[R] Creating a specific skewed distribution

[Mike Lawrence]

With skewed unimodal distributions, the mode can't equal the mean, so
assuming you want the mean to be around 30, I find that a weibull
function can get close to what you want:

> mean(rweibull(1e5,1.5,33))
[1] 29.77781
> pweibull(60,1.5,33)
[1] 0.9138475

I'm sure you can play with the parameters to try to get even closer to
what you want.

On Wed, Jun 10, 2009 at 2:48 AM, David Arnold<dwarnold45 at suddenlink.net> wrote:
> All,
> Can someone help me create a skewed distribution, mean = 30, with
> probability of selecting a random number from the distribution greater
> than or equal 60 equal to 10%?
>
> I need the probability density function to equal zero at zero, and
> have  a maximum height at or near 30.
>
> Is this possible?
>
> And if it is possible, how can I adjust the distribution so that the
> probability of selecting a random number greater than or equal to 60
> is p.
>
> Thanks. No idea how to start.
>
> David
>
>
>
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>
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-- 
Mike Lawrence
Graduate Student
Department of Psychology
Dalhousie University

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