[icomeinpieces]

i'm making a program to do binomial expansion math for me to check my math work to compare answers with

in this type of math you need to get answers for ncr equations which in involve finding out the answer to say 15! (15 * 14 * 13.... and so on)

this code here will do fine it will get my ncr math me like it will provide the answer to 3c2 which is 10 using the n! / (R1 * (n-r)!) formula but when ever i use something like 15c15 for example or anything for a r variable the "i" variable in my code which essentially represents n! will produce a overflow error. as you can see my method take 1 * 1 at first which is fine then 1* 2 *3* 4 and so on till it hits whatever value i put in the text box for it x reaches 13 and crashes with said error. now assuming i have the variables declared right and i do have code to produce the result in another text box i just didn't include it here.

so my question here is why can say a calculator like say speed crunch can handle huge numbers like that and this code can't?

 For x = 1 To Val(power.Text)
					i = i * Val(x)
				Next
				For z = 0 To Val(power.Text)
					nr = Val(power.Text) - Val(z)
					ii = 1
					ii2 = 1
					For w = 0 To Val(z)
						ii = ii * Val(w)
						If ii = 0 Then
							ii = 1
						End If
					Next
					For v = 0 To Val(nr)
						ii2 = ii2 * Val(v)
						If ii2 = 0 Then
							ii2 = 1
						End If
					Next
					p = Val(i) / (Val(ii) * Val(ii2))
					For x = 1 To Val(z)
						u = Val(power.Text) - x
						d = x
					Next
next 

[thava]

first thing is for next is not completed corrrectly
then you have to show your declaration because this will also lead some cause like this

[icomeinpieces]

thava, on 29 May, 2009 - 05:02 PM, said:

first thing is for next is not completed corrrectly
then you have to show your declaration because this will also lead some cause like this

sorry i just took this part of the code there is a proper next code but it was further down and it didn't get included and i stated that you could assume there was proper declarations for the variables.


but here is the code
it's a bit messy and not commented on yet still testing it to make sure everything works right but if i put in 34 in the power.text field this specific code located about halfway down

vf(cvf) = va(cvf) + vb(cvf)

will come up overflow error while cvf equal 17 and the actual va and vb variables are very huge numbers at this point

Public Class Form1
	Dim tb As String
	Dim tm As String
	Dim a As String
	Dim b As String
	Dim ai As Integer
	Dim bi As Integer
	Dim aih As String
	Dim bih As String
	Dim add As String
	Dim addh As String
	Dim containa As String
	Dim containb As String
	Dim contain As String
	Dim nth As String
	Dim an As String
	Dim bn As String
	Dim ad As Integer
	Dim bd As Integer
	Dim ads As String
	Dim bds As String
	Dim i As Integer
	Dim ii As Integer
	Dim ii2 As Integer
	Dim nr As Integer
	Dim p As Integer
	Dim u As Integer
	Dim d As Integer
	Dim abd As Integer
	Dim abn As Integer
	Dim abdf As Integer
	Dim deno As Integer
	Dim nume As Integer
	Dim rgxExp As New System.Text.RegularExpressions.Regex(" ")
   

	Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button2.Click
		If F_R.Checked = True Then
			nume = Val(numerator.Text)
			deno = Val(denominator.Text)
			For r = nume To 1 Step -1
				If (nume Mod r) + (deno Mod r) = 0 Then
					nume = nume / r
					deno = deno / r
					r = 1
				End If
				numerator.Text = nume
				denominator.Text = deno
			Next
		End If

