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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。) t' n4 G8 M, [# X
netlogo自带的social science--traffic grid这一例子当中,# |) Q5 z+ T) S. f8 @. j' L
globals
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: G8 T2 O3 K7 H0 V grid-x-inc ;; the amount of patches in between two roads in the x direction, T3 v- F- @# Z8 Y
grid-y-inc ;; the amount of patches in between two roads in the y direction
) M" e, F8 V1 ~: B! e# E, q acceleration ;; the constant that controls how much a car speeds up or slows down by if
8 H: N3 k: [$ i; ~ ;; it is to accelerate or decelerate: ~ E! U9 @0 x( s+ F6 Q+ y x
phase ;; keeps track of the phase
$ i% T, u% o, b" X num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
# f1 J& S. u& n S2 L9 d3 b current-light ;; the currently selected light
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;; patch agentsets+ h! k. f: f4 N
intersections ;; agentset containing the patches that are intersections$ Q% y! O6 ~5 w# Q- V4 F
roads ;; agentset containing the patches that are roads
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; j% W, ~7 K! t4 V/ I7 I% fturtles-own. n2 H3 {- u U# V9 x
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7 A3 X+ n$ a2 l2 O7 B speed ;; the speed of the turtle
! O- h+ h: Z0 j2 T2 k9 Q up-car? ;; true if the turtle moves downwards and false if it moves to the right
2 T# o! p$ J+ R5 R7 Y4 J: S3 N wait-time ;; the amount of time since the last time a turtle has moved
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patches-own/ g- r% A I/ U8 ^! v" G# K6 C% d
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* ]- X/ W: H6 H; Q intersection? ;; true if the patch is at the intersection of two roads
" j+ F2 z [7 i B* R green-light-up? ;; true if the green light is above the intersection. otherwise, false.
# X) \9 Z. S8 M/ P; N. s6 e ;; false for a non-intersection patches.; e/ @9 h6 o, {# I. ?
my-row ;; the row of the intersection counting from the upper left corner of the
5 S4 ?7 |/ T" `/ P8 j4 J/ O ;; world. -1 for non-intersection patches.
! G. K5 [( ~& M% Z my-column ;; the column of the intersection counting from the upper left corner of the
- f9 K2 ~0 y7 @ ;; world. -1 for non-intersection patches.
, O9 B4 l9 s! H2 {% S my-phase ;; the phase for the intersection. -1 for non-intersection patches.
& U, x( {0 Q% X0 W1 j, R0 W) P' \ auto? ;; whether or not this intersection will switch automatically.
: n. r% G; E& }$ O. R2 i1 X, S ;; false for non-intersection patches.
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1 u, y! B2 s& {! O3 r. L4 u;;;;;;;;;;;;;;;;;;;;;;- m: W; P4 g9 S% E$ B
;; Setup Procedures ;;
* B$ s& ?; U" D. ]7 N;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
+ ~6 C5 e- F5 k1 ?/ a: ?$ Y;; Create num-cars of turtles if there are enough road patches for one turtle to3 f% G5 X4 A4 v; T) F( @
;; be created per road patch. Set up the plots.
o3 f& n! D- H/ K/ n/ b. Gto setup) u" ~/ ~) w2 ]
ca
+ K: F4 C- U- | H/ h) w% H7 ] setup-globals* B- M) n. h, u' B) f; ?( o
! W$ b4 H Y6 \9 r! [ ;; First we ask the patches to draw themselves and set up a few variables/ {- G3 h- C: K# [4 C7 Z/ K
setup-patches" }1 R: D- o, ^3 [
make-current one-of intersections D; G0 ?! f$ o7 v, S
label-current1 K4 a7 U$ Q8 R4 {" c# m
5 `/ z* B7 K% j K5 S: v _ set-default-shape turtles "car"
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if (num-cars > count roads)
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; b! x9 p& U3 s: x. `/ _# V+ {6 d user-message (word "There are too many cars for the amount of "
* M$ V6 E' y1 X X "road. Either increase the amount of roads "% G. Q. u% M Y; |9 u* v
"by increasing the GRID-SIZE-X or "
( A0 x: u ?( G) H! W* H8 J9 P "GRID-SIZE-Y sliders, or decrease the ") f$ M7 e* M+ c- E. m
"number of cars by lowering the NUMBER slider.\n": k. s" M3 m1 s6 h* [
"The setup has stopped.")
% W3 B3 g5 F& T/ S& z% [3 A+ v stop
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) _ W6 U4 n5 @; V+ Q ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color* _& P/ t |4 q( p( N# w8 s
crt num-cars# O3 m4 O3 H j' m
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setup-cars) d% Q3 k7 h) ?- |" y- I5 `
set-car-color
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;; give the turtles an initial speed- u+ w1 X0 P2 H
ask turtles [ set-car-speed ]& {/ ?; y; O- p; }2 w
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reset-ticks
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9 ?4 M2 O0 ~& G* L1 _( s;; Initialize the global variables to appropriate values; N- n, \) z+ |( i. Q
to setup-globals
, J$ b9 O- T1 F8 f: e* d set current-light nobody ;; just for now, since there are no lights yet _/ s2 H; M" X( a+ U
set phase 0
U+ S: A. k: ` set num-cars-stopped 0
5 S8 T% G8 I2 Q1 L% s- ^% k set grid-x-inc world-width / grid-size-x4 z0 F$ V. d) Z" E# k# Y5 @/ g
set grid-y-inc world-height / grid-size-y
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% A6 V; m `. T' S! c ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
& q G2 N5 V4 R9 x( Q$ f* p% ~ set acceleration 0.0994 H1 e4 k! z. b. W2 J$ M
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
& q r5 f# e2 n8 \;; and initialize the traffic lights to one setting
- m* M: R9 e4 oto setup-patches
# |: l( C3 r- L+ b/ Y' Y) E# b ;; initialize the patch-owned variables and color the patches to a base-color* L0 | V: K. N6 h
ask patches; r6 V- }7 q5 a/ H! `# m" |
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. w$ p! n* w- P/ j7 c0 ?/ r set intersection? false
3 h3 A8 n/ Y( Y0 f7 } set auto? false/ ^1 \7 G4 P& f
set green-light-up? true1 v' e. F- r" X! p% E
set my-row -1
4 m6 d5 R: L3 n: D- r set my-column -1
+ I6 m8 l5 z/ s# k1 n set my-phase -1
+ |0 W- @; i8 \3 [( C set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets+ b/ B( I% ] ~4 |
set roads patches with x& p5 k5 A+ J! w3 A) |. W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- M1 D, F9 p. ]$ [- d/ t
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
f/ g3 |$ E0 {) ~+ ^4 M set intersections roads with
* i" r; u4 x/ G8 O+ X0 n% M. _' D [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
, A' u& ?* j2 B! n3 ` (floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 o8 z# c& F6 s* Z5 x
; L5 l4 q% s C ask roads [ set pcolor white ] O% E9 f; A. V6 D2 b9 g, I
setup-intersections# J- E/ c A6 P' C2 q
end
( e; `* t a1 ~9 `8 {" j4 @其中定义道路的句子,如下所示,是什么意思啊?
( f5 W3 i' V! l1 H set roads patches with
3 p5 t0 _9 p" }4 _) e5 z$ d, T. s$ o9 t [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" f Q0 ]! k! {' d M2 C
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. `7 h3 I& \: C$ ^" a6 C; c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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