Keyword Density

can you explain this a little more? I'm unfamiliar with the term

Do you mean how many times ALL words appear in a file, or how many times a word you supply appears in a file?

The measure of how many times a word is repeated compared to the overall content. For example, if a word was listed 5 times out of a word count of 100, the keyword density for that word is 5%.

I want the keyword density for all words in a text file, sorted by highest density descending.

Thanks

And here's another one ;)

2 memos and a button on a form, paste some text into Memo1 and press the button
The function Explode() is taken from here:
http://www.swissdelphicenter.ch/torry/showcode.php?id=1326



unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TExplodeArray = array of String;

type
  TWordRec=Record
    S:String;
    Count:Integer;
  end;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Memo1: TMemo;
    Memo2: TMemo;
    procedure Button1Click(Sender: TObject);
  private
    WArray: array of TWordRec;
    procedure WordOccurence(Text: string);
    procedure SortWA;
  public
  end;
var
  Form1: TForm1;
  function Explode(const cSeparator, vString: String): TExplodeArray;
implementation

{$R *.dfm}


function Explode(const cSeparator, vString: String): TExplodeArray;
var
  i: Integer;
  S: String;
begin
  S := vString;
  SetLength(Result, 0);
  i := 0;
  while Pos(cSeparator, S) > 0 do begin
    SetLength(Result, Length(Result) +1);
    Result[i] := Copy(S, 1, Pos(cSeparator, S) -1);
    Inc(i);
    S := Copy(S, Pos(cSeparator, S) + Length(cSeparator), Length(S));
  end;
  SetLength(Result, Length(Result) +1);
  Result[i] := Copy(S, 1, Length(S));
end;


procedure TForm1.WordOccurence(Text: string);
var
  i,j:Integer;
  TextWordList: TExplodeArray;
  AlreadyThere:Boolean;
  tempS:String;
begin
  TextWordList := Explode(' ', Text);
  for i := 0 to Length(TextWordList)-1 do begin
    AlreadyThere:=False;
    tempS:=Trim(TextWordList[i]);
    //tempS:=UpperCase(tempS);      //only if no case sensitivity required
    if not (tempS[Length(tempS)] in ['a'..'z','A'..'Z']) then
      Delete(tempS,Length(tempS),1);

    if length(tempS)>1 then
       if not (tempS[1] in ['a'..'z','A'..'Z']) then
          Delete(tempS,1,1);

    if Length(WArray)>0 then begin
      for j := 0 to Length(WArray)-1 do begin
        if WArray[j].S = tempS then begin
          inc(WArray[j].Count);
          AlreadyThere:=True;
        end;
      end;
    end;
    if not AlreadyThere then begin
      SetLength(WArray,Length(WArray)+1);
      WArray[High(WArray)].S:=tempS;
      WArray[High(WArray)].Count:=1;
    end;
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
i:Integer;
begin
 Memo2.Clear;
 WordOccurence(Memo1.Text);
 SortWA;
 for i:=0 to Length(Warray)-1 do begin
   Memo2.Lines.Add(Warray[i].S+' = '+IntToStr(Warray[i].Count));
 end;
 SetLength(WArray,0);
end;


procedure TForm1.SortWA;
var
 ok: boolean;
 i, n: integer;
 temp: TWordRec;
begin
 n := Length(WArray);
 repeat
   ok := true;
   for i := 0 to n - 2 do
     if WArray[i].Count < WArray[i+1].Count then begin
       temp := WArray[i];
       WArray[i] := WArray[i+1];
       WArray[i+1] := temp;
       ok := false;
     end;
 until ok;
end;


end.

BTW, as you probably don't care about case sensitivity, it would be probably better to re-activate this line in the WordOccurence procedure (delete the first "//")
//tempS:=UpperCase(tempS);      //only if no case sensitivity required

and replace this
Memo2.Lines.Add(Warray[i].S+' = '+IntToStr(Warray[i].Count));
with this (in the Button1's OnClick)
Memo2.Lines.Add(LowerCase(Warray[i].S)+' = '+IntToStr(Warray[i].Count));

Thanks Pierre, thats an awesome example.

TName, yours didnt work

Glad to help

>TName, yours didnt work

Would you mind specifying?
Just curious, as I've re-copied the code as it is into delphi and ran it without problems.

I can't remember. Let me copy it back into delphi and I'll let you know just now

Input:

dog
dog
cat cat
cow
moo
horse

output:

dog
dog
cat = 1
cat
cow
moo
horse = 1

----------------------------------------------------------------------------------------------------

What I was looking for was

dog 2, 28%
cat 2, 28%
cow, 1, 14%
moo, 1, 14%
horse, 1, 14%


:)

You're right, I somehow forgot about the %...