		'------------------------------------------------------

		If b_e.Checked = True Then
			TextBox6.Text = ""
			added.Text = ""
			term.Text = ""
			Dim x As Integer
			x = Val(power.Text) + 2
			Dim f(x) As String
			Dim va(x) As Integer
			Dim vb(x) As Integer
			Dim vf(x) As Integer
			addh = 0
			If aend.Text <> "" And bend.Text <> "" Then
				nth = 1
				i = 1
				For x = 1 To Val(power.Text)
					i = i * Val(x)
				Next
				For z = 0 To Val(power.Text)
					nr = Val(power.Text) - Val(z)
					ii = 1
					ii2 = 1
					For w = 0 To Val(z)
						ii = ii * Val(w)
						If ii = 0 Then
							ii = 1
						End If
					Next
					For v = 0 To Val(nr)
						ii2 = ii2 * Val(v)
						If ii2 = 0 Then
							ii2 = 1
						End If
					Next
					p = Val(i) / (Val(ii) * Val(ii2))
					For x = 1 To Val(z)
						u = Val(power.Text) - x
						d = x
					Next
					For cv = 1 To (z + 1)
						ai = (Val(power.Text) - (cv - 1)) * Val(apower.Text)
						bi = (cv - 1) * Val(bpower.Text)
						If Val(ai) = 1 Then
							aih = ""
						Else
							aih = "^" + Str(ai)
						End If
						If Val(bi) = 1 Then
							bih = ""
						Else
							bih = "^" + Str(bi)
						End If
						If Val(ai) = 0 Then
							a = ""
						Else
							a = Ae.Text + aih
						End If
						If Val(bi) = 0 Then
							b = ""
						Else
							b = Be.Text + bih
						End If
						abd = Val(aend.Text) ^ ai * Val(bend.Text) ^ bi
					Next
					containa = a
					containb = b
					If abd Mod p = 0 Then
						abn = 1
						abdf = abd / p
					Else
						For r = p To 1 Step -1
							If (abd Mod r) + (p Mod r) = 0 Then
								abn = p / r
								abdf = abd / r
								r = 1
							End If
						Next
					End If
					abn = abn * Val(Aen.Text) ^ bi
					abn = abn * Val(Ben.Text) ^ bi
					If abn < 0 Then
						add = ""
					Else
						add = "+"
					End If
					If z = 0 Then
						TextBox6.Text = TextBox6.Text + Str(abn) + "/" + Str(abdf) + a + b
					Else
						TextBox6.Text = TextBox6.Text + add + Str(abn) + "/" + Str(abdf) + a + b
					End If
					If contains.Checked = False Then
						If Val(nthterm.Text) > 0 Then
							If Val(nthterm.Text) = (z + 1) Then
								term.Text = Str(abn) + "/" + Str(abdf) + a + b
							End If
						End If
						If Val(pt.Text) > 0 Then
							If z = Val(pt.Text) Then
								z = (p + 1)
							End If
						End If
						nth = 0
					Else
						If nth = 1 Then
							contain = containa
							containa = rgxExp.Replace(contain, "")
							If containa = nthterm.Text Then
								term.Text = Str(abn) + "/" + Str(abdf) + a + b
								nth = 0
								nthterm.Text = (z + 1)
								contains.Checked = False
							Else
								contain = containb
								containb = rgxExp.Replace(contain, "")
								If containb = nthterm.Text Then
									term.Text = Str(abn) + "/" + Str(abdf) + a + b
									nth = 0
									nthterm.Text = (z + 1)
									contains.Checked = False
								End If
							End If
						End If
					End If
				Next
				tb = TextBox6.Text
				TextBox6.Text = rgxExp.Replace(tb, "")
				tm = term.Text
				term.Text = rgxExp.Replace(tm, "")

			Else

				If aend.Text = Aen.Text Then
					Aen.Text = 1
					aend.Text = ""
				End If
				If bend.Text = Ben.Text Then
					Ben.Text = 1
					bend.Text = ""
				End If
				ads = ""
				bds = ""
				nth = 1
				p = Val(power.Text)
				vf(1) = Val(Aen.Text)
				vf(2) = Val(Ben.Text)

				For CV = 1 To (p - 1)
					For cva = 0 To (CV + 1)
						vf(0) = 0
						va(cva + 1) = Val(Ben.Text) * vf(cva)
						If Val(pt.Text) > 0 Then
							If cva = Val(pt.Text) Then
								cva = CV + 2
							End If
						End If
					Next
					For cvb = 1 To (CV + 2)
						vf(CV + 2) = 0
						vb(cvb) = Val(Aen.Text) * vf(cvb)
						If Val(pt.Text) > 0 Then
							If cvb = Val(pt.Text) Then
								cvb = CV + 2
							End If
						End If
					Next
					For cvf = 1 To (CV + 2)
						vf(cvf) = va(cvf) + vb(cvf)
						f(cvf) = Str(vf(cvf))
						If Val(pt.Text) > 0 Then
							If cvf = Val(pt.Text) Then
								cvf = CV + 2
							End If
						End If
					Next
				Next
				For cv = 1 To Val(power.Text) + 1
					ai = (Val(power.Text) - (cv - 1)) * Val(apower.Text)
					bi = (cv - 1) * Val(bpower.Text)
					If aend.Text <> "" Then
						ad = Val(aend.Text) ^ ai
						ads = "/" + Str(ad)
					End If
					If bend.Text <> "" Then
						bd = Val(bend.Text) ^ bi
						bds = "/" + Str(bd)
					End If
					a = ads + Ae.Text + "^" + Str(ai)
					b = bds + Be.Text + "^" + Str(bi)
					If Ae.Text = "" Then
						a = ""
						If f(cv) = 1 Then
							a = f(cv)
						End If
					Else
						If ai = 1 Then
							a = Ae.Text
						Else
							If ai = 0 Then
								a = ""
							End If
						End If
					End If
					If Be.Text = "" Then
						b = ""
					Else
						If bi = 1 Then
							b = Be.Text
						Else
							If bi = 0 Then
								b = ""
							End If
						End If
					End If
					If vf(cv) > 0 Then
						If cv > 1 Then
							add = "+"
						Else
							add = ""
						End If
					Else
						add = ""
					End If
					If Be.Text = "" Then
						If cv = p + 1 Then
							add = ""
						Else
							add = "+"
						End If
					End If
					an = f(cv)
					bn = f(cv)
					If aend.Text = "" Then
						If an = 1 Then
							If Be.Text = "" Then
								If cv = 1 Then
									an = ""
								End If
							Else
								an = ""
							End If
						End If
					End If
					If cv = (Val(power.Text) + 1) Then
						If Ae.Text = "" Then
							a = ""
						End If
					End If
					If bend.Text = "" Then
						If bn = 1 Then
							bn = ""
						End If
					End If
					If cv = Val(power.Text) + 1 Then
						If an <> "" Then
							add = "+"
						End If
					End If
					If Ben.Text = 1 Then
						If Be.Text = "" Then

