How to make robot localise itself its initial point with existing map

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If you use amcl for localization, there is a service called global_localization that will disperse the particles ramdomly at startup (oposed to giving amcl an initialpose). However as far as I know, you then have to move around with the robot for some time for the particles to "align"/localize. From that point on you can give a goal to move_base and it will navigate there. Possibly you will have to order the first movements via some other node, as move_base will possibly get into trouble with ever changing localization at this point, or amcl will not even publish a localization until some quality parameter is fullfiled. There is also a way to give a initialpose to amcl that practically includes the hole map, might be worth a try as well.