Math problem

[Peter M. Brigham, MD]

Well, there's something wrong with the K solution and the Paul solution. Stepping through the script with the debugger, for the first line of tStore, the difference between tEndTime and tStartTime = 7974 (I inserted a temp variable tTemp = tEndTime - tStartTime so I could see what was going on). You want to round upwards to the nearest multiple of 900, which should be 8100. Both the K and Paul solutions give a value of 2.5 -- clearly a really wrong answer. If you amend the Geoff solution as follows:

   --Geoff's itemoffset solution
   put the millisec into tStartClock
   repeat for each line tLine in tStore
      put item 1 of tLine into tStartTime
      put item 2 of tLine into tEndTime
      put item 3 of tLine into tIncrement
      put (x div tIncrement)*tIncrement + item itemOffset((x mod \
             tIncrement > 0),"true,false") of (tIncrement,0) \
             & cr after tStore4
   end repeat

you get 8100, which is correct, and eyeballing the first few lines indicates that Geoff's solution seems to be accurate. 

I fixed the Geoff solution because I understand it. I'm too tired to figure out the errors in the implementation of the other two, sorry.

-- Peter

Peter M. Brigham
pmbrig at gmail.com
http://home.comcast.net/~pmbrig
 
On Feb 17, 2012, at 8:55 PM, Kay C Lan wrote:

> Guys I thought I'd speed test these.
> 
> Unfortunately I don't have the time to figure out exactly how Geoff's
> amended version of Peter's solution actually works in this case; rounding
> 1.1 to 1.25, 3.3 to 3.5. I can get it to work with whole numbers, but not
> 0.25 increments as per the OP.
> 
> The current script produces:
> 
> For 10000 cycles
> K's solution = 25ms
> Paul's solution = 28ms
> Geoff's solution for = 39ms
> Geoff's solution doesn't = K's
> Geoff's solution doesn't = Paul's
> 
> Please amend the script below:
> 
> on mouseUp
>   put 10000 into tRepeats
>   --to create a list of times to use.
>   --900 is used as fixed 1/4 hour interval
>   repeat tRepeats times
>      put 1329494400 & "," & \
>            (1329494400 + random(36000)) & "," & \
>            900 & cr after tStore
>   end repeat
> 
>   --K solution
>   put the millisec into tStartClock
>   repeat for each line tLine in tStore
>      put item 1 of tLine into tStartTime
>      put item 2 of tLine into tEndTime
>      put item 3 of tLine into tIncrement
>      put round(((tEndTime + (tIncrement/2) - 1 -
> tStartTime)/tIncrement),0)/(3600/tIncrement) & cr after tStore2
>   end repeat
>   put the millisec into tEndClock
>   put tEndClock - tStartClock into tTotalTime1
> 
>   --Paul's  max solution
>   put the millisec into tStartClock
>   repeat for each line tLine in tStore
>      put item 1 of tLine into tStartTime
>      put item 2 of tLine into tEndTime
>      put item 3 of tLine into tIncrement
>      put
> round(((tEndTime-tStartTime)/max(tIncrement,60))+0.4999,0)/(3600/max(tIncrement,60))
> & cr after tStore3
>   end repeat
>   put the millisec into tEndClock
>   put tEndClock - tStartClock into tTotalTime2
>   if (tStore2 <> tStore3) then
>      put "Paul's solution doesn't = K's" & cr after tErrors
>   end if
> 
>   --Geoff's itemoffset solution
>   put the millisec into tStartClock
>   repeat for each line tLine in tStore
>      put item 1 of tLine into tStartTime
>      put item 2 of tLine into tEndTime
>      put item 3 of tLine into tIncrement
>      put (tEndTime - tStartTime)/tIncrement into x
>      put 4 into i --tried 900, 4, 25 and 0.25
>      put (x div i*i) + (item itemOffset((x mod i > 0),"true,false") of
> (i,0)) & cr after tStore4
>   end repeat
>   put the millisec into tEndClock
>   put tEndClock - tStartClock into tTotalTime3
>   if (tStore2 <> tStore4) then
>      put "Geoff's solution doesn't = K's" & cr after tErrors
>   end if
>   if (tStore3 <> tStore4) then
>      put "Geoff's solution doesn't = Paul's" & cr after tErrors
>   end if
>   put "For " & tRepeats & " cycles" & cr into msg
>   put "K's solution = " & tTotalTime1 & "ms" & cr after msg
>   put "Paul's solution = " & tTotalTime2 & "ms" & cr after msg
>   put "Geoff's solution for = " & tTotalTime3 & "ms" & cr after msg
>   put tErrors after msg
> end mouseUp
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