Fig. 1

Scatter plot of a, b tl(q1,q2) and c, d tl(q1,q2,q3). The position of each point is according to a, b [q1,q2] or c, d [q1,q2,q3], and the color coding is according to the function value at each point
Scatter plot of a, b tl(q1,q2) and c, d tl(q1,q2,q3). The position of each point is according to a, b [q1,q2] or c, d [q1,q2,q3], and the color coding is according to the function value at each point