It's not clear what you are saying. Do you mean you want to use the Analyze Permissions feature for a guest? If so, there is no need to do this. You simply need to look at Unregistered / Unconfirmed user group permissions (and you can also look at the node permissions for each node for Unregistered / Unconfirmed if necessary.
The Analyze permissions feature is generally of use for registered users because typically, when a site has been set up in the correct way, users are in multiple user groups. Analyze permissions looks at the combination of all user group permissions for a user and outputs that. It therefore isn't really needed for Guests (or indeed users that may solely be in the Registered user group).