# Contesting for Idiot du Jour

Thomas von Fintel runrev at vonfintel.org
Sat Sep 5 16:19:28 EDT 2020

```I am officially puzzled and out of my waters.

If you divide the circle in four equal parts using two diagonal lines,
you find that 25 percent of all points have a x-value of more than 70
percent of the radius. Using 200 as radius, 25% of all points x > 141,42
(= cos(45°)*200). But using your method only 60/400 = 15% of points have
value x greater than 141,42. So there ecertainly is a bias towards
points in the upper and lower quarter.

I have no idea why this bias isn't influencing your results. Maybe
because the second point is also influenced by this bias. But how?

I wonder whether it's okay to keep this discussion on the list. We are
straying far from matters LiveCode.

Thomas

Am 05.09.2020 um 20:28 schrieb Roger Guay via use-livecode:
> Aha, in prepping my code to send to you, I found an error! Now the Cartesian Coord code is consistent with the Polar Coord code producing a ratio of about ⅓. Here is the code:
>
> on mouseDown
>
> 	getStuff
>
> end mouseDown
>
>
> local tR, tX0, tY0, txl, tX1, tY1, tconstL, tTotCount, tL, tLongCount, tLocA, tLocB
>
>
> on getStuff
>
> 	put item 1 of the loc of grc OuterCircle into tX0
>
> 	put item 2 of the loc of grc OuterCircle into tY0
>
> 	put the width of grc OuterCircle/2 into tR
>
> 	put the left of grc outerCircle into tXl
>
> 	put 2*tR*cos(Pi/6) into tconstL
>
> 	put "" into tTotCount
>
> 	put "" into tLongCount
>
> 	emptyFlds
>
> end getStuff
>
>
> on mouseUp
>
> 	lock screen
>
> 	repeat 10000
>
>
> 		PickApointA
>
> 		PickApointB
>
> 		set the points of grc theChord to tLocA, tLocB
>
> 		GetLength tLocA, tLocB
>
> 	end repeat
>
> 	put tTotCount into fld "totcountFld"
>
> 	put tLongCount/tTotCount into fld "RatioFld"
>
> 	unlock screen
>
> end mouseUp
>
>
> on PickApointA
>
> 	set the numberFormat to "#."
>
> 	put tXl + random(400) into X
>
> 	put sqrt(tR^2 - (X-tX0)^2) - tY0 into y
>
> 	get random(2)
>
> 	if it is 1 then put x, + y+2*tY0 into tLocA
>
> 	else put x, - y into tLocA
>
> end PickApointA
>
>
> on PickApointB
>
> 	set the numberFormat to "#."
>
> 	put tXl + random(400) into X
>
> 	put sqrt(tR^2 - (X-tX0)^2) - tY0 into y
>
> 	get random(2)
>
> 	if it is 1 then put x, + y+2*tY0 into tLocB
>
> 	else put x, - y into tLocB
>
> end PickApointB
>
>
> on GetLength pLocA, pLocB
>
> 	put item 1 of pLocA into PX1
>
> 	put item 2 of pLocA into Py1
>
> 	put item 1 of pLocB into PX2
>
> 	put item 2 of pLocB into Py2
>
> 	set the numberFormat to "#.0"
>
> 	put (pX2- pX1)^2 + (pY2- pY1)^2 into Lsquared
>
> 	put Sqrt(Lsquared) into tL
>
> 	if tL > tconstL then add 1 to tLongCount ---
>
> 	put tLongCount into fld "LongCountFld"
>
> end GetLength
>
>
> Thanks,
> Roger
>
>
>> On Sep 5, 2020, at 11:07 AM, Thomas von Fintel via use-livecode <use-livecode at lists.runrev.com> wrote:
>>
>> „I am known for making many more mistakes than not!“
>> Aren‘t we all?
>> I guess using Cartesian coordinates for choosing points on a circle could produce some bias, though I have no clear idea how.
>> So, what is your code?
>>
>> Thomas
>>
>>> Am 05.09.2020 um 19:15 schrieb Roger Guay via use-livecode <use-livecode at lists.runrev.com>:
>>>
>>> I am known for making many more mistakes than not!
>>
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```