[SOLVED] Fuzzy Math
lazarus / 16-Databases

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Slyde · 2022-06-27 19:24

Being the lightweight in the world of Free Pascal and Lazarus that I
am, I find myself at a loss as to why one of these works

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i var i:
integer;// query herei:= previousVec.Size - previousTracker; //
previousVec is a vector, and previousTracker is a
integerDMod1.ZQ_Main.Params.ParamByName('id').AsInteger:=
previousVec[i-1];// subtracting 1 from i works perfectlyand one
doesn't.
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i var i:
integer;// query herei:= (previousVec.Size - previousTracker) - 1;//
should be the same as subtracting 1 from
iDMod1.ZQ_Main.Params.ParamByName('id').AsInteger:= previousVec[i]; //
but this fails
Can someone tell me the difference between the two math problems? 

How is Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i i:=
previousVec.Size - previousTracker;i - 1;
not the same as Code: Pascal  [Select][+][-]window.onload =
function(){var x1 = document.getElementById("main_content_section");
if (x1) { var x = document.getElementsByClassName("geshi");for (var i
= 0; i i:= (previousVec.Size - previousTracker) - 1;

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BobDog · 2022-06-27 22:58

What exactly is i-1
i-=1 is not allowed in pascal.
i:=i-1 is allowed in code, although in a maths exam you would surely
fail
i:=i-1
implies
i-i=-1
i.e.
0=-1

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Thausand · 2022-06-27 23:17

Quote from: BobDog on June 28, 2022, 12:58:52 amWhat exactly is i-1
i is value then subract 1

Quoteimplies
No, it not implies.

question OP is:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i var  i,j,
k: integer; i := previousVec.size - previousTracker;j := i-1; k :=
previousVec.size - previousTracker - 1; .. and why k <> j

make example:
Code: [Select]previousVec.Size := 10;
previousTracker  := 8

i := 10 - 8; (=2)
j := 2 - 1;  (=1)

k := 10 - 8 - 1; (=1)

User slyde say k <> j

Is not logical but can if integer overflow

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Slyde · 2022-06-28 00:26

I didn't mean to confuse anyone.  I posted just the relevant code to
my question, but I'll add to it.

This is the working code:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TForm1.btnPreviousClick(Sender: TObject);var  i: Integer;begin 
btnVerify.Enabled:= False;   DMod1.ZQ_Main.Close; 
DMod1.ZQ_Main.SQL.Text := 'SELECT question, a1, a2, a3, a4, the_answer
' +                              'FROM mult_choice '+                
            'WHERE id = :id';  i:= previousVec.Size - previousTracker;
 // previousVec is a global vector, and previousTracker is a global
integer  DMod1.ZQ_Main.Params.ParamByName('id').AsInteger:=
previousVec[i-1];  DMod1.ZQ_Main.Open;  lblQuestion.Caption:=
DMod1.ZQ_Main.Fields[0].AsString;  rbtn_A1.Caption:=
DMod1.ZQ_Main.Fields[1].AsString;  rbtn_A2.Caption:=
DMod1.ZQ_Main.Fields[2].AsString;  rbtn_A3.Caption:=
DMod1.ZQ_Main.Fields[3].AsString;  rbtn_A4.Caption:=
DMod1.ZQ_Main.Fields[4].AsString;  lblTheAnswer.Caption:=
DMod1.ZQ_Main.Fields[5].AsString;   if i = 1 THEN
btnPrevious.Enabled:= False;   previousTracker:= previousTracker +
1;end;
Please note lines 11 and 12.

Now, here's the code that fails.  Note the changes in lines 11 and 12:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TForm1.btnPreviousClick(Sender: TObject);var  i: Integer;begin 
btnVerify.Enabled:= False;   DMod1.ZQ_Main.Close; 
DMod1.ZQ_Main.SQL.Text := 'SELECT question, a1, a2, a3, a4, the_answer
' +                              'FROM mult_choice '+                
            'WHERE id = :id';  i:= (previousVec.Size -
previousTracker) - 1; 
DMod1.ZQ_Main.Params.ParamByName('id').AsInteger:= previousVec[i]; 
DMod1.ZQ_Main.Open;  lblQuestion.Caption:=
DMod1.ZQ_Main.Fields[0].AsString;  rbtn_A1.Caption:=
DMod1.ZQ_Main.Fields[1].AsString;  rbtn_A2.Caption:=
DMod1.ZQ_Main.Fields[2].AsString;  rbtn_A3.Caption:=
DMod1.ZQ_Main.Fields[3].AsString;  rbtn_A4.Caption:=
DMod1.ZQ_Main.Fields[4].AsString;  lblTheAnswer.Caption:=
DMod1.ZQ_Main.Fields[5].AsString;   if i = 1 THEN
btnPrevious.Enabled:= False;   previousTracker:= previousTracker +
1;end;
In the top block of code, I use Code: Pascal
 [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i  i:=
previousVec.Size - previousTracker;
Then I use the value of i and subtract 1 from it: Code: Pascal
 [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
DMod1.ZQ_Main.Params.ParamByName('id').AsInteger:= previousVec[i-1];
This works perfectly. No issues at all.

