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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。( K% T, Q% ~7 k
netlogo自带的social science--traffic grid这一例子当中,
& U4 Y8 E4 [; M! q# m) S, U2 \globals
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$ C+ p- T9 [- B& a" _1 c grid-x-inc ;; the amount of patches in between two roads in the x direction2 r. d8 R) |( i, Y9 B
grid-y-inc ;; the amount of patches in between two roads in the y direction) M. D# r ~8 G
acceleration ;; the constant that controls how much a car speeds up or slows down by if
" Y- [0 i- ]6 V1 i- o ;; it is to accelerate or decelerate
: O% w2 Q$ K6 W) G" C phase ;; keeps track of the phase
5 `+ E% f; j$ u9 O num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure/ I J1 u% ?+ {6 N
current-light ;; the currently selected light; b2 D u' q* }$ ?" C8 B- J* i
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;; patch agentsets
# z! a8 p. [6 g$ o( Q5 X5 | intersections ;; agentset containing the patches that are intersections
9 {8 X; L: T5 O* Z- J1 Z" N/ h: s roads ;; agentset containing the patches that are roads
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turtles-own2 `" v# W9 S& w3 V! J; K
[
6 G" h3 z: V4 o/ P- J speed ;; the speed of the turtle
0 Y4 a1 |) }9 b- c: M up-car? ;; true if the turtle moves downwards and false if it moves to the right+ ?! m9 k V7 A, G- B
wait-time ;; the amount of time since the last time a turtle has moved: v6 Z/ }4 e9 `" u( i. D
]
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3 i! J* \" R) `" ~, G6 }patches-own
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intersection? ;; true if the patch is at the intersection of two roads1 h' h; H4 x2 `# w/ C t
green-light-up? ;; true if the green light is above the intersection. otherwise, false.+ k6 r) U* p6 \/ U
;; false for a non-intersection patches.0 K, s1 t4 V( _" w
my-row ;; the row of the intersection counting from the upper left corner of the
- {; ~! ^* w) H: F ;; world. -1 for non-intersection patches." l8 A! e( M0 J
my-column ;; the column of the intersection counting from the upper left corner of the- G) ~8 H* n! i, T) ?! E& o
;; world. -1 for non-intersection patches.
7 I2 u* `$ H+ S; o* e8 \( n my-phase ;; the phase for the intersection. -1 for non-intersection patches.
! r" k. p: ~0 m8 F: E auto? ;; whether or not this intersection will switch automatically.+ T3 t9 T Z7 o1 a& u+ T/ f
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
( L( \' K; e. q* C8 T4 ^" ];; Setup Procedures ;;& e0 F$ V. v' v8 N
;;;;;;;;;;;;;;;;;;;;;;& l0 O* B- D$ T& }3 Y8 ^
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;; Initialize the display by giving the global and patch variables initial values.1 N( |+ q3 @" }8 {
;; Create num-cars of turtles if there are enough road patches for one turtle to3 j5 P& \; d. ^
;; be created per road patch. Set up the plots., I7 e; r, O- ?) B8 L3 d% K
to setup; p3 H: `$ b- |. i1 E
ca
) f; K3 m; q' {1 \8 E: Y: a+ O) }8 B setup-globals
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2 t& F2 E1 ]; K) J& c& ~+ y ;; First we ask the patches to draw themselves and set up a few variables% h9 [! ]- I4 j- S
setup-patches
+ D( n% _* a6 e3 [' i& u make-current one-of intersections
+ _; L6 o' ^# W4 ~ label-current1 j: ?; @6 K) Z& ~1 A" \
+ d0 B L0 g( a1 P set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
4 R% _: l3 b) e% w6 \: q "road. Either increase the amount of roads "" h8 L, f+ `/ u4 d8 i' f
"by increasing the GRID-SIZE-X or "/ H% |+ m8 V5 V/ [2 ~- V6 d
"GRID-SIZE-Y sliders, or decrease the "
: K3 o3 a4 b$ G% Q "number of cars by lowering the NUMBER slider.\n". m& m$ w+ w, h8 |0 q, P
"The setup has stopped.")
. V+ _5 {4 F' g6 a: f stop
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& n* V8 a/ Z% m ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
S8 |0 Y# [. x+ m, l crt num-cars9 @) _# L2 [+ V9 q
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setup-cars
# ?( O2 B4 [( c! m$ P set-car-color
" a0 Z1 u5 l# k: q3 I record-data6 x ? w' ^% ~2 l( z
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;; give the turtles an initial speed
5 B* i# Y4 ?8 P5 v$ L ask turtles [ set-car-speed ]7 h) h$ P! c" d
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reset-ticks7 q- K! F3 ^7 ]0 t
end
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;; Initialize the global variables to appropriate values
/ P2 B! c$ v) L ]to setup-globals" s- f, L J7 q1 f) j3 ?! Y: e
set current-light nobody ;; just for now, since there are no lights yet/ _& i( u. P: F' V5 O `& H
set phase 0: P' W j% o0 R3 Y! D
set num-cars-stopped 0
$ z& J: H/ E) o+ O/ u) R7 U set grid-x-inc world-width / grid-size-x
( i) A1 D5 U8 O S% X set grid-y-inc world-height / grid-size-y Y# c: u/ f, @1 V! Y
- f W* O, e7 [; W* j( b' z ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
; W8 j" F4 `' k$ P& M set acceleration 0.099
$ W9 v: Z$ h6 m" hend
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, D! x! J9 P7 T/ \# V8 ]# M4 b1 m0 z9 i;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
8 [$ U% G& |+ G/ C9 _;; and initialize the traffic lights to one setting# Q. o1 S. L/ |
to setup-patches$ P5 H+ U! ?+ V5 |) u5 p# S. [+ Z* E
;; initialize the patch-owned variables and color the patches to a base-color
. ~4 P6 Y. I/ Z ask patches5 a4 s; Y/ U, S
[
# F( X& f& \1 f/ F3 s set intersection? false
. B' K( \0 Q# S& Y) X) J% {: H% I7 u set auto? false
" e, H/ U/ @% ~* ^: W9 ` set green-light-up? true& }& o. v% ~+ o/ J
set my-row -10 M) Z \; W1 P: `
set my-column -1
C+ t$ s5 K- X4 t2 u1 H set my-phase -1
+ M. s( p. t$ [ K9 R& T, P9 @8 t9 I set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets' U: p3 N% \! W) S7 I+ B) D& |& ^
set roads patches with1 v* g+ v% n2 K9 q* d6 m3 ~
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; f6 b2 G* d# s& k2 c4 m6 a (floor((pycor + max-pycor) mod grid-y-inc) = 0)], ?$ I% Z7 @$ c% ]$ z9 b2 i
set intersections roads with
" T( v2 n7 g/ m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
$ D( z) k i0 x4 s! f9 ~# e- O (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
; Q0 K6 z$ p% N U( b setup-intersections
3 Y. V' V& j$ A1 R" `end
! Z. m* ]% z( s# X其中定义道路的句子,如下所示,是什么意思啊?; M/ E0 {1 {7 e. n6 R
set roads patches with( t. t2 @$ \- C) {
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! A+ j, p7 _& w2 w( }! M" r# ^/ ?% G (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, d8 l q5 N0 R" M U' q" 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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