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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。
" J7 p' M5 w6 D2 H- }6 Q4 |netlogo自带的social science--traffic grid这一例子当中,/ N% E' t$ |0 G' _( [9 {
globals% M w5 Z; G0 D
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grid-x-inc ;; the amount of patches in between two roads in the x direction2 P5 l' U$ ^/ f; j; x% S; c
grid-y-inc ;; the amount of patches in between two roads in the y direction
1 x. ^4 J! z) y4 C: o+ y acceleration ;; the constant that controls how much a car speeds up or slows down by if
8 `9 N3 D5 l1 {4 x- I7 n ;; it is to accelerate or decelerate
8 p7 p' V" z5 F7 C! c5 t& h phase ;; keeps track of the phase$ M+ ?6 W: F/ }1 V% s
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure6 z* S) @' x) `
current-light ;; the currently selected light& q5 K- M* |9 J9 e: c
* c- M; e1 I! a8 h ;; patch agentsets
9 x7 b9 u1 D# w, \ intersections ;; agentset containing the patches that are intersections' K: Z* z7 h) M' p
roads ;; agentset containing the patches that are roads
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turtles-own. }$ Z% z( z: ?6 g
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speed ;; the speed of the turtle
5 P/ V, K; [6 L. Z+ W# L up-car? ;; true if the turtle moves downwards and false if it moves to the right
8 P3 T! F4 u, h wait-time ;; the amount of time since the last time a turtle has moved
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/ i& `9 |! g: K$ e) V* Npatches-own
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( p1 l$ {2 c6 ?3 m intersection? ;; true if the patch is at the intersection of two roads2 J. F% j* K, T4 y* B% c! X
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
. T# p: c+ {. A& U' n7 I4 g3 M ;; false for a non-intersection patches.
/ }- J/ _, E; d# m8 p my-row ;; the row of the intersection counting from the upper left corner of the
/ @4 ~. H- A& H( y# ^ ;; world. -1 for non-intersection patches.( C$ l" p6 Z2 f6 U/ }) ~( u( O
my-column ;; the column of the intersection counting from the upper left corner of the
0 E3 F, I$ q! B- I( g7 \# T ;; world. -1 for non-intersection patches.
9 \8 L2 k6 r \/ \# {. V( M0 M+ c+ E my-phase ;; the phase for the intersection. -1 for non-intersection patches.0 h1 W8 G% i7 f, Q/ |- }: w( z
auto? ;; whether or not this intersection will switch automatically.' k: c2 w2 s( O* M' I" r" O
;; false for non-intersection patches.
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/ X" K* B! y4 R8 q- V;;;;;;;;;;;;;;;;;;;;;;
C: G- X6 e' d;; Setup Procedures ;;: N! ~. x$ ?% G; |! y6 [
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;; Initialize the display by giving the global and patch variables initial values.
% V" y1 E" [, f;; Create num-cars of turtles if there are enough road patches for one turtle to
r, R& p! }6 f( ~: i;; be created per road patch. Set up the plots.
8 N+ _: c* Z4 Z3 S3 { ^to setup
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2 f6 q/ C: ]6 O0 T! { setup-globals- I- M2 N) G# J2 }" ^
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;; First we ask the patches to draw themselves and set up a few variables
N8 u6 h' c6 v& v* X: [, Z7 p setup-patches5 p- y. O+ g- L* G! R! |
make-current one-of intersections
* P! c5 z/ F& L6 L0 K1 S7 C label-current3 ^. ~; I1 ?0 o+ L$ W6 h" X3 k
# D( v, k/ z$ H8 \3 ? ^; q0 d set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "/ }$ w- H( M1 z$ i8 F3 H
"road. Either increase the amount of roads "2 }1 n8 Y& j [* L9 n
"by increasing the GRID-SIZE-X or "
0 O5 |' M3 w4 V+ v2 U8 @ "GRID-SIZE-Y sliders, or decrease the "
# O% w/ r4 B o; A* w& g) \ "number of cars by lowering the NUMBER slider.\n"
& l7 d$ ?. M5 L: X "The setup has stopped.")4 O+ Y+ M5 g, p; A
stop, S# j9 ^9 `9 s0 F2 c
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color/ f4 D" }7 V0 z" O* ^/ U
crt num-cars% C& {3 L( r: \1 l! g$ O
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setup-cars
1 w( W* d* I: E! | set-car-color
5 g+ [6 U0 Q$ z- Q4 m record-data
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;; give the turtles an initial speed0 S! x8 M- B' [. w8 M
ask turtles [ set-car-speed ]
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reset-ticks* N" u. j; z5 h- l; ]- g
end
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+ m9 }8 Y% `0 o;; Initialize the global variables to appropriate values# ]: l3 {; V# U
to setup-globals
% C5 x" }" Q/ H# [ set current-light nobody ;; just for now, since there are no lights yet
2 w5 {& _$ Z1 d3 e set phase 0% ~: l% m& e" @5 t
set num-cars-stopped 0! n, b4 d1 U i! Z/ |" {$ x3 c' s
set grid-x-inc world-width / grid-size-x
" z8 d2 C6 ^. W/ C' y6 l set grid-y-inc world-height / grid-size-y
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( T# _0 H4 a2 y& H* s0 i ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary9 O% i$ L4 K! {- h: W) H! u
set acceleration 0.099: A/ d4 D8 I! A- d) u; i
end' s6 w Z/ f% K" W
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,6 R w6 {- |1 w6 i
;; and initialize the traffic lights to one setting
, E5 \ Q* Q* X" [& x& f$ ~to setup-patches! X" \7 _/ i( P
;; initialize the patch-owned variables and color the patches to a base-color/ \) Y5 }# z- B$ i: A5 \
ask patches
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) T V0 I8 Z" V. a, g set intersection? false
& _8 g& ^) ^' C7 u set auto? false
; s a2 _) q% y1 x+ J; ? set green-light-up? true7 h5 n! E1 F2 z0 N0 l! ?* J+ d
set my-row -1
7 Z+ L' z4 z4 H" F6 w set my-column -1
2 s' C0 F- t5 {/ U set my-phase -1# P- E3 ^. V& ~) g8 [7 x y
set pcolor brown + 36 m# |( o- d& _, B
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;; initialize the global variables that hold patch agentsets
- W: n8 N: w* m0 \2 W0 X set roads patches with
9 ]$ w% R: X1 J! N [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: n8 Y2 ]- Y) b8 w4 l" Z0 N: g9 H$ ~; D
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]" f ?6 K; ~( q2 R- y
set intersections roads with
. Q# i' ]4 u. a- g6 ^' U! O [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and0 {: E7 r$ ~% e3 F/ T. u6 R
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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/ N; i# h( z! G) E# s1 R ask roads [ set pcolor white ]
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+ y) M3 Q7 v& G& t3 qend) c( P1 |- k' R& m* s% J. b
其中定义道路的句子,如下所示,是什么意思啊?1 ^2 q- c/ d R# c0 d. [0 p- p
set roads patches with! o3 X, y( r0 k% f! W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 f/ q# y& z' N5 j2 w R. W (floor((pycor + max-pycor) mod grid-y-inc) = 0)]% a6 {8 N, E$ K/ H0 K/ R6 [
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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