YOLO algorithm Grid Cell Coordinates

are bx, by coordinates relative to grid cell coordinates? i.e. 0 - 1 or is it relative to the image?
Does bx, by correspond to center of the object if the center is within the grid cell? or can the part of the object be within the grid cell with center elsewhere?
will the grid cell return bx, by if part of the object is detected, but the center is in another cell? Or does the first element of the prediction pc mean the center of the object is in the cell or center of the object in the cell?

Maybe take a look at this existing thread and let us know if it helps answer your questions…