| 我新调试好的程序如下,应该是对的,供参考 f6 |* j! D) b) B: W/ |+ v3 J' m+ u因为特殊要求,这里的边的长度是二维座标内的空间距离
 , o% {, V- C' `0 H) b4 |
 0 t3 g, c( t( k2 s' w/ yto find-distance
 7 c1 A/ L2 e2 P5 j  let i 0  Y  j, ?# y4 D! v4 Y" |, L1 H  b
 let j 0
 - [$ W# Q: X3 R1 K! V% M% M  let nodedistance 0
 & Y0 d7 A5 p' {2 \. [  let linknumber 0
 ; V9 @3 _' Y$ s/ H8 v0 W& W) Z7 r
 & g( @+ a! s" k/ n* n   while [j < count turtles]6 Y& u; l/ W/ ~! q
 [: x7 ^2 \: N  C; d, |+ [0 D
 while [i < count turtles]" ^1 ]; p: e+ Z* A( @
 [  if link-neighbor? turtle i
 0 H8 c. b8 s- D                        [ask turtle j [set nodedistance nodedistance + distance turtle i]
 ! W* Q* }8 F3 ^1 T* A& O, D, |                          ask turtle j [set linknumber linknumber + count [link-neighbors] of turtle i]- t) d( J) h" X, C% _* J5 l  \
 ]1 Q7 Z+ s6 p. ]
 set i i + 1
 ) j5 Z4 [; h8 a& p        ] 6 f* @( k8 _4 a7 _1 V7 n. i
 set j j + 1
 " ~4 T/ {- }2 M4 R7 P  ]
 3 {: ^4 J8 p$ Z$ D: `3 Z  set average-path-length nodedistance / (linknumber * 2)
 ) o4 T# h- ]( s3 tend
 |