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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。. L& n0 ?" \! {3 v5 k
netlogo自带的social science--traffic grid这一例子当中,
# k& J5 J7 R9 I! }1 ?# u" aglobals- h! e& l9 |& C+ L* r" y+ P- }
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4 _2 X$ Q- U0 H/ C* u grid-x-inc ;; the amount of patches in between two roads in the x direction. k5 f% G5 q! ]* P) q# X$ j
grid-y-inc ;; the amount of patches in between two roads in the y direction
( V% Q5 _! u4 B- Y) R2 f+ q g acceleration ;; the constant that controls how much a car speeds up or slows down by if
. T% `1 y+ Q0 J1 B( ~+ O ;; it is to accelerate or decelerate' v+ u, d+ E8 s" _
phase ;; keeps track of the phase
3 L4 b$ }8 J) T8 G& q num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
! d' P q& j, c' A. j current-light ;; the currently selected light7 f6 G2 c, t2 r2 [
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;; patch agentsets/ F1 \' f5 V1 ~* v) [+ p1 v" I5 a
intersections ;; agentset containing the patches that are intersections- v9 c/ I6 L6 V) L
roads ;; agentset containing the patches that are roads
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, P' Q: t2 h u* h5 d6 Fturtles-own
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2 U# M6 r5 H' W( d: C speed ;; the speed of the turtle# n! U$ X }% y7 c# h Y& j
up-car? ;; true if the turtle moves downwards and false if it moves to the right9 s, m S4 x P9 v
wait-time ;; the amount of time since the last time a turtle has moved) n" n* {& g, M/ B, v: {6 L
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5 m8 N, u, o- p3 o) T: m8 l7 n1 Cpatches-own P6 z! Q* E2 p$ C+ s
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& Y N0 c% s% |: E. B7 }" h/ y' i intersection? ;; true if the patch is at the intersection of two roads- b+ E) P0 c# R
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
- X6 w ]# B! r. \6 [3 r$ m0 K% P ;; false for a non-intersection patches.
4 r% f" D% P) Q. V0 l my-row ;; the row of the intersection counting from the upper left corner of the
. h( `( z- y, X* b' B+ N ;; world. -1 for non-intersection patches.! S, k- V6 K& P: ^) m- F9 a
my-column ;; the column of the intersection counting from the upper left corner of the
. K: P& g; o8 ^8 R ;; world. -1 for non-intersection patches.( a6 d: n8 j9 h
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
# C' M7 H- E5 k2 x i* {+ } auto? ;; whether or not this intersection will switch automatically.
P& X- P# C8 F. o" ~7 @4 X ;; false for non-intersection patches.
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! W0 n& `/ U4 }2 v. P9 I7 u;;;;;;;;;;;;;;;;;;;;;;/ O; o: p2 u/ {1 |% j$ W2 ~
;; Setup Procedures ;;
3 G) w. F& z2 f) K5 y4 T# E' l;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
: t3 R# V, x, {( k;; Create num-cars of turtles if there are enough road patches for one turtle to$ z3 x2 t3 \/ [
;; be created per road patch. Set up the plots.
% I' f! V0 n2 M$ v. ~: Z& xto setup$ A# _. S& B$ k: @- _ p
ca
* x8 K/ x( H) Q' c- d9 n setup-globals! Y$ T; X, U; t6 O- t, X& p
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;; First we ask the patches to draw themselves and set up a few variables
7 q# Y2 J+ E* x) W# { g( X setup-patches( p: R* B" { K2 w9 k8 N
make-current one-of intersections2 S! ?- ]+ Y5 I, @0 K
label-current
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( _' ~' O) ?/ n+ K set-default-shape turtles "car"! S) }' m! D: s
) \8 r7 D( _. N, R$ Z& { if (num-cars > count roads). j: }/ R& Z1 a8 s
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user-message (word "There are too many cars for the amount of "9 m+ d5 s9 d [3 d: D4 J
"road. Either increase the amount of roads "
I9 r, | H$ i& I3 }/ Z "by increasing the GRID-SIZE-X or "
2 l5 p1 a! P3 C; t: Y8 \7 C% |! i7 {3 B "GRID-SIZE-Y sliders, or decrease the ") G' S$ |% _7 ?
