Comparing strings

[Wicked_Caty]

I've just written a small script that compares two strings and returns the similarity of those two in %. I know of StringCompare, but I want to get a percentage and I also want to get in touch with Autoit.

Compiling doesn't cause any problems, but actually running it does. In line 20 it has a problem with the index and says "Subscript used on non-accessible variable". What's causing that problem, and how can I solve it? Thanks! And sorry for my ugly style

 

Similarity.au3

[Trong]

Try this:
 

#include <MsgBoxConstants.au3>

Global $sTitle = "Similarity"
Global $tTextA = InputBox($sTitle, "Data 1: ")
Global $tTextB = InputBox($sTitle, "Data 2: ")
If $tTextA = $tTextB Then Exit MsgBox($MB_TOPMOST, $sTitle, "Smiler: 100%")
Local $nStringLenTextA = StringLen($tTextA)
Local $nStringLenTextB = StringLen($tTextB)
$tTextA = StringReplace($tTextA, " " & " ", " ")
Local $cSpit = StringInStr($tTextA, " ") ? " " : ""
Local $sSpitA = StringSplit($tTextA, $cSpit)
Local $Smiler = 0, $px = UBound($sSpitA)
For $i = 1 To $px - 1
    If StringInStr($tTextB, $sSpitA[$i]) Then $Smiler += 1
    ConsoleWrite($sSpitA[$i] & " : " & $tTextB & @CRLF)
Next
ConsoleWrite($px & @CRLF)
If $px > 3 Then $px -= 1
Local $SmilerPercent = ($Smiler * 100) / ($px - 1);$nStringLenTextB
If $SmilerPercent > 199 Then $SmilerPercent = 99
MsgBox($MB_TOPMOST, $sTitle, "Smiler: " & $SmilerPercent & "%")

Exit

 

[kylomas]

Wicked_Caty,

$a and $b are NOT arrays.  Try it using stringmid like this...

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#include <MsgBoxConstants.au3>

$title = "Similarity"
;~ $a = InputBox($title, "Data 1")
;~ $b = InputBox($title, "Data 2")
local $a = 'abcd'

local $b = 'abce'

$n = 0
$la = StringLen($a)
$lb = StringLen($b)
$lc = ($la + $lb) / 2

If $la > $lb Then
   $l = $la
ElseIf $lb > $la Then
   $l = $lb

Else
   $l = $lc

EndIf



For $i = 1 To $l
    ConsoleWrite($i & @CRLF)
   If (stringmid($a,$i,1) = stringmid($b,$i,1)) Then
      $n = $n + 1
   EndIf

Next

$p = $n / $l * 100

MsgBox($MB_TOPMOST, $title, $a & @CRLF & $b & @CRLF & $title & ":" & @TAB & $p)

Exit

note: only strings of equal length tested...input supplied as strings, not user input

edit: also your loop should start at position "1" for strings

Edited January 12, 2016 by kylomas
additional info

[JohnOne]

I've just written a small script that compares two strings and returns the similarity of those two in %. I know of StringCompare, but I want to get a percentage and I also want to get in touch with Autoit.

Compiling doesn't cause any problems, but actually running it does. In line 20 it has a problem with the index and says "Subscript used on non-accessible variable". What's causing that problem, and how can I solve it? Thanks! And sorry for my ugly style

 

Similarity.au3

The problem is you're trying to use a variable that is not there.

You can solve it by ensuring you do not try to access a non existent variable.

Edited January 12, 2016 by JohnOne

[kylomas]

Wicked_Caty,

Streamlined the code a bit.  If the string lengths are equal just use one or the other as the length value, no need to add them and divide by two.  I used a ternary expression to replace all of your length determination code...

#include <MsgBoxConstants.au3>

$title = "Similarity"
;~ $a = InputBox($title, "Data 1")
;~ $b = InputBox($title, "Data 2")
local $a = 'abcdf'

local $b = 'abce'



local $len_to_check = (stringlen($a) > stringlen($b)) ? stringlen($a) : stringlen($b), $p = 0, $n = 0

For $i = 1 To $len_to_check
   If (stringmid($a,$i,1) = stringmid($b,$i,1)) Then
      $n = $n + 1
   EndIf

Next

$p = $n / $len_to_check * 100

MsgBox($MB_TOPMOST, $title, $a & @CRLF & $b & @CRLF & $title & ":" & @TAB & $p)

Exit

Good Luck,

kylomas

[jguinch]

I am pretty sure jchd has done something like that with SQLite, but I'm unable to find it

 

[jchd]

jguinch,

I believe you refer to my unifuzz SQLite extension; start reading here, then have luck finding the actual post where the extension resides later in this same thread. The new search feature is terrible. For the matter of string comparison outside of SQLite, this post may give something to work with.

[jguinch]

According to the Levenshtein algorithm (https://en.wikibooks.org/wiki/Algorithm_Implementation/Strings/Levenshtein_distance#VBScript), from the VBS code :

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$s1 = "My String 1"
$s2 = "My String 2 !"



Local $Levenshtein = Levenshtein($s1, $s2)

Local $iMaxLen = StringLen (  StringLen($s1) > StringLen($s2) ? $s1 : $s2 )
Local $percent = Round(($iMaxLen - $Levenshtein) * 100 / $iMaxLen, 2)

ConsoleWrite($percent & "%")


Func levenshtein( $a, $b )
    Local $i, $j, $cost, $d[1], $min1, $min2, $min3

    If StringLen( $a ) = 0 Then Return StringLen( $b )
    If StringLen( $b ) = 0 Then Return StringLen( $a )

    ReDim $d[ StringLen( $a ) + 1][ StringLen( $b ) + 1]

    For $i = 0 To StringLen( $a )
        $d[$i][0] = $i
    Next

    For $j = 0 To StringLen( $b )
        $d[ 0][$j] = $j
    Next

    For $i = 1 To StringLen( $a )
        For $j = 1 To StringLen( $b )
            $cost =  ( StringMid($a, $i, 1) = StringMid($b, $j, 1) ? 0 : 1)

            $min1 = $d[$i - 1][$j] + 1
            $min2 = $d[$i][$j - 1] + 1
            $min3 = $d[$i - 1][$j - 1] + $cost

            If $min1 <= $min2 And $min1 <= $min3 Then
                $d[$i][$j] = $min1
            ElseIf $min2 <= $min1 And $min2 <= $min3 Then
                $d[$i][$j] = $min2
            Else
                $d[$i][$j] = $min3
            EndIf
        Next
    Next

    Return $d[StringLen( $a )][StringLen( $b )]
EndFunc