|
|
新手,在看netlogo自带的例子时,有几行程序看不懂,希望高手能够指点。
W, ~/ [' t: F/ n5 P @netlogo自带的social science--traffic grid这一例子当中,
, M* C2 ?* {1 wglobals
$ ^0 _4 `) i" K9 G[6 a0 }) X! ?* c
grid-x-inc ;; the amount of patches in between two roads in the x direction' l! m# O4 w. ^- h1 `2 p) t. C9 z) ^
grid-y-inc ;; the amount of patches in between two roads in the y direction
7 i9 c3 k' i: q" _5 q acceleration ;; the constant that controls how much a car speeds up or slows down by if3 b8 G6 h. m$ X9 D9 J
;; it is to accelerate or decelerate: o* Q* f Y8 P$ \; I5 J5 H" [5 F3 F
phase ;; keeps track of the phase1 U4 A6 G0 s' P5 ]
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
5 a' `& M5 D9 U2 [6 B: ]- f current-light ;; the currently selected light J" D7 \' {3 ~ U2 M4 O
8 u$ }- P7 B1 @' g" b' |
;; patch agentsets% H3 R$ A# h$ j9 W
intersections ;; agentset containing the patches that are intersections/ O: X) [( L6 S
roads ;; agentset containing the patches that are roads/ l: @4 F' ]+ u: ~' \
]
# t- U2 U. e) A/ l5 _$ x
6 c% e: M+ m7 ]; ~) eturtles-own9 O: A9 q4 s5 Z1 t% i. V5 X
[
* V; Y: C" C5 k4 W. y speed ;; the speed of the turtle
; m/ X" q6 j; V2 ^& J! _4 c% z, D up-car? ;; true if the turtle moves downwards and false if it moves to the right. {: S0 u2 v: N! s. W: P
wait-time ;; the amount of time since the last time a turtle has moved
( L; _* T S: Z* G2 T6 \9 F]
2 o- q1 u. B; d# @0 z2 \; E, P( ~- Y1 u+ y/ X% m& ^7 e+ K
patches-own
% ^- B. t+ _, d" q. f: h[
4 C- b& X- i% x* |$ c5 Y) W+ X y( P intersection? ;; true if the patch is at the intersection of two roads# f8 z7 z- o5 i! L2 Y% H; J& k8 S
green-light-up? ;; true if the green light is above the intersection. otherwise, false.- Z G3 x2 o5 q, t
;; false for a non-intersection patches.3 l+ r9 `7 P0 T5 k/ c' y
my-row ;; the row of the intersection counting from the upper left corner of the
) R% l n r0 I, B0 W ;; world. -1 for non-intersection patches.' h* `. W- O9 |9 U
my-column ;; the column of the intersection counting from the upper left corner of the9 } e! g$ @! o" x" t8 f1 [
;; world. -1 for non-intersection patches.
1 ~$ {+ c" f9 s& ?0 A) w7 s% h3 ] my-phase ;; the phase for the intersection. -1 for non-intersection patches.
8 J; L, R# p" @( Y$ Q' @ auto? ;; whether or not this intersection will switch automatically.6 n& I# e; a2 B+ M6 X. c
;; false for non-intersection patches.4 N- Q6 U9 B( W9 D, ], O
]
; z. h2 m# ^1 k; F0 D/ D' a i$ l) O; M
6 }" H. e" w' M0 y
;;;;;;;;;;;;;;;;;;;;;;6 k* C# m" G8 [& ^1 k" V
;; Setup Procedures ;;) Q3 J. U% w3 w+ y0 W! l2 m" U$ _
;;;;;;;;;;;;;;;;;;;;;;
& ], f+ V. r2 B4 \8 A9 D
8 \7 A( g: g( U! a& d# L# x1 U3 \;; Initialize the display by giving the global and patch variables initial values.1 k5 W2 C1 |6 y! D8 x* X
;; Create num-cars of turtles if there are enough road patches for one turtle to# k: ^5 f: J8 Z) V0 C) h% w$ I
;; be created per road patch. Set up the plots.
