... GPI Data Pipeline 1.0 documentation . GPItv Viewer User?s Guide . ... Starting GPItv . ... GPItv can be started from a script or from the IDL command-line prompt. ... If starting from within a script, you may wish to specify the ?/block? option to pause the script while the user works with GPItv, or else use Multi-Session mode to allow concurrent execution. ... In addition to menu functions and mouse modes described below, GPItv has several functions directly available from the main window: . ...