Use the Hide, Exclude, and Label messages to hide, exclude, and label rows. These messages are toggles, meaning that to turn the messages on you send them once, and to turn them off you send the message a second time. They also accept Boolean arguments to explicitly turn them off and on.
For example, to hide all rows in Big Class where age is greater than 13, you could do the following:
dt = Open( "$SAMPLE_DATA/Big Class.jmp" );
dt << Select Where( :age > 13 );
dt << Hide( 1 );
dt = Open( "$SAMPLE_DATA/Big Class.jmp" );
dt << Select Where( :age > 13 ) << Hide( 1 );

Help created on 10/11/2018