. c. g+ j) S: e4 |to setup3 J9 N$ l6 l \5 R2 A- ^
ca
1 A* m, c4 C/ c/ w. T4 l/ _ setup-globals" B$ O9 p# a6 e
4 ] Z% v/ q" i ;; First we ask the patches to draw themselves and set up a few variables
7 T8 } _5 s6 g C setup-patches
' w6 j. G+ d7 X' L! @$ }7 I make-current one-of intersections' [6 v7 Z: [$ I0 Y, }% c) f8 e/ _( M" l2 Z
label-current
( _) T9 f5 D, L" V7 L
J/ t- q, t% ~' ?) S set-default-shape turtles "car"+ J* z0 O3 d. t! Y1 }6 _0 m7 v
1 }2 e( d. J- z6 [1 E if (num-cars > count roads)
0 e, w$ d* b! o [
8 o7 U4 i7 \* c" g2 X( n- | user-message (word "There are too many cars for the amount of "' F+ K k& l! L, e
"road. Either increase the amount of roads "2 X4 @+ P, ~. o0 g
"by increasing the GRID-SIZE-X or "# L: S4 s. \/ l! ]! i D
"GRID-SIZE-Y sliders, or decrease the "
4 N- s2 O2 L, v( Q "number of cars by lowering the NUMBER slider.\n"3 k l1 X9 R6 k: _
"The setup has stopped.")" h% f- [, S! ?" g& G* s
stop: a+ j0 h" L/ i
]
: d- b# Y! E" f. T1 y
; s% g7 l0 P$ j) H9 Z ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color# i6 j' b! W* B
crt num-cars
% i' e% S* A6 ~- u4 U% ^ [. O& c' X% B4 [5 H2 a( }1 [0 b( y
setup-cars
0 c" t8 h' z1 q5 B, e: c set-car-color
: V& _: s5 O# x" e/ h; K record-data
' h/ I! {7 _5 y6 p% e ]- u" m8 J6 j# v# i3 N3 s
* z2 R) |: P0 }# ?5 G ;; give the turtles an initial speed: Z! X! d# g1 e+ Q0 Y: k5 V
ask turtles [ set-car-speed ]# l4 G/ g& J2 X+ ?3 O2 K6 a
/ j5 Y: _& a* w# G/ m
reset-ticks1 w! b6 A8 T; w
end
6 R6 s# S2 w4 L8 p+ Y6 Y4 e- @& I( m
- B/ T. |& }$ i. P! i3 W$ e0 s;; Initialize the global variables to appropriate values+ S/ z7 y! h/ V7 z, e% |! I* `& t
to setup-globals# S& N, r( Q/ U$ _3 L
set current-light nobody ;; just for now, since there are no lights yet* ~( {/ {$ V0 D- W1 @8 f
set phase 0" w' C) a( P. c5 e I
set num-cars-stopped 0
/ X) M m, i# V+ y) e1 j set grid-x-inc world-width / grid-size-x( \* B2 W Q9 X+ {
set grid-y-inc world-height / grid-size-y
' z* T( K4 p3 h! c* Q, z; t+ |7 ?2 t. N" |7 y
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary* v" D9 H. O9 n0 K! y) }9 T* _
set acceleration 0.0993 X' @; S6 Q: R
end
0 q# N0 ^8 q7 K) \9 \0 X2 e! G) q! O! Z! P) b( v3 U* x
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 J( Z6 d- D- L' l+ ?. _;; and initialize the traffic lights to one setting) G& M4 b! S b1 g6 p0 Z; Z
to setup-patches- c7 o& P- e6 z, T! L
;; initialize the patch-owned variables and color the patches to a base-color
" ~! [# Z# s3 [% l. J1 V ask patches: T8 I+ m6 K( s+ j; e
[2 j& r0 x4 w. }0 |4 F
set intersection? false
! N1 ]: ]6 x: X/ W set auto? false5 `; z( J/ ~! @; a: r4 W
set green-light-up? true0 y$ u$ X( k/ ^$ I1 U* A
set my-row -1* P9 h. Y) p. k- \8 R# R6 U
set my-column -1
/ p8 p& g9 ?! }' `2 q set my-phase -1& l( G$ e1 [4 z0 _1 a
set pcolor brown + 34 a7 S- W6 i" a' B d. c0 G/ b
]
5 Y4 \# _- n$ Y0 x; \2 O0 n) o+ n& \5 s) ~! n2 H% `8 B
;; initialize the global variables that hold patch agentsets
! p* E' c. B$ n7 |! L set roads patches with8 O& I% B6 H( j& a% j# d
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, p4 H% L- e. q( c& z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
U3 H$ v; Y- ~' Y set intersections roads with1 D4 [; I+ i) m
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and( M, ?2 R5 Q8 j' y: ]" [6 N
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 B H9 `3 d8 P5 B [0 H( J
# a2 R+ X: K/ t2 u. ^5 h( z ask roads [ set pcolor white ]
2 V- R$ s* _7 g2 P setup-intersections d+ x6 Q$ f8 \) u! ~
end3 {$ m# \3 K! `2 y& ^3 `7 j7 j
其中定义道路的句子,如下所示,是什么意思啊?* R* I/ d, A3 b4 @
set roads patches with
4 K' J0 N3 ^3 }4 C% Z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or8 s1 }; Z W( W2 }+ d! C- r
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 D/ @8 K0 @4 g l谁能帮我解释一下[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0)是什么意思吗? |
|