_Factor()

[Paulie]

Returns all the factors of a number greater than 0

The $q parameter can be set to 0 and it will only return how many factors the number has.

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Func _Factor($Num,$q=1)
    If $q = 0 Then
        Local $b=0
        For $a = 1 to $Num
            $result = $Num/$a
            If $result = Round($result,0) Then
                $b+=1
            EndIf
        Next
        Return $b
    Else    
        Local $b=0
        For $a = 1 to $Num
            $result = $Num/$a
            If $result = Round($result,0) Then
                $b+=1
            EndIf
        Next;;
        Local $Factors[$b+1][2],$i=0
        For $a = 1 to $Num
            $result = $Num/$a
            If $result = Round($result,0) Then
                $i+=1
                $Factors[$i][0] = $result
                $Factors[$i][1] = $a
            EndIf
        Next
        $Factors[0][0] = $i
        $Factors[0][1] = $i/2
        Return $Factors
    EndIf
EndFuncoÝ÷ Øw«z+&ÉìZ^jëh×6$int=_Factor(1002,1)
If IsArray($int) Then 
    _ArrayDisplay2($int);modded arraydisplay
Else
    MsgBox(0,"",$int)
EndIf
;-----
Func _ArrayDisplay2(Const ByRef $avArray, $sTitle="")
    Local $iCounter = 0, $sMsg = "", $iCounter2=0
    If (Not IsArray($avArray)) Then
        SetError(1)
        Return 0
    EndIf
    If UBound($avArray,0) = 2 Then
        For $iCounter = 0 To UBound($avArray) - 1
            For $iCounter2 = 0 to UBound($avArray,2)-1
                $sMsg = $sMsg & "[" & $iCounter & "]["&$icounter2&"]    = " & StringStripCR($avArray[$iCounter][$icounter2]) & @CR
            Next
        Next
    ElseIf UBound($avArray,0) = 1 Then
        For $iCounter = 0 To UBound($avArray) - 1
            $sMsg = $sMsg & "[" & $iCounter & "]    = " & StringStripCR($avArray[$iCounter]) & @CR
        Next
    EndIf
    MsgBox(4096, $sTitle, $sMsg)
    SetError(0)
    Return 1
EndFunc

Kinda pointless, but can add to the mathematical capabilities of autoit.

Edited April 4, 2007 by Paulie

[Siddhartha]

lol:

__________________________________________________________________

C:\Program Files\AutoIt3\test.au3(1,20) : ERROR: _Factor(): undefined function.

$int=_Factor(1002,1)

~~~~~~~~~~~~~~~~~~~^

C:\Program Files\AutoIt3\test.au3 - 1 error(s), 0 warning(s)

__________________________________________________________________

would you like to try that math again?

[Paulie]

lol:

__________________________________________________________________

C:\Program Files\AutoIt3\test.au3(1,20) : ERROR: _Factor(): undefined function.

$int=_Factor(1002,1)

~~~~~~~~~~~~~~~~~~~^

C:\Program Files\AutoIt3\test.au3 - 1 error(s), 0 warning(s)

__________________________________________________________________

would you like to try that math again?

Umm... you have to put the function in the same script as the example.

[=sinister=]

lol

[theguy0000]

by the way, instead dividing then rounding then comparing, wouldn't it be easier to just use Mod ( ) ?

If Mod ($Num, $a) = 0 Then $b += 1

[Siddhartha]

Umm... you have to put the function in the same script as the example.

no no no nvm...it was a joke

[Richard Robertson]

Nice. I've wanted to add some UDFs, but never bothered to sit down and find something that hasn't been covered yet.

[Uten]

Did not understand @Paulies function at first. So I wiped up my own. It's quite a bit faster. And demonstrates a different approach. So here it is, if someone comes hunting for something like this..

