Полный код программы

Imports System.Math

Imports System.Drawing, System.Drawing.Text

Public Class Form1

Inherits System.Windows.Forms.Form

Dim a As Single, b As Single, id As Boolean

Dim eps As Single

Dim nf As Integer

Private Sub btnВычислить_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnВычислить.Click

Dim xw As Single, it As Integer

Dim Flag As Boolean

lblРезультаты.Visible = False

lblГрафик.Visible = False

lblИтерации.Visible = False

lblКорень.Visible = False

id = False

Try

a = CSng(txta.Text)

Catch

MsgBox("Введенное значение a не число? Поправьте!")

Exit Sub

End Try

Try

b = CSng(txtb.Text)

Catch

MsgBox("Введенное значение b не число? Поправьте!")

Exit Sub

End Try

Try

eps = CSng(txteps.Text)

Catch

MsgBox("Введенное значение eps не число? Поправьте!")

Exit Sub

End Try

' Проверка корректности данных

If a >= b Then

MsgBox("Нарушено условие a < b? Поправьте!")

Exit Sub

End If

If eps <= 0 Then

MsgBox("Допустимая ошибка eps <= 0? Поправьте!")

Exit Sub

End If

id = True

' Вычисление корня

koren(100, a, b, eps, xw, it, Flag)

' Вывод результатов вычислений

If Flag Then

lblКорень.ForeColor = Color.Red

lblКорень.Text = "Решение не получено!"

lblКорень.Visible = True

'Запись в файл

PrintLine(nf, "Решение не получено!")

Else: lblИтерации.Text = "Решение получено! Выполнено " & it.ToString & " итераций"

lblКорень.ForeColor = Color.Black

lblКорень.Text = "Значение корня = " & Format(xw, "0.#######")

lblКорень.Visible = True

lblИтерации.Visible = True

lblГрафик.Visible = True

'Запись в файл

PrintLine(nf, a, b, eps, it, xw)

End If

pbxГрафик.Invalidate()

End Sub

Private Sub btnВыход_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnВыход.Click

FileClose(nf)

End

End Sub

Private Function f1(ByVal x As Single) As Single

f1 = 1/(3+Sin3,6x) - x

End Function

Private Function f2(ByVal x As Single) As Single

f2 = 1/(3+Sin3,6x)

End Function

Private Sub koren(ByVal pred As Integer, ByVal a As Single, ByVal b As Single, ByVal eps As Single, ByRef xw As Single, ByRef it As Integer, ByRef Flag As Boolean)

Dim xn1 As Single, xs As Single

Dim fxn1 As Single, fxn2 As Single

Dim d As Single, Bool As Boolean

xn1 = (a + b) / 2

it = 0

fxn1 = f1(xn1)

fxn2 = f2(xn1)

Do

xs = f2 ( xn1 )

it = it + 1

d = xs - xn1

xn1 = xs

Bool = Abs(d) < eps Or it >= pred

Loop Until Bool

If it <= pred Then

Flag = False

xw = xs

Else

Flag = True

End If

End Sub

Private Sub pbxГрафик_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles pbxГрафик.Paint

Dim x, ab, dx As Single

Dim i, n As Integer

n = 10

ab = b - a

dx = ab / n

If id Then

Dim mx As Single

Dim sx, sy, rx, ry, h, w As Integer

h = pbxГрафик.Height

w = pbxГрафик.Width

mx = 0.9 * w / ab

sx = w * (0.05 - 0.9 * a / ab)

sy = h / 2

Dim G As Graphics

G = e.Graphics

G.TranslateTransform(sx, sy)

G.ScaleTransform(mx, mx)

Dim P1, P2 As Pen

P1 = New Pen(Color.Black, 1 / mx)

P2 = New Pen(Color.Red, 1 / mx)

Dim x1, x2, y1, y2 As Single

x1 = a - 0.02 * ab

y1 = 0

x2 = b + 0.02 * ab

y2 = 0

G.DrawLine(P1, x1, y1, x2, y2)

x1 = 0

y1 = -h / 2 + 0.01 * mx

x2 = 0

y2 = h / 2 - 0.01 * mx

G.DrawLine(P1, x1, y1, x2, y2)

x1 = a

y1 = f1(x1)

x2 = x1 + dx

y2 = f1(x2)

For i = 1 To n

G.DrawLine(P2, x1, y1, x2, y2)

x1 = x2

y1 = y2

x2 = x2 + dx

y2 = f1(x2)

Next

Dim ШагШкалы As Single

ШагШкалы = CInt(ab) / 10

For x = CInt(a * 10) / 10 To b + ШагШкалы / 2 Step ШагШкалы

G.DrawLine(P1, x, -CSng(ab / 100), x, CSng(ab / 100))

Dim fnt As New Font("Times New Roman", 7 / mx, FontStyle.Regular)

Dim Br As New SolidBrush(Color.Black)

G.DrawString(Format(x, "0.0"), fnt, Br, x, ab / 100)

Next

End If

End Sub

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

nf = FreeFile()

FileOpen(nf, "D:\Аляутдинов\frz.txt", OpenMode.Output)

PrintLine(nf, "a", "b", "Доп. ошибка", "Вып. итераций", "Знач. корня")

FileClose(nf)

nf = FreeFile()

FileOpen(nf, "D:\Аляутдинов\frz.txt", OpenMode.Append)

End Sub

Дата добавления: 2015-08-02