R help - Oct 2011 - alternative option in skewness and kurtosis tests?

I have a question about the D'Agostino skewness test and the Anscombe-Glynn
kurtosis test.


agostino.test(x, alternative = c("two.sided", "less",
"greater"))

anscombe.test(x, alternative = c("two.sided", "less",
"greater"))

The option "alternative" in those two functions seems to be the null
hypothesis. In the output, the statement about the alternative hypothesis is
 correct, which is opposite to what you specify in command. An example
below:


> skewdata
c(rep(44,5),rep(43,15),rep(42,10),rep(41,4),rep(40,3),rep(39,2),rep(38,1))
> agostino.test(skewdata, alternative = "greater")
        D'Agostino skewness test

data:  skewdata

skew = -1.0014, z = -1.7209, p-value = 0.04264

alternative hypothesis: data have negative skewness

> anscombe.test(skewdata,  alternative=“less")
        Anscombe-Glynn kurtosis test

data:  skewdata

kurt = 3.4748, z = 1.0716, p-value = 0.1419

alternative hypothesis: kurtosis is greater than 3


--

	[[alternative HTML version deleted]]

On Oct 25, 2011, at 18:23 , Xiang Gao wrote:
> I have a question about the D'Agostino skewness test and the
Anscombe-Glynn
> kurtosis test.
> 
> 
> agostino.test(x, alternative = c("two.sided", "less",
"greater"))
> 
> anscombe.test(x, alternative = c("two.sided", "less",
"greater"))
> 
> The option "alternative" in those two functions seems to be the
null
> hypothesis. In the output, the statement about the alternative hypothesis
is
> correct, which is opposite to what you specify in command. An example
> below:
Certainly looks like a bug. You should contact the maintainers of the
contributed package containing these tests.

-pd

> 
> 
> 
>> skewdata >
c(rep(44,5),rep(43,15),rep(42,10),rep(41,4),rep(40,3),rep(39,2),rep(38,1))
> 
>> agostino.test(skewdata, alternative = "greater")
> 
>        D'Agostino skewness test
> 
> data:  skewdata
> 
> skew = -1.0014, z = -1.7209, p-value = 0.04264
> 
> alternative hypothesis: data have negative skewness
> 
> 
>> anscombe.test(skewdata,  alternative=?less")
> 
>        Anscombe-Glynn kurtosis test
> 
> data:  skewdata
> 
> kurt = 3.4748, z = 1.0716, p-value = 0.1419
> 
> alternative hypothesis: kurtosis is greater than 3
> 
> 
> --
> 
> 	[[alternative HTML version deleted]]
> 
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-- 
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com