pathfinding tutorial for a static map

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I'm having trouble with finding a basic tutorial for how to implement a simple path finding algorithm for an already known map that has been built with slam. I've already tried to use this Tutorial Writing A Global Path Planner Plugin but since I don't have no turtle-bot it doesn't work (thought it might be worth a try...). In fact, this and many other tutorials are always about how to set up a robot that navigates to a goal autonomously - isn't that far beyond and much more complex from what I want to achieve? All I need is something like: load map - set point A - set goal B - show path to this point. Is there anywhere a beginner's guide for this or a way to make the mentioned tutorials work without a robot?