a simple boxe timer (code included)

[T.Jackson]

One possible "improved" solution is as follows ...

   Select Case b1
      Case Is < 219                                        
         timerN = 3
         timerAc = 120
         timerBc = 60     
      
      Case Is < 243                                         
         timerN = 2
         timerAc = 180
         timerBc = 60

      Case Is <= 255                                         
         timerN = 1
         timerAc = 600
         timerBc = 180 
   End Select

That code will do exactly the same job as ...

    If (b1 <= 255 And b1 >= 243) Then
        timerN = 1
        timerAc = 600
        timerBc = 180
    End If
    If (b1 <= 242 And b1 >= 219) Then
        timerN = 2
        timerAc = 180
        timerBc = 60
    End If
    If (b1 <= 218 And b1 >= 193) Then
        timerN = 3
        timerAc = 120
        timerBc = 60
    End If

BUT, it'll probably compile to half the size, run twice as fast, be more readable, easier to comprehend and definitely far easier to maintain.

Regards,

Trent Jackson

[T.Jackson]

I might add also that the same thing is possible using IF's, select case is always more effcient though however.

      for (int i = 0; i < 12; i++)
      {
          sample = tempArray[i];
          
          if (sample < 0)
             rangeA++;
          else if (sample < 10)
             rangeB++;
          else if (sample < 20)
             rangeC++;
          else if (sample < 30)
             rangeD++;
          else
             rangeE++;
      }

Notice how we start with the smallest number first? Always start with the smallest value first and work downwards with the next biggest value.

Hope it helps

Trent Jackson

[hozone]

i'm new to picbasic.

i didn't know that the "select" statment is so faster and smaller than many "if then" compiled in picbasic [realy i did not look at the select statment ... i've just used the first think i know in picbasic]. it was my mistake that i does't look at the beutiness of my code... even in functions where performance are not needed (like the selection of the time).
i've just share my code.
anyway, thank for suggestions.
any other suggestion will be apriciated.

p.s. is this code more faster? (no IF needed)

LOOKDOWN2 W0,>[255,242,218,192,166,144,124,105,80,59,49,40,0],B0
LOOKUP2 B0,[60,600,180,120,60,60,40,30,20,15,10,45,30],timerAc
LOOKUP2 B0,[60,180,60,60,60,30,40,30,20,15,10,15,15],timerBc
LOOKUP2 B0,[6,1,2,3,4,5,6,7,8,9,10,11,12],timerN

[T.Jackson]

p.s. is this code more faster? (no IF needed)

LOOKDOWN2 W0,>[255,242,218,192,166,144,124,105,80,59,49,40,0],B0
LOOKUP2 B0,[60,600,180,120,60,60,40,30,20,15,10,45,30],timerAc
LOOKUP2 B0,[60,180,60,60,60,30,40,30,20,15,10,15,15],timerBc
LOOKUP2 B0,[6,1,2,3,4,5,6,7,8,9,10,11,12],timerN

At a guess I'm going to say much slower. LOOKUP / DOWN is a function, a group of operations, probably containing many IFs inside it. I think the protocol behind that function would be lengthy, well protected and complex.

I place no bets though, never implemented it.

Trent Jackson

[T.Jackson]

The main reason "Select Case" is faster is because it allows you to structure your code. As with an IF statement there's still a "compare" operation being preformed, but it's usually far better optimized.

The biggest problem with your original code is that every IF will be executed, which consequently wastes time.

Say for example that b1 = 245, the first IF is tested, the result returns true because b1 is within range of (255 - 243), so the block of code associated with that IF is executed, timerN is set to 1 etc ...

Now here's the problem -- all subsequent IFs are executed even though b1 is clearly out of range and the result will always return false while ever b = 245.

    If (b1 <= 255 And b1 >= 243) Then ' Comparison always performed
        timerN = 1
        timerAc = 600
        timerBc = 180
    End If
    If (b1 <= 242 And b1 >= 219) Then ' Comparison always performed
        timerN = 2
        timerAc = 180
        timerBc = 60
    End If

Select Case can be configured in a way so that only one comparison is ever performed, only one block of code is ever executed.

Trent Jackson

[precision]

Great,... Yes.

IF AND THEN --- compile to 159 words.
Select case --- compile to 58 words.

I will have to compere all statements. eg. FOR/NEXT loops. while/Wend, GOTO, GOSUB/RETURN, HI/LOW, TOGGLE.
For time of Execution speed and code space.


.

[T.Jackson]

I will have to compere all statements. eg. FOR/NEXT loops. while/Wend, GOTO, GOSUB/RETURN, HI/LOW, TOGGLE.
For time of Execution speed and code space.

while / wend (same as "do / loop" but without a condition) -- will always be faster than "for next loops" Main reason is because there is no counter, there's no constantly incrementing or decrementing after each iteration.

But I encourage you to conduct your tests and post the results here.

Trent Jackson