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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: _- R9 R3 ?$ Y. ~
netlogo自带的social science--traffic grid这一例子当中,3 h% Z+ f9 M( _, e% y9 D
globals
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! o3 ?' o( I$ |# z grid-x-inc ;; the amount of patches in between two roads in the x direction( G- }. a- t! i" c/ I
grid-y-inc ;; the amount of patches in between two roads in the y direction
/ ^2 [: i6 \; _9 i" {. R acceleration ;; the constant that controls how much a car speeds up or slows down by if. m1 m, {7 U0 L% X( c3 B/ p" a
;; it is to accelerate or decelerate
* \1 X8 r& I$ U$ `- c& ]% i* ]) c phase ;; keeps track of the phase7 n+ q3 j T& L; T
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure3 ?9 O3 n2 {. I/ N: L, Y+ |4 o
current-light ;; the currently selected light- Y' J9 W. A3 \# ^7 Z
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;; patch agentsets* u* u* z. }* R8 M0 J* c- G8 f! p
intersections ;; agentset containing the patches that are intersections% g! }4 _+ K# T
roads ;; agentset containing the patches that are roads& q/ m. d0 Z# ]8 u5 O
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2 e" L" N0 @: `6 u- `5 ^( W1 E% Rturtles-own( k7 U6 [1 E- S. G# Y
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speed ;; the speed of the turtle
( h4 {5 A. u9 q, l$ ^: L# E up-car? ;; true if the turtle moves downwards and false if it moves to the right$ L- I( }" p2 E
wait-time ;; the amount of time since the last time a turtle has moved" O/ b$ U/ ?$ _: u$ f0 r5 F9 @ C; W
]
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u0 v; z( O3 d2 {# _2 Fpatches-own
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8 }$ n, b; J% u3 |5 G intersection? ;; true if the patch is at the intersection of two roads- d1 j0 R- j4 f2 u3 C) O
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
: Y g1 v6 r7 L" g- f ;; false for a non-intersection patches.: s! |7 k$ T0 I" e+ c
my-row ;; the row of the intersection counting from the upper left corner of the& o3 P# ?5 | v3 `6 ^
;; world. -1 for non-intersection patches.5 j# @6 x4 v6 y
my-column ;; the column of the intersection counting from the upper left corner of the0 p. z( }8 s# {: R
;; world. -1 for non-intersection patches.: L, j" H2 Y# ?3 O! Y( F
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
. e- F# H$ g$ \! h5 K5 `$ u+ t7 u auto? ;; whether or not this intersection will switch automatically.
, `- ~9 w* a: Z- k! J$ B ;; false for non-intersection patches.
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8 I A, r% O7 T) `" U# V; J;;;;;;;;;;;;;;;;;;;;;;
( q! _* U, ?7 Z2 Z# x;; Setup Procedures ;;
" I, K; V3 Q6 T6 O! {;;;;;;;;;;;;;;;;;;;;;;
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2 E! _% Z0 Q8 P9 `. _& i;; Initialize the display by giving the global and patch variables initial values.7 ? O$ [3 z6 R o) |% x
;; Create num-cars of turtles if there are enough road patches for one turtle to
) n5 [2 E0 j8 ?. A;; be created per road patch. Set up the plots.
p2 E6 T; z0 E0 Z+ a, ?to setup
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setup-globals' c, U+ K- K4 s
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;; First we ask the patches to draw themselves and set up a few variables
+ K8 A8 r2 T7 K r" u setup-patches
5 g- I0 H6 E+ u0 ^, x$ F/ z- ~ make-current one-of intersections
m/ k' e* M' h1 H- C0 t label-current
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1 b5 q& E* n2 h6 v4 Y set-default-shape turtles "car", W* L! C4 a6 }1 w7 C( |
" ~: X* d" c* S% K if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of " N, B" y# E$ `5 i! E/ p4 `6 \
"road. Either increase the amount of roads "( d$ F: A" P$ T) z# V5 I( @ ?
"by increasing the GRID-SIZE-X or "
# m! x6 I/ U( N o* W "GRID-SIZE-Y sliders, or decrease the "
$ _: Z. m- R5 x' H- C2 g "number of cars by lowering the NUMBER slider.\n"0 z: B% J; m( A
"The setup has stopped.")/ v8 q' |# K: a) E# O% b
stop' ~; p% r9 t" Y8 X- I( {
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# T6 L/ R4 C, T crt num-cars
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setup-cars
$ ?2 C/ z! v7 R9 r set-car-color
. [0 c7 i$ O7 Y. L( ]# K3 N" Q: Z! d3 y record-data
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;; give the turtles an initial speed
. S9 e1 ?; E$ H5 t: ` ask turtles [ set-car-speed ]
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+ e! t' a/ w* l" |; `. k/ l reset-ticks2 a" m1 r$ Z7 N- [& l
end* b* ^ ?+ w- h- M
1 ^* f$ c, Z) n3 };; Initialize the global variables to appropriate values9 A0 `& W4 n: @0 g3 I
to setup-globals
; r. @$ [6 J' a3 \3 w set current-light nobody ;; just for now, since there are no lights yet
) M5 e/ n3 ~8 }6 H set phase 0
* W7 Z+ @8 o) |/ [ set num-cars-stopped 06 G9 M8 U& F6 s4 `4 w) |! a
set grid-x-inc world-width / grid-size-x$ N9 _2 C, A. ~! h1 L9 R) v
set grid-y-inc world-height / grid-size-y; A# y* n/ k9 I U! I. C% ]& C
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary5 ]; _, ?$ j+ g" s/ R! O, l
set acceleration 0.099 n( `+ q4 [+ p
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
4 N d9 X W/ h5 y2 U3 P- g5 o6 d;; and initialize the traffic lights to one setting
4 o" ~2 E7 x( P1 Yto setup-patches* F5 O5 I8 C: r( u
;; initialize the patch-owned variables and color the patches to a base-color
! T, ]! f$ B6 o: r% G- m$ F. v ask patches# V" G! t2 ]; L( o% c$ K
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set intersection? false
2 L0 i: e$ E! A; \5 r+ D& c/ J set auto? false
5 E5 ]+ ?% S& W3 H0 w set green-light-up? true8 D- h; p1 D, E7 N' |
set my-row -1% [- y2 O9 T1 F* Q: ~* y/ u
set my-column -1
; X1 b4 K5 O' S3 X" k1 f4 c5 @# L set my-phase -1; ?2 O' |" a' x2 y
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets8 E: y7 F; f! [) [- t4 E! M
set roads patches with
1 M# _# A/ ~2 h. |+ }# D6 [ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! y" F7 ^: H+ i (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ v. E9 [9 E& A" W7 J( t7 D set intersections roads with
! G( l2 E9 \! E" s) H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
& {' z& ]/ t! N0 [3 A: V/ o5 N d% t (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) ~' j3 c, O2 M# M) Z
0 h& g" V. \# l2 l+ i4 r K9 b ask roads [ set pcolor white ]! C% ~# {& P7 u$ ~/ Y E
setup-intersections [, `$ c. K) A0 i
end
4 V$ ^* _- R% J ]- t; @其中定义道路的句子,如下所示,是什么意思啊?+ H, |- ]3 q- a/ F; f
set roads patches with
; ?& I' s( r- Q. A [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; N' E" O' ^! ?; q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]- o! b5 _; R$ J
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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