MATLAB Central Newsreader - How to assess whether a dataset is generated by a symmetric distribution?

How to assess whether a dataset is generated by a symmetric distribution?

wang wang — Wed, 02 Jul 2008 10:39:02 -0400

I have a dataset and wanna to assess if it is generated by
a symmetric distribution. Except for the usual measure of
the skewness coefficent, is there functions that can give
other measurements of symmetry or do some test for
symmetry? Thanks!

Re: How to assess whether a dataset is generated by a symmetric

Greg Heath — Wed, 02 Jul 2008 14:12:23 -0400

On Jul 2, 6:39=A0am, "wang wang" <pli...@gmail.com> wrote:
> I have a dataset and wanna to assess if it is generated by
> a symmetric distribution. Except for the usual measure of
> the skewness coefficent, is there functions that can give
> other measurements of symmetry or do some test for
> symmetry? Thanks!

You can try a KS test on the two symmetric distributions

p1(x) =3D p(x| x>=3D0) + p(-x| x <0)
p2(x) =3D p(-x| x>=3D0) + p(x| x <0)

Hope this helps,

Greg

Re: How to assess whether a dataset is generated by a symmetric distribution?

Jos — Wed, 02 Jul 2008 14:40:20 -0400

"wang wang" <pligly@gmail.com> wrote in message
<g4fls6$5eo$1@fred.mathworks.com>...
> I have a dataset and wanna to assess if it is generated by
> a symmetric distribution. Except for the usual measure of
> the skewness coefficent, is there functions that can give
> other measurements of symmetry or do some test for
> symmetry? Thanks!

My TRIPLESTEST, a non-parametric for ditributional symmetry
can be found here (beware of line wraps):

http://www.mathworks.com/matlabcentral/fileexchange/loadFile.do?objectId=19547&objectType=FILE

hth
Jos