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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。( g; C' x- C, B; f5 D; S
netlogo自带的social science--traffic grid这一例子当中,
( M: i' E7 Y& P/ Y1 O- @globals$ @: T3 Y m0 P1 \
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grid-x-inc ;; the amount of patches in between two roads in the x direction3 D* b/ @3 h: @8 U$ Z w/ o5 g7 T
grid-y-inc ;; the amount of patches in between two roads in the y direction
5 j$ t% @ B' v6 E acceleration ;; the constant that controls how much a car speeds up or slows down by if
( x1 _: Y d/ O9 `& \ }3 G ;; it is to accelerate or decelerate
8 c+ V4 F1 P5 t" |3 U) X1 X$ O+ | phase ;; keeps track of the phase
8 E1 K6 K7 u4 V2 I w+ j9 ^0 C. | num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure% G1 i$ _* c7 D+ h: O& E
current-light ;; the currently selected light
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;; patch agentsets
" X* N' ?" \3 U1 s! c* H0 q intersections ;; agentset containing the patches that are intersections
2 z1 @2 i9 ^5 H. C' V* z roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle
- U: W: Y9 Z' p) R& ~. r up-car? ;; true if the turtle moves downwards and false if it moves to the right. m% {, a/ d3 q b( a& z: q3 B
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own1 g: e) o9 U! e9 _. A2 J
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intersection? ;; true if the patch is at the intersection of two roads
7 `1 M" p, z- \( M' m7 i green-light-up? ;; true if the green light is above the intersection. otherwise, false.3 J6 |+ w! }1 M, q' b
;; false for a non-intersection patches.
$ q) h: e* ^" J! J: [# \# u* A% j my-row ;; the row of the intersection counting from the upper left corner of the
9 S; ?: K3 V# ^& T+ ] ;; world. -1 for non-intersection patches.; W. w# w; S" H% D" |6 Q" G
my-column ;; the column of the intersection counting from the upper left corner of the
( e/ ^ C1 B# Y" G8 q ;; world. -1 for non-intersection patches.
e, M( s3 ^8 n- P my-phase ;; the phase for the intersection. -1 for non-intersection patches.
4 q, V* ~8 Q! P: S4 ^. ?, B5 g auto? ;; whether or not this intersection will switch automatically.
6 w( z/ `, ]/ I( D ;; false for non-intersection patches.9 u$ Q- y; i+ i$ f, B; ^
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7 v- `2 x1 L! t9 U& x6 ?* I;;;;;;;;;;;;;;;;;;;;;;
& b+ \6 N( Q- f. ]; l; |: Q;; Setup Procedures ;;
9 ~2 {3 W& {+ D$ I1 B8 L;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.: k6 [* b0 G0 ^( U9 d
;; Create num-cars of turtles if there are enough road patches for one turtle to9 I+ T/ Y& ~1 n9 K9 O" V# ^
;; be created per road patch. Set up the plots.
( R2 S. r2 ^3 m/ E( \( Gto setup( M; [+ w3 r% p4 L
ca
x; z1 t, a! ?- A$ b6 o" q setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
# L3 g) g$ J! G setup-patches
3 \& W$ ~7 c q O3 }2 X make-current one-of intersections
' A" m. n- [; f) p2 A f label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)8 m$ ~. u* } J5 m! j
[
- {+ m3 N& ` ^4 Z1 |& [ user-message (word "There are too many cars for the amount of "6 |4 v& C8 `+ y- n/ k% v: o
"road. Either increase the amount of roads "1 `/ v- L& r d( I
"by increasing the GRID-SIZE-X or "6 r1 n% D& u, l5 }
"GRID-SIZE-Y sliders, or decrease the "1 s, @/ H. ^* O% P. y3 K$ h
"number of cars by lowering the NUMBER slider.\n"
! w! G# j5 N6 Y' \ "The setup has stopped.")# o$ y1 [$ r- i0 I. e
stop& a0 q, ]4 i% A1 V, o) V% U" {
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) m8 J- |: d1 | ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color, J6 w% y ] ^' b$ J
crt num-cars
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setup-cars6 u+ t* b r% ^0 @) w
set-car-color
, z: v3 F$ E8 i0 P2 C record-data
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, k" A" R7 }- p8 L ;; give the turtles an initial speed
- _2 U- v3 Y2 K3 M ask turtles [ set-car-speed ]
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; l9 U! R1 [) d- a9 I reset-ticks3 I2 v2 o1 v) \, J% K
end Y% A2 \- A5 h$ V
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;; Initialize the global variables to appropriate values
6 g! C) U; D c/ L4 k( ?" `to setup-globals& N5 [: ?3 g/ t) h
set current-light nobody ;; just for now, since there are no lights yet0 r3 {7 T. c: f y0 u( t1 a, m8 f
set phase 04 G/ R; ^+ m' |! O( a; z( ?2 R
set num-cars-stopped 0* j9 w- f6 C/ _) h6 Z
set grid-x-inc world-width / grid-size-x' w% u( T5 ?0 h$ \
set grid-y-inc world-height / grid-size-y
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" h# f9 @$ l0 z. ^# G! W' @ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
: ?# a c$ M3 ^ set acceleration 0.0994 L, t; @! b; v- Q& [
end9 S5 i& n! W' F j# j
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,- @% }6 \5 L2 ~! W4 n$ N
;; and initialize the traffic lights to one setting
# g8 }8 w" b3 B. d( ?' Dto setup-patches* o6 }) Q Q2 |& d% B
;; initialize the patch-owned variables and color the patches to a base-color9 m: |) Y+ u4 z. X
ask patches5 s+ X7 k6 G! @1 F& M+ r
[
$ q/ v; i( T: e# [ t9 P set intersection? false
, [3 w" [( ~* U6 `+ j: i { set auto? false X: c9 o7 I+ ~
set green-light-up? true! J1 s) R6 A! R0 B
set my-row -1( `8 X) x5 S( o. E/ ~% Q, Q
set my-column -1
# p# }: J g( Q- X( q set my-phase -1
! O& H% `, R. Z, R set pcolor brown + 32 ~+ m& H! [$ x9 S4 F
]
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1 j8 w; a9 L% j ;; initialize the global variables that hold patch agentsets/ R" t& u9 G a8 V% s7 y( a7 X
set roads patches with: q8 ~; b" A2 d0 m
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 b1 n6 G7 F- q) A5 {* |* Y7 R (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 K9 w$ q5 f, R3 A% z9 L4 r; c
set intersections roads with
2 M% Y6 G- s$ [' r [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
$ A2 E) j1 e. t6 s; _6 ~* { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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j L9 R o) O! |, _$ P r ask roads [ set pcolor white ]5 j7 _7 Y9 H4 i) _7 b7 I
setup-intersections
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# z! w# c* Q4 G- M; _( l- W其中定义道路的句子,如下所示,是什么意思啊?1 i8 L% o- ?1 T
set roads patches with2 m/ x0 g5 k; ^! |! X: d
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ `: p6 p% s0 D (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) @$ P. b7 H$ g$ l2 t" _ 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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