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FUNCTION: Acuratime() ;Keeps precise time to .0001 seconds

 
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philz



Joined: 05 Jun 2007
Posts: 87
Location: USA
PostPosted: Wed Dec 12, 2007 10:35 am    Post subject: FUNCTION: Acuratime() ;Keeps precise time to .0001 seconds Reply with quote
I was looking for a way to keep accurate, precise time in terms of AHK's YYYYMMDD24-HRMISS format and extending it to YYYYMMDD24-HRMISSMILISEC (which includes a decimal for tenths of miliseconds)

I have thought of three methods, each with different good and bad things.

Here is the code for the first method:
It uses urldownloadtovar() which can be found here.
Code:

acuratime()
{
   x := urldownloadtovar("http://132.163.4.101:14")
   secmilla := substr(x,33,6) = 1000 ? SubStr(x,23,2)+1 "0000.0" : SubStr(x,23,2) "0" substr(x,33,6)
   timestring := A_YYYY substr(x,11,2) substr(x,14,2) substr(x,17,2) SubStr(x,20,2) secmilla
   return,  %timestring%
}

This is precise to one tenth of a milisecond. The problem is that It will lag because of the need to download from a time server, so accuracy is an issue.

Here is the code for the second method:
Code:
SetWorkingDir, %a_scriptdir%

loop {
FileAppend, % precisetime() "`n",dump.txt
SplashTextOn,  520, 40, It is now, % precisetime()
}
;use this to test it.

precisetime()
{
;the logic behind this is that the last three digits of a_tickcount will
;have a certain value when the second of a_now changes. So by determining
;this value, we can use it alongside a_tickcount to determine miliseconds
;that fit out own nice timestamp.
   static offset
   startcount := A_tickcount
   starttime := A_now
   IF(offset = "") ;determine the value of offset
      loop
      {
         if( a_now - starttime > 0) {
            offset := substr(a_tickcount - startcount, -2)
            break
         }
      }
   if( substr(a_tickcount, -2) - offset < 0) {
      if( strlen(substr(a_tickcount,-2) + 1000 - offset)<4) {
         Loop, % 4 - strlen(substr(a_tickcount,-2) + 1000 - offset)
            milisec := "0" substr(a_tickcount,-2) + 1000 - offset
      }
      else milisec := substr(a_tickcount,-2) + 1000 - offset
   }
   else if( strlen(substr(a_tickcount,-2)- offset)<4) {
         Loop, % 4 - strlen(substr(a_tickcount,-2)- offset)
            milisec := "0" substr(a_tickcount,-2) - offset
   }
   Time := a_now milisec
   return, %time%
}

This has two issues.
One is that sometimes the milisecond part doesn't always turn out to be four digits long. I don't know why.
The other issue is that sometimes the miliseconds revert to zero when they should not. This makes times inaccurate to no more than one half of a second.

While posting I came up with a third Idea:
Code:

precisetime()
{
return, % a_now "0" substr(a_tickcount -140,-2) ;I subtract 140 to bring accuracy but it doesn't always work
}
;this one seems to work best because I noticed that an a_tickcount
;second changes almost perfectly in line with with a_now.

It is the simplest but the seconds revert in the wrong place sometimes.

Any Ideas on fixes????

I decided to put this into the Scripts & Functions forum because the acuratime works fine except for the lag in downloading from a time server. If you guys have qualms about my placement of the post It will be moved.
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BoBoĻ
Guest
PostPosted: Wed Dec 12, 2007 2:03 pm    Post subject: Reply with quote
[Brainfart]wouldn't it be possible to adjust the detected timestamp with getting&adding the time the download itself has needed? [/Brainfart]
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philz



Joined: 05 Jun 2007
Posts: 87
Location: USA
PostPosted: Wed Dec 12, 2007 8:03 pm    Post subject: Reply with quote
BoBoĻ wrote:
[Brainfart]wouldn't it be possible to adjust the detected timestamp with getting&adding the time the download itself has needed? [/Brainfart]


Are you suggesting I determine the download time via taking a_tickcount before and after then adding the difference to the time? It may add some accuracy. I still think there must be a better way to do this though.
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philz



Joined: 05 Jun 2007
Posts: 87
Location: USA
PostPosted: Thu Dec 13, 2007 6:36 pm    Post subject: Reply with quote
looks like the internet download method won't work anyway.
The time server doesn't include miliseconds.

Yhis seems to be the most accurate method. I cannot make autohotkey reach perfection on this. This is as good as I can get it.

Code:
precisetime()
{
   static offset, timecalled = 1
   if %Timecalled%
   {
      timecalled = 0
      starttime := A_now
      loop {
         if( A_now - starttime) {
            offset := a_tickcount - 5
            offset := substr(offset,-3)
            break
         }
      }
   }
   return, % a_now substr(a_tickcount - offset,-2)
}
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