widthUnit

default = "res". Unit for the width of the crossbar. Possible values:

• "res": the unit equals the smallest distance between adjacent crossbars along the corresponding axis;

• "identity": a unit of 1 corresponds to a difference of 1 in data space;

• "size": a unit of 1 corresponds to the diameter of a point with size=1;

• "px": the unit is measured in screen pixels.