Re: Re: list of random numbers with given avarage

This could result in values outside the allowed values.

Example:

bottom = 0
top = 100
range = bottom - top = 100
desired average = 25

which would result in

sub f{rand(100) - 50 + 25}

which is equivalent to

sub f{rand(100) - 25}

As you can see, 25% percent of the time, you would get a result that was out of the allowed bounds.

Comment on Re: Re: list of random numbers with given avarage

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Re: Re: Re: list of random numbers with given avarage by belg4mit (Prior) on Mar 12, 2002 at 20:23 UTC
Umm not exactly, I guess I didn't make myself clear. My proposed algorythm does not meet the same requirements, namely top and bottom. It instead provides what I imagine the original algorythm would most likely be used for which is providing "random" values centered around a given value (the average). UPDATE: Note this simpler method makes more sense for the physicists as well. The other algorythm produces many outliers which ought to be discarded in a real data set. Average=50, Range=10 Average: Avg - Rng/2: Avg - Rng/2 + rnd(Rng): 45----50----55 45----50----55 45----50----55 * * ????? ?????? Since rnd can return anything between 0 (minimum) or Range (maximum) we get a full spread. It may also be interesting to note that this is equivalent to `sub f{average+range/2-rnd(range)}` `-- perl -pe "s/\b;([st])/'\1/mg"`	[reply] [d/l]

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Re: Re: Re: list of random numbers with given avarage
by belg4mit (Prior) on Mar 12, 2002 at 20:23 UTC

UPDATE: Note this simpler method makes more sense for the physicists as well. The other algorythm produces many outliers which ought to be discarded in a real data set.

Average=50, Range=10

Average:        Avg - Rng/2:      Avg - Rng/2 + rnd(Rng):
45----50----55  45----50----55    45----50----55
       *         *                 ????? ??????

sub f{average+range/2-rnd(range)}

-- perl -pe "s/\b;([st])/'\1/mg"

[reply]
[d/l]