# RE: st:normal linear (mis)scaling

 From "Nick Cox" To Subject RE: st:normal linear (mis)scaling Date Thu, 5 Aug 2004 15:57:27 +0100

```. help mathfun

indicates some functions with bounded range.
Then use some linear re-expression to suit.

2 * invlogit(x) - 1

maps to (-1,1). Now tell me that it _really_
has to be [-1,1] not (-1,1)....

Nick
n.j.cox@durham.ac.uk

> -----Original Message-----
> From: owner-statalist@hsphsun2.harvard.edu
> [mailto:owner-statalist@hsphsun2.harvard.edu]On Behalf Of
> D.Christodoulou
> Sent: 05 August 2004 14:23
> To: statalist@hsphsun2.harvard.edu
> Subject: Re: st:normal linear (mis)scaling
>
>
> Nick,
>
> thanks for your reply. In the same sense I can use:
> - histogram normal if normal >= -0.2 | normal <=-0.8 -
> to remove the exact bit that I want.
>
> However, it is essential for this distribution to have bounds in the
> interval [-1,1].
> How to I restrict the random observations to be generated into this
> interval.
>
> thanks again,
> Dimitris
>
> Nick Cox wrote:
> >
> > I would generate lots of values from a Gaussian
> > and then take a big bite out of it, with some
> > randomness about the biting.
> >
> > . set obs 1000
> > . gen normal = invnorm(uniform())
> > . qnorm normal
> > . histogram normal if (abs(normal) * uniform()) > 0.5
> > . histogram normal if (abs(normal) * uniform()) > 0.6
> >
> > Nick
> > n.j.cox@durham.ac.uk
> >
> > D.Christodoulou
> > >

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