Incidence matrix according to Dynkin symbol

xo ox7/2oo&#x   → height = sqrt[3-1/sin2(2 pi/7)]/2 = 0.583960
(pyramid product of line with {7/2})

o. o.7/2o.    | 2 * ♦ 1  7 0 | 7  7 0 | 7 1
.o .o7/2.o    | * 7 | 0  2 2 | 1  4 1 | 2 2
--------------+-----+--------+--------+----
x. ..   ..    | 2 0 | 1  * * | 7  0 0 | 7 0
oo oo7/2oo&#x | 1 1 | * 14 * | 1  2 0 | 2 1
.. .x   ..    | 0 2 | *  * 7 | 0  2 1 | 1 2
--------------+-----+--------+--------+----
xo ..   ..&#x | 2 1 | 1  2 0 | 7  * * | 2 0
.. ox   ..&#x | 1 2 | 0  2 1 | * 14 * | 1 1
.. .x7/2.o    | 0 7 | 0  0 7 | *  * 1 | 0 2  {7/2}
--------------+-----+--------+--------+----
xo ox   ..&#x ♦ 2 2 | 1  4 1 | 2  2 0 | 7 *
.. ox7/2oo&#x ♦ 1 7 | 0  7 7 | 0  7 1 | * 2