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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。' j" O% f5 ^, ?, _
netlogo自带的social science--traffic grid这一例子当中,& `7 ?/ W! F! \. p0 F
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction6 M* s4 k- b+ |
grid-y-inc ;; the amount of patches in between two roads in the y direction
1 F7 n0 I9 J$ p6 m# h acceleration ;; the constant that controls how much a car speeds up or slows down by if, B: k$ R- }# P! Q6 V
;; it is to accelerate or decelerate
9 o6 x' H2 {* |0 `, K8 p phase ;; keeps track of the phase
9 M1 o/ ~0 N2 { num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
: o! [- G- u% i* o8 y% o current-light ;; the currently selected light
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+ r# c! U; e; ^% | ;; patch agentsets2 T$ N6 ?$ @0 x6 v q
intersections ;; agentset containing the patches that are intersections3 R0 {0 m) M# u% i7 O) G
roads ;; agentset containing the patches that are roads
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0 `: z# R: ?2 b/ R0 D' Eturtles-own; X$ s) B& U& W d3 K' O( ~/ T
[
* {7 ]2 v5 i2 e3 I. P speed ;; the speed of the turtle8 V0 _" i5 {4 E8 A; p
up-car? ;; true if the turtle moves downwards and false if it moves to the right, m/ W# |8 d# \$ _. d6 |
wait-time ;; the amount of time since the last time a turtle has moved
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0 H$ c( R; _6 D7 cpatches-own
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- x) `) j8 l/ z- p, [/ }( r! ] intersection? ;; true if the patch is at the intersection of two roads1 i- u) k" [) t* ~
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
; ^ ?* g7 l. L% i ;; false for a non-intersection patches.
* S0 {. J1 l/ H8 N' J2 |) E my-row ;; the row of the intersection counting from the upper left corner of the3 x* a2 D! u* B, F2 r3 @4 \6 h
;; world. -1 for non-intersection patches.0 V/ l; ?: G1 U2 ]& y9 s9 K+ m$ X
my-column ;; the column of the intersection counting from the upper left corner of the2 t5 I, ]6 J# G$ m* z
;; world. -1 for non-intersection patches.+ ]# `# X$ I* j# m& ]+ K! A
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
4 U, D" o% `9 N. P7 V9 t6 X: v auto? ;; whether or not this intersection will switch automatically.
) ^: K7 _' Z" a3 M5 ? ;; false for non-intersection patches.0 l% f* j8 O5 L- E; v
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;;;;;;;;;;;;;;;;;;;;;;$ O! c/ _# j; m o3 {
;; Setup Procedures ;;9 m, [6 m" o. t4 I3 M7 v' s& L
;;;;;;;;;;;;;;;;;;;;;;
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0 H- i' K# h- d;; Initialize the display by giving the global and patch variables initial values.
; r, t% I |: z% R' {, i K! k;; Create num-cars of turtles if there are enough road patches for one turtle to, V9 t" B8 O- @3 \
;; be created per road patch. Set up the plots.
5 z, |: R) y; z! `to setup6 b+ e1 b. c/ S3 l* O# D( n( c
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setup-globals, s9 D, ~" m; m6 d/ y# @5 |4 I
0 ]4 V4 b$ w! A* W7 ` ;; First we ask the patches to draw themselves and set up a few variables8 Q' M' V+ i" w# N- |- t
setup-patches
5 E; x( X4 m4 [ make-current one-of intersections4 f2 A+ n3 }) M, v
label-current
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set-default-shape turtles "car"( {- h3 k; i) G$ Z4 c
- ~6 S: \5 I; |9 _9 H* H- L. u if (num-cars > count roads)
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C! I! }) p" o; z' `: T3 q A user-message (word "There are too many cars for the amount of "
) {: ]* c* i, A# z8 j "road. Either increase the amount of roads "
6 J S: F8 v# P6 p "by increasing the GRID-SIZE-X or "
( e% g7 @1 K2 [5 s! a. ~ I( d5 r "GRID-SIZE-Y sliders, or decrease the "- J$ V( U5 J) I' \6 {( u- n. f% i
"number of cars by lowering the NUMBER slider.\n"
1 ~. t( j9 y: x- d4 S# }& m "The setup has stopped.")
C. a; K# B" J; J/ S8 m( b stop# }4 P( n! r2 ?: p- h9 g
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color0 }" x% M$ _; W9 Q
crt num-cars- w6 _9 [" W* O$ S$ e
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setup-cars5 P' F1 T5 p4 O4 D+ m
set-car-color
7 O3 w& l6 h, X+ f8 E) c record-data
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;; give the turtles an initial speed
7 K1 @( a! t" ~9 ~; w ask turtles [ set-car-speed ], c2 N7 c3 z4 i
4 G/ B4 Q. [( u reset-ticks
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$ B: B" j3 z, L, V, v" R6 Q;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
8 B: K) { K: T2 g, f s' d set phase 0
, N8 Y/ f0 p) r' z3 C set num-cars-stopped 0
. J: Z7 Y& r+ d- D# G. j3 ^ set grid-x-inc world-width / grid-size-x- m1 w5 g, i! y$ ]
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary$ i2 H$ w8 v0 R* K, Z5 v
set acceleration 0.099
1 t; D, G4 L7 l; Eend
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( P( g; I0 Z" t- ]# J;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
9 P( g# _, F; ^6 ]1 E/ J;; and initialize the traffic lights to one setting
( o' V! i4 x1 R* U/ D4 f, `/ `to setup-patches2 Z0 X5 ?# e2 I0 e. x! ] T
;; initialize the patch-owned variables and color the patches to a base-color) p P: B* W3 p% S5 u$ N' ~
ask patches
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" y1 A4 }' N6 \ X C set intersection? false! {2 r6 f/ J& g* X
set auto? false) G0 i- @5 w, K
set green-light-up? true/ j7 I5 e1 t. D$ q% _5 }
set my-row -1
( q; ~2 H0 {1 w$ t set my-column -1
& i& ~ Q8 X% f( w. }/ B1 s2 ] set my-phase -1
: z+ R5 B8 g( A) W/ W; c( B set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
0 J+ ?( J$ f+ r" h% I set roads patches with! a! t/ C# f0 ?5 Z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: e+ @4 D5 E0 R3 |$ N+ Z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; k# p7 y2 A% R, C) R5 K/ I5 |. }# H set intersections roads with% D1 e3 X* ^9 v2 y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and6 @& m7 S2 o: S! y) j, n7 V3 T1 k T1 m
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]3 z3 N/ u, l8 z4 B
setup-intersections t! b" j) E2 B) d6 Q/ U9 |# O/ V
end$ ` r7 E+ I6 s2 f; f( [2 U$ S
其中定义道路的句子,如下所示,是什么意思啊?0 [- s: V( g* o' |/ b) R3 P
set roads patches with6 x) Y) u1 T. p1 e, h% g0 Q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 D1 q& K! }9 l/ x7 e& w (floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 [7 D) b4 |8 ~1 i$ {
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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