						End If
					End If
					If cv = 1 Then
						TextBox6.Text = TextBox6.Text + an + a + b
					Else
						TextBox6.Text = TextBox6.Text + add + an + a + b
					End If
					If aend.Text = "" And aend.Text = "" Then
						added.Text = Val(added.Text) + vf(cv)
					Else
						added.Text = 0
					End If
					containa = a
					containb = b
					If contains.Checked = False Then
						If Val(nthterm.Text) > 0 Then
							If Val(nthterm.Text) = cv Then
								term.Text = an + a + b
							End If
						End If
						If Val(pt.Text) > 0 Then
							If cv = Val(pt.Text) Then
								cv = (p + 1)
							End If
						End If
						nth = 0
					Else

						If nth = 1 Then
							contain = containa
							containa = rgxExp.Replace(contain, "")
							If containa = nthterm.Text Then
								term.Text = f(cv) + a + b
								nth = 0
								nthterm.Text = cv
							Else
								contain = containb
								containb = rgxExp.Replace(contain, "")
								If containb = nthterm.Text Then
									term.Text = f(cv) + a + b
									nth = 0
									nthterm.Text = cv
								End If
							End If
						End If
					End If
				Next
				If nth = 0 Then
					contains.Checked = False
				End If

				tb = TextBox6.Text
				TextBox6.Text = rgxExp.Replace(tb, "")
				If Val(nthterm.Text) <= p + 1 Then
					tm = term.Text
					term.Text = rgxExp.Replace(tm, "")
				Else
					MsgBox("put in a nth term that is equal to or less then the power of the equation +1")
					TextBox6.Text = ""
					added.Text = ""
					nthterm.Text = 0
				End If
			End If
		End If
	End Sub

[June7]

What is this supposed to do?

For x = 1 To Val(power.Text)
   i = i * Val(x)
   Next

Unless you have previously set the value of i to something, it starts here as 0 and this loop will produce nothing but 0. I didn't look at how you use this result in the following loops because right off this doesn't make sense. Have you step debugged?

Edit: was composing this post just as you posted the expanded code. Now I can see how i value is set. Still suggest step debugging.

This post has been edited by June7: 30 May 2009 - 12:28 AM

[born2c0de]

Here's some tips:

• To ensure that all nCn combinations work:
  Before you calcutate the factorial, check if both paramaters contain the same value. If they do, return 1 or else continue finding the factorial.
  
• Increasing the computable range of numbers:
  Remember that nCr = nC(n-r)
  So if you're supposed to calculate 15C13, convert the expression to 15C2 (since 15 - 13 = 2) and calculate the factorials.
  If you reduce your expressions, the loops will run faster and will also increase your range of computable numbers.

Hope this helps.

[icomeinpieces]

born2c0de, on 30 May, 2009 - 12:17 AM, said:

Here's some tips:

• To ensure that all nCn combinations work:
  Before you calcutate the factorial, check if both paramaters contain the same value. If they do, return 1 or else continue finding the factorial.
  
• Increasing the computable range of numbers:
  Remember that nCr = nC(n-r)
  So if you're supposed to calculate 15C13, convert the expression to 15C2 (since 15 - 13 = 2) and calculate the factorials.
  If you reduce your expressions, the loops will run faster and will also increase your range of computable numbers.

Hope this helps.

hmmm never thought of that it has to compute the numbers down from 15n0 to 15n15 so if i stop it halfway roughly then make it work backwards it should be able to continue to work with numbers nearly double what it can handle right now.


but is there a better way to handle the overflow i mean a calculator program i have can handle much larger numbers that what was coming up in my step debugging before crashing

[Lithium]

Works for me.

[thava]

nearly 25 textboxes and 3 radio buttons it's quite hard to found what you want to do in that 25 textboxes where should i enter the input

[icomeinpieces]

would text boxes be able to handle larger numbers then regular variables?

[born2c0de]

Textboxes stores data as strings and not numbers. Even if a textbox is set to accept only numeric data, it still stores it in a string.

So I'm afraid the answer to your question is No.