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Re: st: lnskew0 and bcskew0

From   "Austin Nichols" <>
Subject   Re: st: lnskew0 and bcskew0
Date   Thu, 19 Apr 2007 15:22:54 -0400 --
The histogram may "be skewed" to your eye, but I'm betting the
skewness is very very close to zero.
sysuse auto, clear
qui su mpg, d
di r(skewness)
lnskew0 z=mpg
qui su z, d
di r(skewness)

I suppose the "right" method depends on the desired result--here is
another way to transform your variable to make its skewness zero (and
its mean zero, and its standard deviation one):
sysuse auto, clear
sort mpg
g z=invnorm(_n/(_N+1))

On 4/19/07, <> wrote:
How certain can I be that lnskew0 and bcskew0 have normalized the
distribution for the variable have transformed with them (a percent)?
After using these transformations, the histograms are still skewed.
What could be the problem? Is it possible that they don't work in all
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