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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。; q8 k& [4 Q: O6 t3 a/ T
netlogo自带的social science--traffic grid这一例子当中,/ Y, ]9 _, J U! k( h. ^9 k; A
globals4 t4 E1 Z& i! T$ I2 W- x! ?2 ]
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grid-x-inc ;; the amount of patches in between two roads in the x direction( m9 q& `1 {/ J6 y
grid-y-inc ;; the amount of patches in between two roads in the y direction
7 e* K# a+ P6 k7 P( B+ U acceleration ;; the constant that controls how much a car speeds up or slows down by if; }: j4 d* `8 V/ S7 C# n% d
;; it is to accelerate or decelerate( T# T2 T5 I; X$ y! g' V
phase ;; keeps track of the phase, I6 ^- w' O3 X# b8 n$ r' M
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
! A0 Q1 s- N3 [8 \ current-light ;; the currently selected light
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, G/ \/ z5 g' c' \ ;; patch agentsets
# J& { r3 n6 z2 ] Q, w intersections ;; agentset containing the patches that are intersections
K" H( ]( e* B' E5 ^ roads ;; agentset containing the patches that are roads
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3 n8 @# C% C$ \; E- Z- ]turtles-own
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9 w, k. z( Y2 [8 T* S$ Q8 S4 `6 B speed ;; the speed of the turtle$ X- r! X2 u* z- i; c
up-car? ;; true if the turtle moves downwards and false if it moves to the right8 L4 J! g1 d2 o+ o
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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: @8 o. o1 M: t0 _8 V- ] intersection? ;; true if the patch is at the intersection of two roads
# m$ J4 B! a4 F4 }9 j. x green-light-up? ;; true if the green light is above the intersection. otherwise, false.7 w) o3 h! F: L3 a6 v3 k
;; false for a non-intersection patches.
! M$ c) ?4 y" g; B my-row ;; the row of the intersection counting from the upper left corner of the& E: s5 B8 E- k; C2 ~
;; world. -1 for non-intersection patches.
8 u& P0 x, y- t9 V my-column ;; the column of the intersection counting from the upper left corner of the
$ M" ` A( w& B/ X8 q' s+ x6 M ;; world. -1 for non-intersection patches.
& u+ W( D* ?- t9 h5 {5 T, p my-phase ;; the phase for the intersection. -1 for non-intersection patches.5 o: X# u" y" h3 p3 ~0 e) o9 \2 j
auto? ;; whether or not this intersection will switch automatically.- L" Z' v+ S3 p
;; false for non-intersection patches.
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) q' X2 Q: f# T+ a$ U6 s;;;;;;;;;;;;;;;;;;;;;;
; h, s' R$ I$ J* i& L;; Setup Procedures ;;8 T5 r- X2 W2 W& m+ X2 \$ s; |
;;;;;;;;;;;;;;;;;;;;;;9 T1 m# R9 ?2 Y% j0 L( F
7 [% P: a4 c3 `: C;; Initialize the display by giving the global and patch variables initial values.* b9 }) n& S+ d% z- n R
;; Create num-cars of turtles if there are enough road patches for one turtle to# m+ J/ q6 m# P, U- R" S
;; be created per road patch. Set up the plots.9 a4 K5 ~2 Y* ~9 W
to setup
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setup-globals2 l! n# i2 I" |, z
; s0 h0 r# h& F7 ]7 U9 x ;; First we ask the patches to draw themselves and set up a few variables
) Q ?) c; P+ B* J3 J setup-patches. L" F2 f% _* v. W/ x; Y
make-current one-of intersections
+ {6 Y6 k ~1 B; r# ` label-current
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4 U1 F% T; D" F set-default-shape turtles "car"/ I8 G4 V' g, w8 Z
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if (num-cars > count roads)9 M8 f4 w' H; \7 }8 t6 |& H# a7 K
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user-message (word "There are too many cars for the amount of ", F$ S) j& j) ^" f
"road. Either increase the amount of roads ". k6 A% _9 ?3 v R4 `7 W' ^
"by increasing the GRID-SIZE-X or "
/ a$ H- N- K% s- G "GRID-SIZE-Y sliders, or decrease the "7 D) T, c) Q5 V8 A' Z/ l2 N5 X7 h8 ?
