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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。) H' p3 `) @: {/ O
netlogo自带的social science--traffic grid这一例子当中,
2 W* ~3 a1 W8 T6 ^globals
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9 m7 ?3 H: b4 N: h grid-x-inc ;; the amount of patches in between two roads in the x direction/ P o- S/ k, V/ x) a
grid-y-inc ;; the amount of patches in between two roads in the y direction
9 _( i7 m# P T* H; V5 W# K' v' w1 V2 s acceleration ;; the constant that controls how much a car speeds up or slows down by if
* s' D3 [; x& j9 X7 F ;; it is to accelerate or decelerate
$ W4 z7 c- e1 {) J( X$ R/ t4 j phase ;; keeps track of the phase2 x; r4 F2 _5 C, c. Y, T
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure8 s9 l5 P, n. T) f
current-light ;; the currently selected light9 Z' A* E8 K! T% K5 D
8 e- q! k3 B9 C- M. W ;; patch agentsets+ K; \3 i% u: o
intersections ;; agentset containing the patches that are intersections! Q3 z1 O3 I* M( a
roads ;; agentset containing the patches that are roads
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turtles-own. d: Z; z. q7 v( s
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speed ;; the speed of the turtle4 t3 e& X% B3 |4 q/ Z+ _* a' {
up-car? ;; true if the turtle moves downwards and false if it moves to the right
- i Q% ]) Q4 M" A4 T5 i wait-time ;; the amount of time since the last time a turtle has moved! S' Z! f* [. k8 p/ W# D
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% u8 x( ]& u: |/ j0 P- Lpatches-own9 a5 s; A, Q; h3 d
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9 u2 t/ Y1 B+ ]4 A! V \ intersection? ;; true if the patch is at the intersection of two roads
3 G+ o) v- a: q7 L% y8 ]: l green-light-up? ;; true if the green light is above the intersection. otherwise, false.( @6 |- _# K3 y! g K
;; false for a non-intersection patches.; J, I! R6 W- x7 O- l6 u( `
my-row ;; the row of the intersection counting from the upper left corner of the' m& g( i7 @7 z
;; world. -1 for non-intersection patches.
$ B" g$ O; A& {: b# N6 O( z9 x my-column ;; the column of the intersection counting from the upper left corner of the, z5 _3 e9 }8 n0 U: W$ H9 H
;; world. -1 for non-intersection patches.- s( k9 c- \" g' H+ y6 ?& V
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
' D/ ~. V3 [" B% L" N& Y auto? ;; whether or not this intersection will switch automatically.5 m" J/ ]0 q. G& d
;; false for non-intersection patches.
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" P5 G$ e: v; q$ p% Z, J;;;;;;;;;;;;;;;;;;;;;;
8 U3 f5 E; \8 l$ L% D1 `# I) j, r7 d;; Setup Procedures ;;% O1 t* B8 \( D2 Z1 A# v
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
4 q- E! c% p7 p; B* {8 g% s6 m;; Create num-cars of turtles if there are enough road patches for one turtle to" N1 t6 t4 T1 @' L0 w
;; be created per road patch. Set up the plots.* Y3 J3 q8 M! y$ P; K7 K6 K5 x2 _
to setup6 Z1 _6 j1 \9 m1 u# v0 r0 h. O
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
$ ^- |9 R. {0 K8 o1 N setup-patches7 k$ y1 J# t- q/ g5 T: y
make-current one-of intersections( s1 l; z! I5 d* s: X& t1 S! p
label-current% w" X( @3 o1 m$ K' Q7 [
. O7 F% Z* J8 D+ x& Q% H0 V( e 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 "1 y9 a5 D! M% q1 l, C8 t
"road. Either increase the amount of roads "
/ V! a4 { q8 \5 x "by increasing the GRID-SIZE-X or "0 X; ^2 H6 o( Y5 T9 E* K
"GRID-SIZE-Y sliders, or decrease the "
/ W* o4 m' {! e& w( i "number of cars by lowering the NUMBER slider.\n"
0 p& e; c: v6 ^ `" ?2 w "The setup has stopped.")
# W7 r! k2 m8 p; D4 r+ U) h$ C& K stop
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- t# r0 ]5 ]8 L6 C2 ]% h/ ~ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
& l8 a! M( P! x4 W crt num-cars! ]" u* Z: h. J v
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setup-cars/ @ ~0 g% E3 `' \" \* x& ]. n
set-car-color) U% W, ]. g8 a" g) K- P
record-data
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;; give the turtles an initial speed
. Y9 l+ U7 C, A( ~ f* V; o ask turtles [ set-car-speed ], S. f# x7 V9 a! ^# S
, D$ x6 y! _% F% u% q reset-ticks
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, u# b( T4 e3 c8 L) `% i4 o;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
( j2 H( e! n: z set phase 0# _3 O$ M, k) V( V0 D) q
set num-cars-stopped 0* U3 O) L5 ~% m9 B
set grid-x-inc world-width / grid-size-x; f) Z7 }! c. n+ @9 o$ C
set grid-y-inc world-height / grid-size-y
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" e- j& o& |& |$ a ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary$ a( T" r1 k* r$ P2 p, f' t
set acceleration 0.099
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$ m- K8 q% f2 U2 d* `+ g;; Make the patches have appropriate colors, set up the roads and intersections agentsets,- {; ^4 W i6 x" J9 w1 K$ N `. J
;; and initialize the traffic lights to one setting
; z3 o6 k& n4 c6 H# uto setup-patches' S! l- O# |/ {1 m
;; initialize the patch-owned variables and color the patches to a base-color
* T9 a: k z6 \ ask patches9 Q$ ?8 l; L7 z) }
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6 Y6 A4 u- o; }0 ?5 `+ w5 Y# K' _ set intersection? false
/ W! s3 u1 r) f/ e" A set auto? false
. Y. @% X1 {- |9 o. s set green-light-up? true
$ o4 Z/ `7 h" r! }$ t' D+ c' f/ x$ B set my-row -1# r* S& q( |1 P
set my-column -1
7 p) ]* K/ S }2 h set my-phase -1 Z& k9 D9 g8 o' U
set pcolor brown + 3+ [& S5 @( F2 |& n1 k
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! ]" V& z, {9 h( w- b ;; initialize the global variables that hold patch agentsets& G8 ^. s Z9 v- G Y1 H- j
set roads patches with
" n- Q6 ~/ v8 X+ {) ]% Y, g [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; l( t/ l6 s$ E (floor((pycor + max-pycor) mod grid-y-inc) = 0)] Y& v; ? s/ z- w" l9 W! U) I
set intersections roads with% J" C, C' K3 x" O' l/ ]6 R
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and0 j+ c1 \0 w+ O) _8 G
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]" a7 |" j k4 a0 x- F* {
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ask roads [ set pcolor white ]! m/ O' w2 h% h4 T0 r- H. D7 p
setup-intersections! W' _& U0 F, _0 A% k% l8 K
end
, m, }( D$ j# \& }: b) R2 f9 V其中定义道路的句子,如下所示,是什么意思啊?
( m! m6 w' E2 W" q! b. u/ I& N set roads patches with5 v9 Q" U; |7 \
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ h7 v( z1 I" w$ _3 r (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& X0 v: G# b c! A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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