The Concatenate message combines rows of several data tables top to bottom, vertically joining the rows.
dt << Concatenate( DataTableReferences,...,Keep Formulas,
Output Table Name( "name" ) );
For example, if you have subsetted tables for males and females, you can put them back together using Concatenate:
dt = Open( "$SAMPLE_DATA/Big Class.jmp" );
dt << Select Where( :sex == "M" );
m = dt << Subset( Output Table Name( "M" ) );
dt << Invert Row Selection;
f = dt << Subset( Output Table Name( "F" ) );
both = m << Concatenate( f, Output Table Name( "Both" ) );
Or, instead of creating a new table containing all the concatenated data, you can append all the data to the current data table:
dt = Open( "$SAMPLE_DATA/Big Class.jmp" );
dt << Select Where( :sex == "M" );
m = dt << Subset( Output Table Name( "M" ) );
dt << Invert Row Selection;
f = dt << Subset( Output Table Name( "F" ) );
both = dt << Concatenate( m, f, "Append to First Table" );