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func GetFactors($num)
    ; Return an array with all factors of a given number.
    ; NOTE: This function will fail (not return the smallest factors) for 
    ; numbers that is dividable by primes bigger than 997.
    ; To solve that we could increase the prime table or let the function 
    ; calculate the primes needed if it reache a undetermined situation.
    ;SOURCE PRIMES: http://en.wikipedia.org/wiki/List_of_prime_numbers#The_first_500_prime_numbers
    Local $primes = "2 ,3 ,5, 7 ,11 ,13 ,17 ,19 ,23 ,29 ," & _
    "31 ,37 ,41 ,43 ,47 ,53 ,59 ,61 ,67 ,71 ," & _
    "73 ,79 ,83 ,89 ,97 ,101 ,103 ,107 ,109 ,113 ," & _
    "127 ,131 ,137 ,139 ,149 ,151 ,157 ,163 ,167 ,173 ," & _
    "179 ,181 ,191 ,193 ,197 ,199 ,211 ,223 ,227 ,229 ," & _
    "233 ,239 ,241 ,251 ,257 ,263 ,269 ,271 ,277 ,281 ," & _
    "283 ,293 ,307 ,311 ,313 ,317 ,331 ,337 ,347 ,349 ," & _
    "353 ,359 ,367 ,373 ,379 ,383 ,389 ,397 ,401 ,409 ," & _
    "419 ,421 ,431 ,433 ,439 ,443 ,449 ,457 ,461 ,463 ," & _
    "467 ,479 ,487 ,491 ,499 ,503 ,509 ,521 ,523 ,541 ," & _
    "547 ,557 ,563 ,569 ,571 ,577 ,587 ,593 ,599 ,601 ," & _
    "607 ,613 ,617 ,619 ,631 ,641 ,643 ,647 ,653 ,659 ," & _
    "661 ,673 ,677 ,683 ,691 ,701 ,709 ,719 ,727 ,733 ," & _
    "739 ,743 ,751 ,757 ,761 ,769 ,773 ,787 ,797 ,809 ," & _
    "811 ,821 ,823 ,827 ,829 ,839 ,853 ,857 ,859 ,863 ," & _
    "877 ,881 ,883 ,887 ,907 ,911 ,919 ,929 ,937 ,941 ," & _
    "947 ,953 ,967 ,971 ,977 ,983 ,991 ,997"
    $primes = StringSplit($primes, " ,")

    ;Local $primes = StringSplit("2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113",",")
    ; Calculate the factors in $num
    Local $size = 10
    Local $factors[$size]
    $factors[0] = 0
    Local $pos = 1

    While $pos <=$primes[0] AND $num > 1
        If mod($num, $primes[$pos]) = 0 Then 
            $factors[0] += 1
            If $size -1 < $factors[0] Then ReDim $factors[$factors[0] + 10]
            $factors[$factors[0]] = $primes[$pos]
            $num = $num/$primes[$pos]
            ; Do not change $pos as we might want the same prime again!
        Else
            $pos += 1
        EndIf
    WEnd
    If $num > 1 then 
            $factors[0] += 1
            If $size -1 < $factors[0] Then ReDim $factors[$factors[0] + 10]
            $factors[$factors[0]] = $num
    EndIf
    Return $factors
endfunc
func factorsDump(ByRef $a, $head="", $tail= "")
    if $head = "" Then 
        ConsoleWrite("Factors( count:=" & $a[0] & ") : ")
    Else
        ConsoleWrite($head)
    EndIf
    for $i = 1 to $a[0]
        ConsoleWrite($a[$i] & ", ")
    Next
    ConsoleWrite(@CRLF)
EndFunc
;
$a = GetFactors(33765)
factorsDump($a)

[tmo]

what about this one:

Func _primeFactor($iNum)
    Local $aRet[Ceiling(log($iNum)/log(2))]
    Local $a = 0
    Local $i = 2
    If $iNum = 1 Then 
        $aRet[0] = 1
        Return $aRet
    EndIf
    While $iNum > 1
        If Mod($iNum,$i) = 0 Then
            $aRet[$a] = $i
            $a += 1
            $iNum /= $i
        Else
            $i += 1
        EndIf
    WEnd
    Return $aRet
EndFunc

looks more smartly, huh?

[martin]

what about this one:

Func _primeFactor($iNum)
    Local $aRet[Ceiling(log($iNum)/log(2))]
    Local $a = 0
    Local $i = 2
    If $iNum = 1 Then 
        $aRet[0] = 1
        Return $aRet
    EndIf
    While $iNum > 1
        If Mod($iNum,$i) = 0 Then
            $aRet[$a] = $i
            $a += 1
            $iNum /= $i
        Else
            $i += 1
        EndIf
    WEnd
    Return $aRet
EndFunc

looks more smartly, huh?

Yes, but works more dumbly.

[Triblade]

I am trying to use this great function, but I saw 2 times Local $b=0 in here.

One under the If and one under the Else...

Isn't it just as good to put this above the If..Then?

Cause you Local that $b anyway.

Yay, one line less! (If i'm correct...)