def set_vertex(idfObj, vertexNum: int, x: float=0, y: float=0, z: float=0):
    """Sets a single vertex of the passed idfObject (idfObj)
     to the specified x,y and z coordinates."""
    for val, name in zip((x, y, z), 'XYZ'):
        idfObj['Vertex_{}_{}coordinate'.format(vertexNum, name)] = round(val, 2
            )
