投影片 1

NJ Tree (cont’ 1)

Node 1

r/1

-6.5

Node 1

-10

-7.5

C to Node 1. Original C to A (=7) minus A to Node 1 (=3) plus Original C to B (=9) minus B to Node 1 (=5) all divided by two.

So… C to Node 1 = [(7-3) + (9-5)]/2 = 4.

D to Node 1. Original D to A (=12) minus A to Node 1 (=3) plus Original D to B (=14) minus B to Node 1 (=5) all divided by two.

So… D to Node 1 = [(12-3) + (14-5)]/2 = 9.

D to C = Original D to C minus the sum of the (reduced matrix) r-values divided by two.

11-(15+20)/2 = -6.5

Node 1 to C = Original Node 1 to C [N.B., this value comes from the upper-diagonal]

minus the sum of their (reduced matrix) r-values divided by two.

4 -(15+13)/2 = -10

Node 1 to D = Original Node 1 to D minus the sum of their (reduced matrix) r-values divided by two.

9 -(20+13)/2 = -7.5

C to Node 2 = (Original C to Node 1)/2 plus (C's r/1 minus Node 1's r/1)/2.

4/2 + (15-13)/2 = 3

C to Node 2 = 3

Node 1 to Node 2 = (Original C to Node 1) minus distance just computed for C to Node 2.

4 - 3 = 1

Node 1 to Node 2 = 1

Alternative starting with Node 1 to Node 2. What do we know about Node 1 to Node 2? We know something that INCLUDES it, which is C to Node 1 (= C to Node 2, which we don't want, plus Node 2 to Node 1, which we do want).

Node 1 to Node 2 = (C to Node 1)/2 plus (Node 1's r/1 - C's r/1)