topic Re: How do I check the kind of distribution of a sample data? in Discussions

How do I check the kind of distribution of a sample data?

RogerBui — Wed, 28 Dec 2016 13:57:59 GMT

Hi everybody,

Could you please have me a clue to check a kind of distribution of a sample data set by JSL (Ex: check to see if a sample data has normal distribution or not?

Thanks.

Re: How do I check the kind of distribution of a sample data?

txnelson — Wed, 28 Dec 2016 14:10:05 GMT

Here is the example from:

Help==>Scripting Index==>Distribution==>Continuous Distribution==>All

Names Default To Here( 1 );
dt = Open( "$SAMPLE_DATA/Cities.jmp" );
obj = Distribution( Column( :CO ) );
obj << Fit Distribution( All( 1 ) );

Re: How do I check the kind of distribution of a sample data?

Mark_Bailey — Wed, 28 Dec 2016 14:14:51 GMT

I assume by your question that the user is not directly involved (interactive assessment) but instead a hypothesis test is desired. I would employ the Distribution platform. Launch it with the data column to be tested in the Y role. Fit the normal distribution and obtain the results of the goodness of fit test. Illustrated with the weight variable in the sample data table Big Class:

dt = Open( "$SAMPLE_DATA/Big Class.jmp" );

dist = dt << Distribution(
	Y( :weight ),
	Fit Distribution( Normal( Goodness of Fit( 1 ) ) )
);

dist rep = dist << Report;

p value = dist rep["Goodness-of-Fit Test"][NumberColBox("Prob<W")] << Get( 1 );

Hope answer helps.