Weighted Random Number

[Roger Guay]

I want to thank Paul, Peter, Dunbar, Jacques and Scott for helping me with this problem. I now have enough to keep me out of your hair for months!! 

Thanks and cheers,
Roger




On Mar 3, 2013, at 7:27 PM, Paul D. DeRocco <pderocco at ix.netcom.com> wrote:

>> From: Roger Guay
>> 
>> Thanks, Scott. I'm not sure I follow what you're saying, so 
>> let me expand on what I'm trying to do: I want a number (25 
>> to 200) of objects randomly positioned on the stack/window 
>> but favoring the center of the stack/window. Would your 
>> described method do this for me? Sorry for being slow...
> 
> You need to devise a simple mathematical function that translates the range
> of the basic random number generator into the appropriate range, with a
> curve that has a greater slope at the extremes than in the middle.
> 
> First, generate a random number with a reasonably big range, subtract the
> midpoint of the range to get a bipolar value, and then compute a third-order
> polynomial. The zeroth-order coefficient should be the middle pixel value of
> the screen, the second-order coefficient should be zero to make it
> symmetric, the first-order should be small enough that by itself you'd get a
> range that covers only a small portion of the screen, then the third-order
> should be sufficient to cover the full width of the screen. You can fiddle
> the first- and third-order coefficients to adjust the weighting.
> 
> -- 
> 
> Ciao,               Paul D. DeRocco
> Paul                mailto:pderocco at ix.netcom.com 
> 
> 
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