"number of cars by lowering the NUMBER slider.\n"
0 e T: `4 ?7 a5 F! N# {, ^0 @ "The setup has stopped.")* Y3 \( h/ U" \3 k& p# e$ p
stop
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" h6 X$ }, i5 Y1 c; H5 {2 A- X3 D ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
+ c2 X) q# X+ t: o crt num-cars$ D% T* t6 e1 W+ m8 t' H+ m, G$ b
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setup-cars! c' c" [# p' N7 }' K* J/ j5 ?
set-car-color
8 x D) f9 i; I! S* t/ C: r; {* a record-data
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+ l, U& h5 T$ E, Z1 A ;; give the turtles an initial speed9 W- F4 L( K$ ^5 G% w
ask turtles [ set-car-speed ]4 T/ n7 l9 }' c: x3 ~
, _$ _' x7 m% m* j reset-ticks6 \* O" b, P$ S5 Z4 P$ b
end- k! i% C7 k4 X+ L0 }4 z
! F7 P ^0 F8 G" q8 c& N;; Initialize the global variables to appropriate values
Y6 |$ b$ _3 n, G, N$ `* I D4 qto setup-globals, ~/ Z. z s6 m
set current-light nobody ;; just for now, since there are no lights yet
* q5 Y' L T2 [8 h/ |6 o set phase 0
3 l7 [$ m/ ]8 B/ p& ~' t3 i' d3 ^ set num-cars-stopped 0' o; o: k( \/ {+ m/ J& W7 R+ s0 [
set grid-x-inc world-width / grid-size-x4 s4 q4 C# J/ ~4 P( i/ E
set grid-y-inc world-height / grid-size-y
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# t, n+ A* y9 @8 G$ Y) [& ` ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary9 T; T8 I* ?0 `5 F: p
set acceleration 0.099- }7 r( s$ G" ^1 z5 V) k7 h( ^
end( r8 J |$ G, F
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
/ ~) v4 J W( J$ V* ?;; and initialize the traffic lights to one setting% u5 B3 K/ V5 Q2 S# x: o7 J/ r5 [5 e
to setup-patches
. F% f8 s6 U, T& p$ T% E4 d/ ^ ;; initialize the patch-owned variables and color the patches to a base-color
1 V' \' a c& y+ O& Z) { ask patches
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set intersection? false Y8 C# [3 e1 B% Q% O6 _
set auto? false
" j0 ]% k2 }' J+ { set green-light-up? true3 ]+ r" C# W$ O5 Z
set my-row -1
7 }* B/ M. Y* M! s/ W$ ] set my-column -1
2 B* Z8 i8 `3 a4 s set my-phase -1
% e1 I" |6 ]' Z1 X* r" x9 `4 e set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets$ b2 |- ~; ~7 q
set roads patches with
. Y \8 K# B/ v; i: S5 s! J l [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 X: H! `6 B% [! }) X7 u" v6 p0 [
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]: s% i* j( v( l; E5 z4 J
set intersections roads with4 _0 Q& D4 m) o9 c- t8 b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and( ^: X+ w- T y4 t, ^! y7 Q% g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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' ]# f) B. @- c2 ~ ask roads [ set pcolor white ]
. p2 b3 E, V8 O2 f setup-intersections0 M' e0 r/ R+ |
end/ T! l! N# i9 s6 E% {" e
其中定义道路的句子,如下所示,是什么意思啊?
; o/ Q7 w4 z7 B- ] set roads patches with: O+ [- j* g8 o
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or7 ^9 f6 N6 f4 c7 D
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 n2 J( Z7 ~3 _6 ?! K* c
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? |
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