Clear Globals();

dlg = Column Dialog(
	yCol = Col List( "Variable",
		Data Type( Numeric ),
		Min Col(1),
		Max Col(2)
	),
	
	Line Up( 2,
		//"Degree of Confidence",	j = Edit Number( .95 ),
		"Number of Samples",	k = Edit Number( 100 )
	),

	V List(
		"Demonstration",
		demo = Radio Buttons( "Test Single Mean", "CompareTwo Means" )
	),

	"", "Select columns for resampling demonstration"
);


If( dlg["Button"] == -1, Throw( "User cancelled" ) );
Remove From( dlg ); Eval List( dlg );

If( demo == 2 & N Items( yCol ) != 2,
	Dialog(
		"Only one column provided to compare two means", "",
		Button( "OK" )
	);
	Throw( "Only one column provided to compare two means" );
);

dt = Current Data Table();
nn = N Row();

// create containers for resampling results.
m = J( k, 1, . );

// get 'population'.
y = dt << Get As Matrix( yCol );

// collect sample statistics.
Choose( demo,
	// test one mean.
	y1 = y[0,1];		// just use the first column.
	For( s = 1, s <= k, s++,
		m[s] = Mean( y1[ J( nn, 1, Random Integer( nn ) ) ] );
	),
	// compare two means.
	y1 = y[0,1];
	y2 = y[0,2];		// just use the first column.
	For( s = 1, s <= k, s++,
		m[s] = Mean( y2[ J( nn, 1, Random Integer( nn ) ) ] ) -
			Mean( y1[ J( nn, 1, Random Integer( nn ) ) ] );
	);
);

// save and show the statistics.
rdt = New Table( "Resample Results",
	New Column( "Sample", Values( 1::k ) ),
	New Column( "Mean", Values( m ) ),
	New Column("Probability"),
	New Column("Quantile")
);

Quantile<<Set Formula(Col Quantile( :Mean,  :Probability));

If( demo == 2,
	Column( 2 ) << Set Name( "Difference" );
);

dist = rdt << Distribution( Y( Column( 2 ) ),
Moments(0) );
dist << Set Title( "Bootstrap Statistics" );