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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。
9 `4 I, ?: O/ m0 \" M8 K) D! Z* {netlogo自带的social science--traffic grid这一例子当中,
; x) J0 _7 @5 z& Z5 n3 N3 iglobals o2 D# _; c! J
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grid-x-inc ;; the amount of patches in between two roads in the x direction
) J- ~4 u' E0 h7 G8 u) _ grid-y-inc ;; the amount of patches in between two roads in the y direction
# [, k2 X H' G; ]/ B3 c% h; { acceleration ;; the constant that controls how much a car speeds up or slows down by if
. e, k5 w, F: |* x E/ E9 V6 U, g ;; it is to accelerate or decelerate; Z* r( |" w' y) i0 t L/ [+ k. E8 |
phase ;; keeps track of the phase
) T* d# A( U: C" Z& F num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure2 U8 X$ A+ j/ V" j# c' S: v* ?
current-light ;; the currently selected light$ M$ f$ ]! b. n. G/ p' m
, e5 c# m5 p: g3 L; N! ?. n8 j ;; patch agentsets% w2 y% F# {# U6 r1 J
intersections ;; agentset containing the patches that are intersections9 v/ w, ~& L q. U% ~' E2 {8 g Y4 D
roads ;; agentset containing the patches that are roads9 m/ l/ H# |; X3 |$ o
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9 m; n+ a8 H0 O8 Z; K3 A7 G2 {turtles-own
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speed ;; the speed of the turtle5 ]8 T1 O3 M9 q, E
up-car? ;; true if the turtle moves downwards and false if it moves to the right3 I# V* U- S9 f1 y% @' S
wait-time ;; the amount of time since the last time a turtle has moved
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, d, H* T( k2 r: Upatches-own
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D+ v$ X4 Y$ G4 e) B% G4 s intersection? ;; true if the patch is at the intersection of two roads
9 r$ b- p+ E% V& X* p( K green-light-up? ;; true if the green light is above the intersection. otherwise, false.
7 O1 g1 _! ^- c" f- `1 k! W ;; false for a non-intersection patches.
( W+ `. p! h/ x/ u& O c( R" u my-row ;; the row of the intersection counting from the upper left corner of the) `3 R1 M2 c8 H7 R/ h
;; world. -1 for non-intersection patches.7 \" t) `7 W3 z% v9 [" c. D
my-column ;; the column of the intersection counting from the upper left corner of the6 Z$ Z5 r% H! g" D) W; E
;; world. -1 for non-intersection patches.
& q) a& {' V9 z: T c2 O: J" _! A; N my-phase ;; the phase for the intersection. -1 for non-intersection patches.: O" \9 V4 a: s3 b$ x* C
auto? ;; whether or not this intersection will switch automatically.% L1 `7 D0 [0 \, c7 K
;; false for non-intersection patches.0 L, O. f% v1 D
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+ N2 Y0 u8 A+ O;;;;;;;;;;;;;;;;;;;;;;2 E6 r- r% m4 O$ g2 u1 a& V
;; Setup Procedures ;;2 i# ~1 [, B' [1 c* r( y; j. i/ c
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
" N C$ e$ R* G3 ]2 R. l8 c. k;; Create num-cars of turtles if there are enough road patches for one turtle to
& \7 b7 z( |& n$ v& m;; be created per road patch. Set up the plots.
" p9 W: o. l: A6 Cto setup/ o4 K2 d4 G! Q. h A
ca
: L* u. A3 C) r7 r) i setup-globals# p7 m$ J! G/ L4 X
1 V' L" l% K9 J2 n* w( ? ;; First we ask the patches to draw themselves and set up a few variables3 P k, c8 |- m7 w
setup-patches' Q+ s% Y, Q( A4 A8 G& ~7 b. J
make-current one-of intersections& y( H- X* p" H9 g* n
label-current
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set-default-shape turtles "car"- ~4 X, X6 o: [) D% i! v
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if (num-cars > count roads)
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: Q/ V( X) b- Y* |( w user-message (word "There are too many cars for the amount of ": q+ ] A) w! s3 p2 Y# u# e: S6 s
"road. Either increase the amount of roads "8 v) B1 A: m' p& o& Y
"by increasing the GRID-SIZE-X or "5 n3 ?/ S' u6 I
"GRID-SIZE-Y sliders, or decrease the "+ |+ U& o( x4 I% @: o% z/ i* O* c
"number of cars by lowering the NUMBER slider.\n"
- v# x/ z: U6 x, j+ c, O "The setup has stopped.")' j( @+ o- z+ h+ N s! \ p& D
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color7 N1 I% K8 M$ J0 P
crt num-cars
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setup-cars; w' ? S1 l0 e+ J( ?, t
set-car-color+ j! r! Y! h3 U, V
record-data
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;; give the turtles an initial speed
% U; V4 E3 A @; e* w ask turtles [ set-car-speed ]* j C4 ]. |# L) O
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reset-ticks7 j$ |7 E8 \+ X" o: f$ d& ~8 b( `
end- B7 }8 R( q5 _+ r/ N: L' ]/ N( @, c
. I. y% y5 h5 F4 J% E7 u& z;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet/ h; K4 \$ L! O1 y1 q8 C3 Y
set phase 0
: v# `: k. F% T. q# p N- V) l set num-cars-stopped 04 v5 |8 Y: b( G7 F
set grid-x-inc world-width / grid-size-x
2 V0 c" g2 P, a$ X) A set grid-y-inc world-height / grid-size-y
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, }2 \+ N8 j+ `* u- ~' T! k; }6 Z ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary+ m+ u0 @$ H; O8 ^8 g$ \) r* q o
set acceleration 0.099
* v9 D3 e* l _7 c1 Pend
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$ O% L8 i& R0 D2 m" R2 y, s;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
6 N, d+ c( N; o3 r* J;; and initialize the traffic lights to one setting
* h* z K$ f2 b, P# P& M/ Y. w( Pto setup-patches0 q- b0 \1 Y! E0 g' c
;; initialize the patch-owned variables and color the patches to a base-color/ G& [, L& ]* s; v, `
ask patches" b: s' m, R8 J: T$ }; L
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set intersection? false6 T4 ]6 M# }4 p( e4 P4 f0 u. q
set auto? false
. a6 O, q0 K6 E* g% G3 l9 \6 ?6 B set green-light-up? true8 T3 Z2 A: r) Z# I4 p
set my-row -1
+ U. W0 T* }1 W8 p set my-column -17 [* I' x) J4 _) _3 @
set my-phase -1, ]4 }! N9 M# g. s" ^+ d
set pcolor brown + 3
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9 b+ i \# H# I ;; initialize the global variables that hold patch agentsets: N; m3 p: t) }. `# a- \0 ^
set roads patches with
) F) y' H4 a6 k. b* U: Q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
N: B7 T# F6 _- j% M! M- l (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 T9 J9 x3 J" W4 Y$ c$ @ set intersections roads with7 W: `' E3 O# V1 L7 g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
% f. P C0 T6 a0 m% a2 ]! t (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
7 @6 U3 u7 k# Q1 b) o0 ] setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?/ Z0 ~' E, t1 X4 K' i( j
set roads patches with
+ b9 R# M* g2 M8 \) n6 A) R' f [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or1 M# z7 Q i6 C! K V# w
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 I# }7 P# i; p: b6 H$ y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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