You can specify the title (shown in the title bar of a platform’s report) by adding the title command to the launch request. The following example replaces the standard bivariate report’s title with a user-specified one (My Title).
dt = Open( "$SAMPLE_DATA/Big Class.jmp" );
dt << Bivariate( x( :height ), y( :weight ), Title( "My Title" ) );

Help created on 7/12/2018