Figure 4

Overview of the various lengths, angles and points. A: The angle Θ defines the direction of a straight line y (x, Θ) through C₉₀. The angle ϕ _i (Θ) originates at C₉₀ and is defined as the smallest angle between the line r _i from C₉₀ to the pixel P _i and y (x, Θ). Aa and Ab illustrate the relation for P _i located at opposite sides of C₉₀. s _i (ϕ) is defined as the arc of the circle with radius r _i from y (x; Θ) to P _i . B: The dimensions of the translated and rotated scan data based on the distances (dotted lines) of the vertices of the original scan to the straight lines through C₉₀ in and perpendicular to the heading direction of the cell (straight lines). Note the increase in basal area caused by the rotation (see also Figure 11 and Figure 12).