topic Re: Summary table ignoring weight column in specific conditions (bug?) in Discussions

Summary table ignoring weight column in specific conditions (bug?)

FN — Fri, 09 Jun 2023 19:58:30 GMT

For some reason, when adding to summary a Median(), it ignores the weights provided for other statistics.

Here, I am creating a simple filter where every male row has 0 weight, hence max and min for males should not exist.

Names Default To Here( 1 );
dt = Open( "$SAMPLE_DATA/Big Class.jmp" );


// New column: Filter
dt << New Column( "Filter",
	Numeric,
	"Continuous",
	Format( "Best", 12 ),
	Formula( :sex != "M" )
);

list_columns_to_group = {"height", "weight"};


// Ignores weights for max, min...
dt << Summary( Group( :Sex ),
 Mean(list_columns_to_group),
 Max( list_columns_to_group ),
 Min(list_columns_to_group ),
 Median(list_columns_to_group),
 Weight(:Filter));


// Works as expected
dt << Summary( Group( :Sex ),
 Mean(list_columns_to_group),
 Max( list_columns_to_group ),
 Min(list_columns_to_group ),
 //Median(list_columns_to_group),
 Weight(:Filter));

Re: Summary table ignoring weight column in specific conditions (bug?)

Mark_Bailey — Mon, 04 Oct 2021 20:01:33 GMT

I'm just guessing, but does it make sense to apply a weight to a quantile or the cumulative distribution function?

It makes sense with moments, but maybe not with the CDF.

Re: Summary table ignoring weight column in specific conditions (bug?)

FN — Tue, 05 Oct 2021 06:20:15 GMT

I have updated the description as the main issue I found is that it ignores the weights for other statistics.

About weight median, this is a topic by itself :)

https://en.wikipedia.org/wiki/Weighted_median