I fear, some auxiliary columns are necessary to make it work.
But one can "store" them together with the report - as transform columns:
Open( "$SAMPLE_DATA/Functional Data/Weekly Weather Data.jmp" );
Graph Builder(
Transform Column(
"week20",
Formula( Col Quantile( If( :Week of Year == 20, :TAVG, . ), 0.5, :STATION ) )
),
Transform Column(
"week1",
Formula( Col Quantile( If( :Week of Year == 1, :TAVG, . ), 0.5, :STATION ) )
),
Variables( X( :week1 ), Y( :week20 ) ),
Elements( Points( X, Y, Legend( 3 ) ), Smoother( X, Y, Legend( 4 ) ) )
);