However, when I combine the math in the second block of code: Code:
Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i  i:=
(previousVec.Size - previousTracker) - 1;
it should provide me the same outcome as the code in the first block. 
But it fails.  So I was thinking I cld get clarity on this here in the
forum.

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Thausand · 2022-06-28 01:28

Quote from: Slyde on June 28, 2022, 02:26:29 amI didn't mean to
confuse anyone.
It clear 

QuoteHowever, when I combine the math in the second block of code:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i  i:=
(previousVec.Size - previousTracker) - 1;
it should provide me the same outcome as the code in the first block. 
But it fails.  So I was thinking I cld get clarity on this here in the
forum.

It is produce same.
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i program
vectortest; uses  gvector; type  TPreviousVec=specialize
TVector<integer>; var  PreviousVec:TPreviousVec; 
PreviousTracker:integer;  n,i,j:integer;begin 
PreviousVec:=TPreviousVec.Create;   for n:=10 to 20    do
PreviousVec.PushBack(n);   PreviousTracker:=0;   while
previousTracker<PreviousVec.Size do  begin    i:=PreviousVec.Size-
PreviousTracker;    j:=PreviousVec.Size-PreviousTracker-1;   
writeln('previousVec[i-1]= ',previousVec[i-1]:3,'  previousVec[j]=
',previousVec[j]:3,'  (i=',i:3,', i-1=',i-1:3,', j=',j:3,')');   
inc(previousTracker, 1)  end;   PreviousVec.Freeend. 
output:
Code: [Select]previousVec[i-1]=  20  previousVec[j]=  20  (i= 11, i-1=
10, j= 10)
previousVec[i-1]=  19  previousVec[j]=  19  (i= 10, i-1=  9, j=  9)
previousVec[i-1]=  18  previousVec[j]=  18  (i=  9, i-1=  8, j=  8)
previousVec[i-1]=  17  previousVec[j]=  17  (i=  8, i-1=  7, j=  7)
previousVec[i-1]=  16  previousVec[j]=  16  (i=  7, i-1=  6, j=  6)
previousVec[i-1]=  15  previousVec[j]=  15  (i=  6, i-1=  5, j=  5)
previousVec[i-1]=  14  previousVec[j]=  14  (i=  5, i-1=  4, j=  4)
previousVec[i-1]=  13  previousVec[j]=  13  (i=  4, i-1=  3, j=  3)
previousVec[i-1]=  12  previousVec[j]=  12  (i=  3, i-1=  2, j=  2)
previousVec[i-1]=  11  previousVec[j]=  11  (i=  2, i-1=  1, j=  1)
previousVec[i-1]=  10  previousVec[j]=  10  (i=  1, i-1=  0, j=  0)

If not overflow integer then is needed more code. But ... you can make
simple compare and show msg.

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Slyde · 2022-06-28 01:49

That's as good of an explanation as anyone cld ever get.  Thanks,
Thausand.  Thanks for your time.

