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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。 H7 Y0 R' ?* s
netlogo自带的social science--traffic grid这一例子当中,
5 q T8 u3 z- R9 D. T" ?# |2 |globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction7 R% f7 `; z8 _8 `+ Y4 x$ ^
grid-y-inc ;; the amount of patches in between two roads in the y direction" ~ o: h$ `8 \6 U w1 n& n4 P f1 [) T- j
acceleration ;; the constant that controls how much a car speeds up or slows down by if
2 @3 ~( P2 d; }5 K& e$ @' Z ;; it is to accelerate or decelerate
, U* F) B; X, A/ V3 p$ B0 c2 C phase ;; keeps track of the phase) W0 ^1 o. ^+ y3 M
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
/ h5 j' _8 M: m# y current-light ;; the currently selected light
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7 a1 q2 c2 k/ N/ M) N ;; patch agentsets& R' {2 i# S7 j* F8 O% C
intersections ;; agentset containing the patches that are intersections
: I, x: x1 r# T7 q3 V roads ;; agentset containing the patches that are roads
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+ S( Y a9 x% T# U4 ?3 w0 m1 [ qturtles-own* {0 p O, K( o- N1 q* c+ s& u
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speed ;; the speed of the turtle- a7 P; F6 {9 z. w6 z- Y
up-car? ;; true if the turtle moves downwards and false if it moves to the right
& w7 r# L. ]# Y% Y5 l+ w1 O! L5 d wait-time ;; the amount of time since the last time a turtle has moved
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- j% X8 i; ]2 n5 k" Vpatches-own5 h6 g/ i3 X9 U8 f* d/ b
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intersection? ;; true if the patch is at the intersection of two roads
L0 P3 B& t! f9 Z8 t green-light-up? ;; true if the green light is above the intersection. otherwise, false.( X0 \) O. H9 ^' P; v& U" C7 J6 s V
;; false for a non-intersection patches.- n2 O4 R) \0 a7 m! W: v) r- c' G% W
my-row ;; the row of the intersection counting from the upper left corner of the+ w5 m" e2 `: P3 h6 U% O
;; world. -1 for non-intersection patches.7 n) k1 O; y# T' d* g
my-column ;; the column of the intersection counting from the upper left corner of the
; H0 k: V7 z' M5 b5 B ;; world. -1 for non-intersection patches.5 ]3 \. m7 ]: h) X
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
/ q. Q# r6 i8 t auto? ;; whether or not this intersection will switch automatically.- Y, [+ _! }* s
;; false for non-intersection patches.9 P L4 k2 e. {# ~# g
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;;;;;;;;;;;;;;;;;;;;;;) M# {: D: G I- [7 j9 k
;; Setup Procedures ;;5 t+ h! R2 G. D) _ i+ Z2 h
;;;;;;;;;;;;;;;;;;;;;;! G) [, X V/ t
8 y- t2 \) _7 K/ e;; Initialize the display by giving the global and patch variables initial values.8 E! `4 g2 K, w: F& K9 t
;; Create num-cars of turtles if there are enough road patches for one turtle to
7 [0 D! c5 Z! Z! D& c9 b) U;; be created per road patch. Set up the plots.4 }1 X1 e b0 Q4 L8 O4 l3 f# i
to setup) O2 z) R/ a9 ]* h9 G7 q& l3 P
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setup-globals. v3 {/ h' C2 c
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;; First we ask the patches to draw themselves and set up a few variables
4 q( s( B0 u# w, P8 `! H& r setup-patches
3 o, O3 @. B8 t) c make-current one-of intersections
' q- }' G; W2 s$ [6 a% Z1 ]* R9 j label-current
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set-default-shape turtles "car"$ V4 G. a2 t' U+ m' {9 ]3 Z
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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 "
: P# u9 b/ b5 `, g, @6 m' x "road. Either increase the amount of roads "
# p1 [* r9 @2 d9 K "by increasing the GRID-SIZE-X or "
+ Q) X8 Q2 c) f; H' r: f/ |. f+ m "GRID-SIZE-Y sliders, or decrease the "" N4 o' j. h) t% ]: m$ S
"number of cars by lowering the NUMBER slider.\n"
& z$ o5 n2 a C( ^1 d+ Q "The setup has stopped.")1 E! _1 o; S9 i
stop
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% f8 Z6 z# c) R ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color& Z. z0 c3 _; U8 U' L
crt num-cars8 L; H1 ?& e; m6 x, ]0 Y, z9 r
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setup-cars
+ U$ a$ O6 c, X' E* |! Q2 w1 I set-car-color$ m' K2 y5 ^. }- K6 x# T
record-data
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;; give the turtles an initial speed3 _6 L, m( Z6 c$ d% _
ask turtles [ set-car-speed ]
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: ~4 `1 i% d$ S+ @ reset-ticks
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;; Initialize the global variables to appropriate values
0 `. \0 m9 u. j! {: L) Y4 Uto setup-globals
7 b+ x! G6 w8 d8 i set current-light nobody ;; just for now, since there are no lights yet* A! s5 }$ N& }/ k/ N
set phase 0+ o1 {1 V0 v X& ], [. _. Q
set num-cars-stopped 0+ D |8 j6 E, T4 N
set grid-x-inc world-width / grid-size-x
9 V: L1 g3 s* I( a set grid-y-inc world-height / grid-size-y, _ H, Q+ c' ?3 a0 {0 p
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
; k1 J% K1 g; V2 r9 r1 v set acceleration 0.099
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2 v' M* A% h- U5 m- C;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 w3 w& h5 U9 A8 t J;; and initialize the traffic lights to one setting1 W9 D. \$ {9 ~3 ^2 w& F- h( ~
to setup-patches
# J6 G. \ f6 K5 D ;; initialize the patch-owned variables and color the patches to a base-color+ L) Y/ r8 D. h: W5 y& D
ask patches
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- K* B% A8 v8 Q set intersection? false* {" ?7 U F3 @9 F
set auto? false1 r1 t1 c$ n) D# D/ f
set green-light-up? true
$ d# \% }" {% Q; x2 V1 q" e2 t set my-row -1
3 d8 |5 D( F& `1 p) a9 |* A+ h set my-column -1: z2 Q" R' g. X! W, U/ Y0 K9 ~6 K
set my-phase -1
$ e: {$ K. \( z4 M: R set pcolor brown + 3& o8 X S- j e: j7 N
]
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9 T$ w' U ~2 ` ;; initialize the global variables that hold patch agentsets
( B- i5 z5 @& X. _% w8 _! f set roads patches with' X% V, V: E/ P
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; O, `+ H- x2 q* |% O- N t
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 g3 p. i0 S+ L5 A
set intersections roads with' A7 D( H: F/ s6 T; s
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and6 A& v/ F% b5 z0 j
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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: C) d6 p/ N) n ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?
& R0 X; g h; f+ b% i, V- D set roads patches with
, ^2 i; N: |3 H( Y2 y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- Z9 S, f* {# _' Q3 } (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; s2 T8 M7 e" d- P+ s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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