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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。
7 P( {: f8 y* h) E$ |netlogo自带的social science--traffic grid这一例子当中,
. i9 Q4 {3 L$ S3 Fglobals0 k9 j+ K2 ]0 Z1 g- I0 k5 K
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grid-x-inc ;; the amount of patches in between two roads in the x direction
/ a, ^9 T2 X$ T/ G% x4 ~ grid-y-inc ;; the amount of patches in between two roads in the y direction! u3 C5 t8 K) z" Z3 Y
acceleration ;; the constant that controls how much a car speeds up or slows down by if, G+ a0 w5 |2 A- ?$ p
;; it is to accelerate or decelerate4 t. r% Y$ U4 A0 L% f3 f/ e U# T( C
phase ;; keeps track of the phase" N; u! X6 k4 i$ V
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure& M$ t! a3 k- z5 \$ S3 W4 M) A7 s
current-light ;; the currently selected light; g) {& \( j0 J" X/ P q$ A
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;; patch agentsets
* t5 k; f- U6 g# u, I+ w intersections ;; agentset containing the patches that are intersections
7 ^' K3 e/ p, N* N j; ]. b0 e& ] roads ;; agentset containing the patches that are roads0 D8 E& g/ g1 x, k, d
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turtles-own6 ?. v" b8 }3 a% @, N% a) z! p2 X3 T7 w
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speed ;; the speed of the turtle6 H {" H9 z* g$ B
up-car? ;; true if the turtle moves downwards and false if it moves to the right- k8 }! x# ^ ^1 H
wait-time ;; the amount of time since the last time a turtle has moved; `# _3 j, O7 j
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! L8 j. O" }3 [( y# }. T; @7 qpatches-own6 S' m5 N; A7 P6 X# Y- T
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intersection? ;; true if the patch is at the intersection of two roads: u/ d" k" N. \" P% G. D% h; g
green-light-up? ;; true if the green light is above the intersection. otherwise, false.' p& r: _9 Q1 P% t; ^9 m8 @ X! N6 ^+ E3 ^
;; false for a non-intersection patches.5 J$ Z" Z4 W9 b* R, ?5 A
my-row ;; the row of the intersection counting from the upper left corner of the
3 j: y& A. i- ]( e+ B+ i) `) | ;; world. -1 for non-intersection patches.- w7 t! q7 C- i" `
my-column ;; the column of the intersection counting from the upper left corner of the6 w9 p/ B) T4 S) t; p# ~1 N. ?
;; world. -1 for non-intersection patches.
/ \0 z+ W$ N5 Y% S my-phase ;; the phase for the intersection. -1 for non-intersection patches.
8 _# T) j0 w) \4 B/ M: H1 b* _% I auto? ;; whether or not this intersection will switch automatically." p a1 ^ s F' H( C1 [
;; false for non-intersection patches.# ^" ]' H6 l% |3 ^( S) ?8 X
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;;;;;;;;;;;;;;;;;;;;;;+ J8 R+ q% {# s
;; Setup Procedures ;;# ]; D ^9 G& T" L2 Q7 R# j
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.# \6 t" P m% K: h r
;; Create num-cars of turtles if there are enough road patches for one turtle to4 k m) f) X! l7 T. f
;; be created per road patch. Set up the plots./ D6 P/ j- B" N: o: Y; y& ~
to setup- ?2 b4 s. V1 M# u9 ^
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;; First we ask the patches to draw themselves and set up a few variables
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make-current one-of intersections0 Z% _7 Z) J: B7 i; j. q% J
label-current- J" V3 _) k- l7 N+ [9 c% t# q5 I; r
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set-default-shape turtles "car"4 S( [$ u+ w+ q6 j* N4 l7 B; Z% L" P8 P
v* H3 G( D1 n: T if (num-cars > count roads), M% {4 e5 e Q2 s* u. `; J o
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6 r. A) o* K/ P/ @2 @ user-message (word "There are too many cars for the amount of ", w7 \# _' j) T% w) R) q
"road. Either increase the amount of roads "
8 g5 R9 O2 e4 m3 F# m+ Y, c "by increasing the GRID-SIZE-X or "
3 ]0 X: A/ z v/ k# k& H- j "GRID-SIZE-Y sliders, or decrease the "
: s' p4 N3 q7 B0 ~- M "number of cars by lowering the NUMBER slider.\n"
$ I" ]# @0 j$ n5 o( P' U "The setup has stopped.")
9 t$ H0 Z c E: p stop$ \0 ^! D' W; p, T, }
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color* P- U9 X" j7 I6 z1 h
crt num-cars: e8 m1 A' V+ U" O7 z# V
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" N' G% E9 A8 |5 l' Q$ u setup-cars l+ l$ m# C- R
set-car-color! \4 z4 l' ?" _% r! ?$ }+ ~3 B
record-data; v. \0 Z- o: r
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+ b+ U- Q, r* J& _% ]1 C/ d; y. g ;; give the turtles an initial speed
& p1 `# v( G- W7 [7 Z8 E( ^ ask turtles [ set-car-speed ]
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reset-ticks
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;; Initialize the global variables to appropriate values
; G q7 `4 ^$ l- A2 q. C6 j+ M! Oto setup-globals
* [3 z5 M7 G2 l, F% V, X0 D& N& g" e set current-light nobody ;; just for now, since there are no lights yet
. g/ y# L: Z K9 u7 x8 u set phase 06 x4 e- C" O; p2 J2 j5 [! G
set num-cars-stopped 05 ]+ ?! t3 w. \
set grid-x-inc world-width / grid-size-x, L: R# E3 k" t& `( M! L
set grid-y-inc world-height / grid-size-y+ f! J. r8 D8 ?- P, W3 q( g
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary6 f3 p/ a) S3 Z; c# W
set acceleration 0.099
1 k+ N; V! X& k/ E1 E/ cend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,5 p v' c6 q. ]! e
;; and initialize the traffic lights to one setting
8 F1 @/ A* B. ?9 Pto setup-patches" n, v, t. H/ j: B& W% J% o
;; initialize the patch-owned variables and color the patches to a base-color/ B/ I3 S' H5 O, D4 c9 t
ask patches7 x1 O5 L5 u- [# _
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set intersection? false
8 U. k! Q4 U- t% T, A3 \+ r set auto? false& m7 |; z+ y) n
set green-light-up? true
2 p' a) j; h7 P0 U" z; ~6 t ~ set my-row -1: @; J6 }3 z1 }9 A( Q, U% @
set my-column -19 l2 i4 ?, A* N8 s+ S( b4 F! I, Z
set my-phase -1% ]# J3 a, o8 e# Y: u
set pcolor brown + 3- A) o! T1 {2 v* Z
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9 R) k( o* `: P. k# M5 w ;; initialize the global variables that hold patch agentsets d5 ]8 K5 f W5 y* }$ i3 |
set roads patches with) ` A2 \+ o& s5 G6 K) g7 \" ~
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 G* |" }# h5 i- a
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 O2 n' D7 e& j( V) o7 X
set intersections roads with" B7 f/ Z0 _6 ~+ J4 X8 K% Q0 \
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
+ i- `' }/ e G2 ? (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]4 W3 @3 V9 g3 {9 P5 F0 ?
setup-intersections
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7 f" G% p/ T$ J' x/ ?* p7 u5 Y8 \其中定义道路的句子,如下所示,是什么意思啊?
7 `1 d H w, _ e0 G set roads patches with
. N! c; E O* \' \ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' n% K/ p) ^+ c
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]# g& c) ?: S. U* ]5 ?. b
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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