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Thausand · 2022-06-28 01:50

Quote from: Slyde on June 28, 2022, 02:26:29 am
This is the working code:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TForm1.btnPreviousClick(Sender: TObject);var  i: Integer;begin 
btnVerify.Enabled:= False;   DMod1.ZQ_Main.Close; 
DMod1.ZQ_Main.SQL.Text := 'SELECT question, a1, a2, a3, a4, the_answer
' +                              'FROM mult_choice '+                
            'WHERE id = :id';  i:= previousVec.Size - previousTracker;
 // previousVec is a global vector, and previousTracker is a global
integer  DMod1.ZQ_Main.Params.ParamByName('id').AsInteger:=
previousVec[i-1];  DMod1.ZQ_Main.Open;  lblQuestion.Caption:=
DMod1.ZQ_Main.Fields[0].AsString;  rbtn_A1.Caption:=
DMod1.ZQ_Main.Fields[1].AsString;  rbtn_A2.Caption:=
DMod1.ZQ_Main.Fields[2].AsString;  rbtn_A3.Caption:=
DMod1.ZQ_Main.Fields[3].AsString;  rbtn_A4.Caption:=
DMod1.ZQ_Main.Fields[4].AsString;  lblTheAnswer.Caption:=
DMod1.ZQ_Main.Fields[5].AsString;   if i = 1 THEN
btnPrevious.Enabled:= False;   previousTracker:= previousTracker +
1;end;
Now, here's the code that fails.  Note the changes in lines 11 and 12:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TForm1.btnPreviousClick(Sender: TObject);var  i: Integer;begin 
btnVerify.Enabled:= False;   DMod1.ZQ_Main.Close; 
DMod1.ZQ_Main.SQL.Text := 'SELECT question, a1, a2, a3, a4, the_answer
' +                              'FROM mult_choice '+                
            'WHERE id = :id';  i:= (previousVec.Size -
previousTracker) - 1; 
DMod1.ZQ_Main.Params.ParamByName('id').AsInteger:= previousVec[i]; 
DMod1.ZQ_Main.Open;  lblQuestion.Caption:=
DMod1.ZQ_Main.Fields[0].AsString;  rbtn_A1.Caption:=
DMod1.ZQ_Main.Fields[1].AsString;  rbtn_A2.Caption:=
DMod1.ZQ_Main.Fields[2].AsString;  rbtn_A3.Caption:=
DMod1.ZQ_Main.Fields[3].AsString;  rbtn_A4.Caption:=
DMod1.ZQ_Main.Fields[4].AsString;  lblTheAnswer.Caption:=
DMod1.ZQ_Main.Fields[5].AsString;   if i = 1 THEN
btnPrevious.Enabled:= False;   previousTracker:= previousTracker +
1;end;
look highlight line. If change i then change if

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Slyde · 2022-06-28 02:40

It means the user has seen all previous data.  So I disable the button
at i = 1, the first element of previousVec record.  There's nothing
left to see.  It makes sure the user can't click the button and try to
read an element from the vector that's not there.  And the next click
of the Next button re-enables it.  So far, everything's working out in
my little program.  But I have to say that getting the bugs out of the
previous button click stuff was about as much fun as having a bowl of
rocks for breakfast

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Thausand · 2022-06-28 03:26

Quote from: Slyde on June 28, 2022, 04:40:21 amIt means the user has
seen all previous data. 
Yes, i now that 

QuoteSo I disable the button at i = 1, the first element of
previousVec record.
Yes/No  

In first code answer yes. i=1, vectorindex = i-1 = 0

In second code answer no. i=1 vectorindex = i = 1.

Vector index is run zero ... size-1.

QuoteThere's nothing left to see. It makes sure the user can't click
the button and try to read an element from the vector that's not
there.
If i = 1 then is miss zero vector index that have value.

in both code, it read:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i  
btnPrevious.Enabled := (i=1); 
but if want have good disable button then have show vector index zero
to, is better code:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i  
btnPrevious.Enabled := (i=0); 
But can also make button enable before subtract.

QuoteBut I have to say that getting the bugs out of the previous
button click stuff was about as much fun having a bowl of rocks for
breakfast 
If you have solved problem then good

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Slyde · 2022-06-28 04:28

I'll show you all the code when I finish this.  But it isn't my fault
when you go crazy after seeing it

But yes, it does work as is.  And I understand what you mean, in that
vectors are zero-based.  But what I showed isn't the finished
product.  I don't like how it looks either.  It shld be 0 and not 1. 
But...like I said: I'm a Quotelightweight in the world of Free Pascal
and Lazarus 
But I'll get there.  With a little help from my friends. 

I appreciate your input, Thausand.  I really do.  Constructive words
are always welcome.

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Thausand · 2022-06-28 05:05

Quote from: Slyde on June 28, 2022, 06:28:10 amBut...like I said: I'm
a Quotelightweight in the world of Free Pascal and Lazarus 
But... you eat all that rocks 

QuoteBut I'll get there.
Eat more rocks ?

QuoteI appreciate your input, Thausand.  I really do.  Constructive
words are always welcome.
Thank you for kind words

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Thaddy · 2022-06-28 06:11

Note - according to subject - I already posted a full fuzzy logic unit
a couple of years ago. And based on science, not rumours (or in some
cases above sheer incompetence ill informed or not schooled on the
subject).
See here: https://forum.lazarus.freepascal.org/index.php/topic,41144.m
sg295348.html#msg295348
This is the Zadeh logic which is most common. And the unit is much
simpler........

And before some human starts complaining: this is on topic and a
better way to solve OP's problem.

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Slyde · 2022-06-28 13:37

That's some pretty fuzzy-looking stuff, Thaddy 

Not sure how I'd apply it in my program, but I'll sure study on it. 
Thanks for the offering.