Need help...again---the item with max numer of occurences in array

[darzanmihai]

I would like to get from an 1D array the value that occurs often then the other values of the array....how could I do this, without complicating the script?

Thanks in advance!

[weaponx]

Quick & dirty. This could be optimized depending on how many elements you are dealing with. Unique values only need to be search once but this will search the entire array for every element, even if it has already been searched. A hash table would need to be created to store values that had already been searched.

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Dim $array[10]

$array[0] = "Blue"
$array[1] = "Blue"
$array[2] = "Blue"
$array[3] = "Green"
$array[4] = "Green"
$array[5] = "Green"
$array[6] = "Red"
$array[7] = "Red"
$array[8] = "Red"
$array[9] = "Blue"

MsgBox(0,"Most frequent value", ArrayMode($array))

Func ArrayMode($aArray)
    Local $Numelements = Ubound($aArray)
    
    Local $Highest_Count = 0
    Local $mMode
    
    ;Loop through all elements, totalling up occurences
    For $X = 0 to $Numelements-1
        $Count = 0
        
        For $Y = 0 to $Numelements-1
            If $Array[$Y] = $aArray[$X] Then $Count += 1
        Next
        
        If $Count > $Highest_Count Then
            $Highest_Count = $Count
            $mMode = $aArray[$X]
        EndIf
    Next
    
    Return $mMode
EndFunc

Edited July 23, 2008 by weaponx

[darzanmihai]

Quick & dirty. This could be optimized depending on how many elements you are dealing with. Unique values only need to be search once but this will search the entire array for every element, even if it has already been searched. A hash table would need to be created to store values that had already been searched.

expandcollapse popup

Dim $array[10]

$array[0] = "Blue"
$array[1] = "Blue"
$array[2] = "Blue"
$array[3] = "Green"
$array[4] = "Green"
$array[5] = "Green"
$array[6] = "Red"
$array[7] = "Red"
$array[8] = "Red"
$array[9] = "Blue"

MsgBox(0,"Most frequent value", ArrayMode($array))

Func ArrayMode($aArray)
    Local $Numelements = Ubound($aArray)
    
    Local $Highest_Count = 0
    Local $mMode
    
    ;Loop through all elements, totalling up occurences
    For $X = 0 to $Numelements-1
        $Count = 0
        
        For $Y = 0 to $Numelements-1
            If $Array[$Y] = $aArray[$X] Then $Count += 1
        Next
        
        If $Count > $Highest_Count Then
            $Highest_Count = $Count
            $mMode = $aArray[$X]
        EndIf
    Next
    
    Return $mMode
EndFunc

Thanks Weaponx for both replies

[TerarinKerowyn]

This code doesn't tell you if you have two equal to each other though, only the first occurance is what get it going. If you have 4 Red and 4 Blue with 1 Green should the state say Red / Blue? This doesn't work that way it first looks what the [0] state is. Might it be Blue or Red it will say whatever the [0] state is else if it is green then [1] state is.

[weaponx]

This code doesn't tell you if you have two equal to each other though, only the first occurance is what get it going. If you have 4 Red and 4 Blue with 1 Green should the state say Red / Blue? This doesn't work that way it first looks what the [0] state is. Might it be Blue or Red it will say whatever the [0] state is else if it is green then [1] state is.

That is outside the scope of what was requested. If you needed to know the number of occurrences of every unique value it would have to return a 2-dimensional array with the value in [x][0] and the count in [x][1] (or use a hash table).

Here is how that would look:

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#include <GUIConstantsEx.au3>
#include <Listviewconstants.au3>

Dim $array[10]

$array[0] = "Blue"
$array[1] = "Blue"
$array[2] = "Blue"
$array[3] = "Green"
$array[4] = "Green"
$array[5] = "Green"
$array[6] = "Red"
$array[7] = "Red"
$array[8] = "Red"
$array[9] = "Blue"

GUICreate("Array Value Occurrences", 200)  ; will create a dialog box that when displayed is centered
GUISetState (@SW_SHOW)       ; will display an empty dialog box

$Obj = ArrayGroup($array)

$listview = GUICtrlCreateListView ("Value | Occurrences",10,10,180,380,$LVS_SORTASCENDING)
For $key In $Obj.Keys()
    GUICtrlCreateListViewItem($key & "|" & $Obj.Item($key),$listview)
Next

; Run the GUI until the dialog is closed
While 1
    $msg = GUIGetMsg()
    If $msg = $GUI_EVENT_CLOSE Then ExitLoop
Wend

Func ArrayGroup($aArray)
    Local $oObj = ObjCreate("Scripting.Dictionary")
    Local $Numelements = Ubound($aArray)
   
    For $X = 0 to $Numelements - 1
        $oObj($aArray[$X]) = $oObj($aArray[$X]) + 1
    Next
    Return $oObj
EndFunc

Edited July 25, 2008 by weaponx