentX = 8 + 30 * (x0 + h): CurrentY = 80
Picture1.Line (x0 * 30 + 8, 80 - y0 * 30)-(x1 * 30 + 8, 80 - y1 * 30), vbBlue
Call delay(100)
List3.AddItem (x1): List4.AddItem (y1)
n = n + 1
x0 = x1
y0 = y1
Next
End Function
Public Function runge_kutta()
Dim x0#, y0#, k1#, k2#, k3#, k4#, n%, N1%, h#, x1#, y1#
x0 = InputBox("请输入x0:", "四阶龙库塔", 0)
y0 = InputBox("请输入y0:", "四阶龙库塔", 1)
h = InputBox("请输入步长h:", "四阶龙库塔", 0.1, 0.01)
n = 1
For x = 0 To 2 Step h
x1 = x0 + h
k1 = -y0 - x0 * y0 * y0
k2 = -(y0 + k1 * h / 2) - (x0 + h / 2) * (y0 + k1 * h / 2) ^ 2
k3 = -(y0 + k2 * h / 2) - (x0 + h / 2) * (y0 + k2 * h / 2) ^ 2
k2 = -(y0 + k3 * h / 2) - x1 * (y0 + k3 * h / 2) ^ 2
y1 = y0 + (k1 + 2 * k2 + 2 * k3 + k4) * h / 6
CurrentX = 8 + 30 * (x0 + h): CurrentY = 80
Picture1.Line (x0 * 30 + 8, 80 - y0 * 30)-(x1 * 30 + 8, 80 - y1 * 30), vbRed
Call delay(100)
List5.AddItem (x1): List6.AddItem (y1)
n = n + 1
x0 = x1
y0 = y1
Next
End Function
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -