continued fractions

[Volker Vanoni]

Hi,
I am looking for help again. Here is my code:
#COMPILE EXE
#DIM ALL

FUNCTION PBMAIN () AS LONG
DIM arr(18) AS LONG
DIM i AS LONG
solution(SQR(7),arr())
FOR i = 0 TO 17
PRINT STR$(arr(i))+" ";
NEXT i

WAITKEY$

END FUNCTION

FUNCTION solution(x AS DOUBLE,arr() AS LONG)AS LONG

DIM k AS LONG, a AS LONG
DIM y AS DOUBLE
FOR k = 0 TO 17
a = INT(x)
arr(k) = a
y = x - a
IF y = 0 THEN
GOSUB endit
ELSE
x = 1/y
END IF
NEXT k
endit:
END FUNCTION
The result is correct but the time is not! Has anyone an idea to make it faster?
kind regards
Volker

[Paul Dixon]

Volker,
your program runs in under 2 microseconds. How fast do you want it?

Some suggestions:
Change:
DIM y AS DOUBLE
to
REGISTER y AS EXT

Don't use
GOSUB endit
instead use
EXIT FUNCTION

Paul.

[Michael Mattias]

>your program runs in under 2 microseconds.

I was afraid to try it myself, for fear I would become far less diplomatic than "How fast do you want it?"

BTW, the "exit function" thing? That should be a command, not a suggestion. GOSUB should NEVER be used without a paired RETURN.



MCM

[Chris Holbrook]

GOSUB should NEVER be used without a paired RETURN.

I think it is a matter of personal - or possibly corporate - taste. It has to be better programming practice to have a matching RETURN. ISTR Mr Zale commenting that at RETURN in a GOSUB is OK, so presumably the stack gets cleaned up correctly when you EXIT or END from a SUB or FUNCTION, irrespective of any GOSUB nesting, intended or otherwise.

In the context given, the GOSUB does not appear to add any value at all.

[Volker Vanoni]

Re: continued fractions

I am very sorry but my time is over 23 seconds. I would not have bothered you otherwise. Maybe it' s Vista !
kind regards
Volker

[Paul Dixon]

Volker,
are you sure you have posted the correct code?

The answer I get is:

2 1 1 1 4 1 1 1 4 1 1 1 4 1 1 1 4 1

and it takes 1.5usecs to run here.

If the same code is taking 23 seconds for you then there is a big problem somewhere.

Paul.

[Michael Mattias]

> In the context given, the GOSUB does not appear to add any value at all.

It's clearly the wrong choice - in context.

However, not coding a RETURN when you code a GOSUB is totally and absolutely unforgiveable, especially when dealing with a 'newbie,' and super-especially coming from someone who has been writing in BASIC as long as have you.

Assuming the compiler is always going to be your momma and clean up after you is a very, very, very bad habit to acquire.

[Mel Bishop]

...code is taking 23 seconds...there is a big problem...

Agreed. Bring up Task Manager and see if something is there, chewing up CPU usage.

[Chris Holbrook]

...totally and absolutely unforgiveable, especially when dealing with a 'newbie,' and super-especially coming from someone who has been writing in BASIC as long as have you.

Unworthy comment. Read and consider my post. Take your medication. Preferably, don't reply.

[Dale Yarker]

#compile exe
#dim all

function solution(x as double,arr() as long)as long
  dim k as long, a as long
  dim y as double
  for k = 0 to 17
    a = int(x)
    arr(k) = a
    y = x - a
    if y = 0 then
      exit function
    else
      x = 1/y
    end if
  next k
end function

function pbmain () as long
  dim arr(18) as long
  dim i as long
  local T_Start, T_Stop as double
  T_Start = timer
  solution(sqr(7),arr())
  for i = 0 to 17
    print str$(arr(i))+" ";
  next i
  'sleep 100  'keep coming up 0 seconds on my PC
              'temporarily added sleep to check my code
  T_Stop = timer
  print : print str$(T_Stop - T_Start)

  waitkey$

end function

Mod'd code to get run time. I get zero seconds using Timer.

Also fixed the gosub without return. Could have replaced gosub with goto, but goto starts arguements.

Cheers,

[Michael Mattias]

>Could have replaced gosub with goto, but goto starts arguements

Hmm, that happens in COBOL newsgroups, too, when code using GO TO is posted.

But nearly as big an argument as you can provoke by suggesting various uses of the full stop (the period, ".").

Thank goodness the comma (",") in COBOL is always optional and always 'documentary only!'

[Volker Vanoni]

continued fractions

Thank you all.
I solved my time problem using another anti-virus-program.
Why are you so upset because used "goto". This is obviously possible and yields a correct result. "exit for" and "exit return" do here the same.
Kind regards
Volker