"number of cars by lowering the NUMBER slider.\n"3 g0 a! J" W: m8 g1 h" u! M w
"The setup has stopped.")
4 k; W$ q9 d. `9 R- b$ M% Q stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color; x# X- h* Z# X: o
crt num-cars
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setup-cars
- r) O7 Y: s8 `5 z" D" j, \; n2 m set-car-color4 H- B9 k$ f" W- h$ d' i* l4 l
record-data- H; V# j8 l6 f2 R2 {$ n
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' y) g R6 g% U1 k( j' N ;; give the turtles an initial speed9 W7 u3 o2 f3 u& |' B+ B- ^) q
ask turtles [ set-car-speed ]5 }+ A' F5 q, W: J
7 n% }1 v4 h8 v/ z' h$ r) w) y reset-ticks b$ P; X3 [+ n4 k) ~1 |8 {% ~3 |! L
end
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: Q' a+ \6 M- Y( b$ h9 C) N;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet' [1 v9 G8 h0 i
set phase 0
8 M; V4 ]6 W1 `6 d set num-cars-stopped 0
% \, H7 U* |& ]! C; J set grid-x-inc world-width / grid-size-x! S+ s8 a1 e9 M z
set grid-y-inc world-height / grid-size-y! s, G: S9 i0 S/ k" e6 S' K% L
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
5 }7 v# t- m; A8 \$ o set acceleration 0.099
3 Y6 l7 L6 X. R# V9 a- nend. O- V2 Q( {$ ~" \8 [* M! v
. Y1 `' y Z& @/ _* i/ R' V;; Make the patches have appropriate colors, set up the roads and intersections agentsets,8 j' _9 P9 c8 ^0 J0 [1 a
;; and initialize the traffic lights to one setting7 A8 x$ U' [" Q) ] ]" i: T4 t7 r
to setup-patches) g5 w0 g4 M# y! @9 }* T. h' y
;; initialize the patch-owned variables and color the patches to a base-color. ~, T' ^* D5 j7 W! q5 W; K! q5 U
ask patches
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' F2 J! m% [! x! H1 ` set intersection? false$ H% V0 X- p2 W" [! e q
set auto? false6 x. i. P9 W( R1 u$ N* ]4 G: V N
set green-light-up? true" E0 H# g* f! p5 H0 t' F6 Z3 @
set my-row -1
- K- B% E: A- I3 \7 U7 G set my-column -1) V& j I1 h( d z# I% y% H6 r
set my-phase -1* M7 Z9 p, Q4 m2 C! P5 }3 M
set pcolor brown + 3( ]: x: x9 p& {( ]- N
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;; initialize the global variables that hold patch agentsets: `: D# {9 s- b. g d! f/ M
set roads patches with1 j2 S {! P# L/ }) Y- M8 V1 c
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
& i' Y7 F% z$ u6 t1 c- q# a( Q9 ]2 ]' v (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) y' U0 c( S" S; ]5 ]5 r. i$ V: `2 B
set intersections roads with+ b& b" y) I% e1 p$ v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and! v$ Y; k& P' Q' d
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]* V1 X$ ]( W; F* _+ [
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ask roads [ set pcolor white ]
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end) z/ @2 J2 R2 y9 X
其中定义道路的句子,如下所示,是什么意思啊?$ O! V0 J9 z& l: \5 Q0 M
set roads patches with
- k% U5 j+ t& g- \( \ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! h# T) Z# ^0 |7 p+ u5 z% ] (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 O3 k5 r; b& G7 |" {. z: a1 P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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