Series Calculations with Loops
Code
'
' This program accepts an integer as input and then computes the value for a number of
series
'
' The input is tested to make sure it is a positive value
'
' 1. The sum = 1 + 2 + 3 + 4 + . . . N is computed by each of the three loop structures:
'
Do - While
'
Do - Until
'
For - Next
'
' 2.
Loop
' 3.
Loop
' 4.
Next
' 5.
Do ' 6.
Do '
The sum of the Odd integers 1 + 3 + 5 + 7 + . . . N is computed with a For - Next
The sum of the Even integers 2 + 4 + 6 + 8 + . . . N is computed with a For - Next
The sum of the fractions 1 + 1/2 + 1/3 + 1/4 + . . . 1/N is computed with a For Loop
All perfect squares less than N ( 1, 4, 9, 16 etc. ) are computed and printed with a
While Loop
The sum of the perfect square fractions ( 1 + 1/4 + 1/9 + . . . is computed with a
While Loop
Public Class frmSum
Private Sub btnQuit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
Handles btnQuit.Click
Close() ' NOTE: This will terminate the program just like "End"
End Sub
Private Sub btnClear_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btnClear.Click
lstOut.Items.Clear()
End Sub
Private Sub bthDoWhile_Click(sender As System.Object, e As System.EventArgs) Handles
bthDoWhile.Click
Dim terms As Integer
Dim index As Integer = 1
Dim sum As Integer = 0
If IsNumeric(txtInput.Text) Then
terms = CInt(txtInput.Text)
Else
MessageBox.Show("Invalid value in the terms textbox")
Exit Sub
End If
lstOut.Items.Add("Do While Loop")
Do While index <= terms
sum = sum + index
' MessageBox.Show("Adding term " & index & " current sum is " & sum)
index = index + 1
Loop
lstOut.Items.Add("The sum of integers 1 to " & terms & " is " & sum)
End Sub
Private Sub btnDoUntil_Click(sender As System.Object, e As System.EventArgs) Handles
btnDoUntil.Click
Dim terms As Integer
Dim index As Integer = 1
Dim sum As Integer = 0
If IsNumeric(txtInput.Text) Then
terms = CInt(txtInput.Text)
Else
MessageBox.Show("Invalid value in the terms textbox")
Exit Sub
End If
lstOut.Items.Add("Do Until Loop")
Do
sum = sum + index
' MessageBox.Show("Adding term " & index & " current sum is " & sum)
index = index + 1
Loop Until index > terms
lstOut.Items.Add("The sum of integers 1 to " & terms & " is " & sum)
End Sub
Private Sub bthForNext_Click(sender As System.Object, e As System.EventArgs) Handles
bthForNext.Click
Dim terms As Integer
Dim index As Integer = 1
Dim sum As Integer = 0
If IsNumeric(txtInput.Text) Then
terms = CInt(txtInput.Text)
Else
MessageBox.Show("Invalid value in the terms textbox")
Exit Sub
End If
lstOut.Items.Add("For Next Loop")
For index = 1 To terms
sum = sum + index
Next
lstOut.Items.Add("The sum of integers from 1 to " & terms & " is " & sum)
End Sub
Private Sub btnSumOdd_Click(sender As System.Object, e As System.EventArgs) Handles
btnSumOdd.Click
Dim index As Integer = 1
Dim terms As Integer = 0
Dim sum As Integer = 0
If IsNumeric(txtInput.Text) Then
terms = CInt(txtInput.Text)
Else
MessageBox.Show("Invalid value in the terms textbox")
Exit Sub
End If
For index = 1 To terms Step 2
sum = sum + index
Next
lstOut.Items.Add("The sum of the odd integers from 1 to " & terms & " is " & sum)
End Sub
Private Sub btnSumEven_Click(sender As System.Object, e As System.EventArgs) Handles
btnSumEven.Click
Dim index As Integer = 2
Dim terms As Integer = 0
Dim sum As Integer = 0
If IsNumeric(txtInput.Text) Then
terms = CInt(txtInput.Text)
Else
MessageBox.Show("Invalid value in the terms textbox")
Exit Sub
End If
For index = 2 To terms Step 2
sum = sum + index
Next
lstOut.Items.Add("The sum of the even integers from 2 to " & terms & " is " &
sum)
End Sub
Private Sub btnSumFractions_Click(sender As System.Object, e As System.EventArgs)
Handles btnSumFractions.Click
Dim index As Integer = 1
Dim terms As Integer = 0
Dim sum As Double = 0
If IsNumeric(txtInput.Text) Then
terms = CInt(txtInput.Text)
Else
MessageBox.Show("Invalid value in the terms textbox")
Exit Sub
End If
For index = 1 To terms
sum = sum + 1 / index
Next
lstOut.Items.Add("The sum of the fractions from 1 to 1/" & terms & " is " &
FormatNumber(sum, 4))
End Sub
Private Sub btnSquares_Click(sender As System.Object, e As System.EventArgs) Handles
btnSquares.Click
Dim index As Integer = 1
Dim terms As Integer = 0
Dim squares As Integer = 0
Dim line As String = ""
If IsNumeric(txtInput.Text) Then
terms = CInt(txtInput.Text)
Else
MessageBox.Show("Invalid value in the terms textbox")
Exit Sub
End If
Do While index ^ 2 <= terms
squares = index ^ 2
line = line & squares & " "
index = index + 1
Loop
lstOut.Items.Add(line)
End Sub
Private Sub btnSumSqFract_Click(sender As System.Object, e As System.EventArgs)
Handles btnSumSqFract.Click
Dim index As Integer = 1
Dim terms As Integer = 0
Dim sum As Double = 0
If IsNumeric(txtInput.Text) Then
terms = CDbl(txtInput.Text)
Else
MessageBox.Show("Invalid value in the terms textbox")
Exit Sub
End If
Do While index ^ 2 <= terms
sum = sum + (1 / index) ^ 2
index = index + 1
Loop
lstOut.Items.Add("The sum of the fractions squared from 1 to 1/" & terms & " is "
& FormatNumber(sum, 4))
End Sub
End Class