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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。3 D6 J% R6 M" V* ]( O
netlogo自带的social science--traffic grid这一例子当中,
' a3 Z7 b$ ~& j6 \globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
T4 W% C( I u3 v: } grid-y-inc ;; the amount of patches in between two roads in the y direction% d" j1 J" _; I- {& ^
acceleration ;; the constant that controls how much a car speeds up or slows down by if
- X9 o3 A2 ~0 e6 _. E2 S; K7 | ;; it is to accelerate or decelerate
6 Z0 ^6 M3 P# \* B% p4 y3 U3 e5 }) C phase ;; keeps track of the phase
0 @# ]0 ^3 w+ g5 A7 J& `1 } num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure+ n, x" y" H4 P& `0 J
current-light ;; the currently selected light
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* A; {0 a- L$ Q* I8 R# Y ;; patch agentsets0 r K, a, p* j9 e- [4 i* Y
intersections ;; agentset containing the patches that are intersections
& r2 V* h8 ?# x& G4 M" K roads ;; agentset containing the patches that are roads, n! [4 l6 [" v# x
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turtles-own
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speed ;; the speed of the turtle: J( Q* U# d% W$ z$ i* Y! m, T% \
up-car? ;; true if the turtle moves downwards and false if it moves to the right- ^! i8 F6 k t
wait-time ;; the amount of time since the last time a turtle has moved7 S- Q/ C$ m. d
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patches-own
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& a' w: A1 s" U! v! P intersection? ;; true if the patch is at the intersection of two roads
+ r( }+ x% H- K/ W2 ] green-light-up? ;; true if the green light is above the intersection. otherwise, false.
" ~ ], P% w& d1 \# k ;; false for a non-intersection patches.# R! K% Y. L6 V7 n; o8 ~2 z
my-row ;; the row of the intersection counting from the upper left corner of the! j+ F9 y5 K2 }$ v( n
;; world. -1 for non-intersection patches.
' F1 ]# f m$ i2 L E- J2 n my-column ;; the column of the intersection counting from the upper left corner of the# [; i- F5 K+ }/ p' V. E9 I
;; world. -1 for non-intersection patches.
6 L; U0 s+ L. [) q8 g: W6 I my-phase ;; the phase for the intersection. -1 for non-intersection patches.
0 a5 P0 ?+ t* {+ [3 x auto? ;; whether or not this intersection will switch automatically.% u8 \9 w$ I h3 s
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;6 b( N4 J* P( g6 `3 j; Y3 w
;; Setup Procedures ;;7 h; B/ A) D* B6 x* z2 U' S1 Q1 _
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.4 ^7 T7 A5 {4 q( t! O
;; Create num-cars of turtles if there are enough road patches for one turtle to( N* r( ^# ?4 }- ^& {& N, h! q
;; be created per road patch. Set up the plots.
( @ _( W) M& {to setup8 N9 `. f$ y# [8 R
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setup-globals% @! S5 Z, i% k) S( @# U7 Y: M
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;; First we ask the patches to draw themselves and set up a few variables5 ?9 n* j2 Q" N+ Y1 N. L) {
setup-patches% V( J# c/ L n2 E0 T) h7 h5 I
make-current one-of intersections9 ?6 w* P+ i2 r$ y6 r2 X' N
label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)& V- K0 ^/ C9 w @4 W& C/ h' O
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user-message (word "There are too many cars for the amount of "; ?2 o+ F* r# x9 G! ^; j
"road. Either increase the amount of roads "& z9 [* N1 u% T2 s" @
"by increasing the GRID-SIZE-X or "( |' F d a3 m# V" `2 E. [5 Y/ T
"GRID-SIZE-Y sliders, or decrease the "2 b) A4 w3 a& N+ `6 Y
"number of cars by lowering the NUMBER slider.\n"$ l0 {8 n) g7 t% k3 j! [1 e
"The setup has stopped.")% P" g$ i1 z: \8 o% q- x) `
stop
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% Y- a+ [; Z2 C x2 b( f ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color# p W6 }9 d2 G# J# H
crt num-cars( F, N+ q* _9 G. a2 t/ Y Y; W
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( b w& T3 g( g- b( k5 X: u' _7 |5 w setup-cars
' ?' u$ A* r! u7 Q3 @1 K5 d set-car-color
# a+ ^! p& U+ k; v- k8 s3 N0 c record-data
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- [, v4 W. u, Z8 Z9 I# X ;; give the turtles an initial speed5 @+ _/ I% J4 `) F v+ a
ask turtles [ set-car-speed ]) S6 h/ W b' |' ^' e
# q# u% ]& a. n$ J( Y$ q1 d reset-ticks2 v9 Y, @/ k: D
end: Y0 Y0 U5 U$ y
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;; Initialize the global variables to appropriate values6 {% `; f/ ^0 o/ ]; j0 _/ X
to setup-globals1 I- Q! |' y6 P# T' _
set current-light nobody ;; just for now, since there are no lights yet
! b/ k s& ?9 j1 k set phase 09 T+ m# M1 M+ D
set num-cars-stopped 07 u) c8 r# ` p3 |+ N7 q
set grid-x-inc world-width / grid-size-x/ W1 {. F" p+ w- Z: o
set grid-y-inc world-height / grid-size-y# T) v, v o! F
3 h3 p7 |# \1 L ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary& |' A8 a7 {. {, I( v
set acceleration 0.099
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' U# A6 G6 u6 E. B' j! V/ };; Make the patches have appropriate colors, set up the roads and intersections agentsets,) |! Z- q, m) U; P, b. J1 r' X
;; and initialize the traffic lights to one setting
8 \! N4 c; Y; K* i8 ato setup-patches
7 e6 n, a& j% t5 r1 Q( N ;; initialize the patch-owned variables and color the patches to a base-color
, F/ ~: P4 ?& Y* A ^ ask patches" |0 b3 Y& D% e" i8 \0 j0 G$ g
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set intersection? false6 F# x6 I/ m' G1 i- {/ R4 g9 ?
set auto? false
/ i: z, C. Z* s a7 C h3 R9 [ set green-light-up? true/ g. |- ?, e$ h/ G; _9 k& b* k+ g$ c8 ]
set my-row -18 H' v8 E( V" z; P/ m
set my-column -1
& }8 e) { K! n4 u2 d2 U( H set my-phase -1
# U! R4 E G( { set pcolor brown + 3$ J& N! G* C, n
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;; initialize the global variables that hold patch agentsets
) P! N8 M U( c2 \( }- L, ^9 B4 e( ` set roads patches with% c2 Q, \8 S# ^9 F' N$ B9 h! n! x
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# B7 y; k1 C0 w! ^" E% H! a (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% |* X: w7 {( q: p2 i8 o/ _4 f set intersections roads with. i. K: W4 s% A ^
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
1 n# C! Y" d4 V X8 k* \ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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end
1 `" q' `6 L6 V1 X: Y: }; r其中定义道路的句子,如下所示,是什么意思啊?
. F& I1 H$ z# E" s set roads patches with3 ]- D; U- J% C& q6 U& C F: e6 s
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ `3 A0 k! j& D (floor((pycor + max-pycor) mod grid-y-inc) = 0)]! n7 D% A1 D8 O. b% m0 _$ i2 y
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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