This function finds the coordinates of the points establishing the four divisions of the hull
quadBorders(pointsDF, xInt, yInt, vCoords, hCoords)A data frame with 2 columns representing the 12 points (not unique) determining the boundaries of the hull divisions.
A data frame with the x and y coordinates of the points.
The coordinate where the vertical line intersects the x axis.
The coordinate where the horizontal line intersects the y axis.
The y coordinates of the two points where the vertical line intersects the convex hull.
The x coordinates of the two points where the horizontal line intersects the convex hull.