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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。! W c# d) v# D
netlogo自带的social science--traffic grid这一例子当中,
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grid-x-inc ;; the amount of patches in between two roads in the x direction
j: [2 j' t, p$ A' j7 d- u2 x6 ~ grid-y-inc ;; the amount of patches in between two roads in the y direction
3 a& p' f. t: y% ^. Y# J, _ acceleration ;; the constant that controls how much a car speeds up or slows down by if
% \* X5 q) f, Z ;; it is to accelerate or decelerate
& z" X/ b. I8 L! }" l; j! b) J phase ;; keeps track of the phase0 Q( w4 F' l3 V# T6 M
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure' t0 `' a! H9 E; b
current-light ;; the currently selected light: r" ], w, o7 ~) r
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;; patch agentsets
( |% m+ [9 @3 w intersections ;; agentset containing the patches that are intersections
) l; W {8 O- M5 `, X! W9 F+ d- L4 @ roads ;; agentset containing the patches that are roads" C5 m$ {; @9 L% O) r, \8 T' d
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turtles-own
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speed ;; the speed of the turtle" S# P( p2 @. N( H" @8 j9 n
up-car? ;; true if the turtle moves downwards and false if it moves to the right2 k: O+ D: @% F
wait-time ;; the amount of time since the last time a turtle has moved
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( l* ]* ^) p6 R1 rpatches-own
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, g% z3 Q0 c/ U' H! B intersection? ;; true if the patch is at the intersection of two roads
3 C; K, E5 p4 ? q* g' x+ H green-light-up? ;; true if the green light is above the intersection. otherwise, false.4 s7 h7 E, [7 H% p' v6 @
;; false for a non-intersection patches.9 h& o' d" i) m% P# Q i: s
my-row ;; the row of the intersection counting from the upper left corner of the) r0 _8 f# f1 h8 @, L3 V
;; world. -1 for non-intersection patches.) A4 A! t/ ]5 a, e7 ~/ x+ B
my-column ;; the column of the intersection counting from the upper left corner of the7 i- a1 N1 {7 ?' _2 r
;; world. -1 for non-intersection patches.
/ m$ X& f; X8 K j b my-phase ;; the phase for the intersection. -1 for non-intersection patches.% H: J- V) b t
auto? ;; whether or not this intersection will switch automatically.* _$ U: V- T' ?, h; S
;; false for non-intersection patches." q5 ~: s+ [" j9 f9 N# |5 k4 i i
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;;;;;;;;;;;;;;;;;;;;;;5 i9 C1 B. K V6 p8 M, K
;; Setup Procedures ;;2 e7 I$ [% g1 a
;;;;;;;;;;;;;;;;;;;;;;, c4 W. w" C+ N* p5 l
8 E7 f3 a. o7 e' y; T;; Initialize the display by giving the global and patch variables initial values.$ u; }5 K: E- t3 B, x# d, E; ~
;; Create num-cars of turtles if there are enough road patches for one turtle to
1 M7 U& R6 | P) ?* U$ N$ @' v;; be created per road patch. Set up the plots.
4 I& M! a) @& u0 R+ Jto setup5 J; i) y" b7 S! S& K: q& h0 m
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setup-globals9 Y5 |$ L5 e/ {& q$ e
1 }9 P, B3 }4 N4 [4 \7 V) ]( a ;; First we ask the patches to draw themselves and set up a few variables/ q) O# j( O. n# t$ c
setup-patches7 x, |3 G1 D, b/ Q
make-current one-of intersections3 p# @& x x4 Y1 \( g
label-current
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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 "
- U5 }+ n' V4 C$ s. X: @; ~ "road. Either increase the amount of roads "
5 X& K* G6 d. P$ t "by increasing the GRID-SIZE-X or "
$ G* Z; v! u8 v C "GRID-SIZE-Y sliders, or decrease the "# E+ W" L/ q1 o) V+ q9 y
"number of cars by lowering the NUMBER slider.\n"
- z0 L P3 ^9 N "The setup has stopped.")) ^: E$ Y7 z+ t7 X& C3 T
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color. J. N F1 c, S. E% O" n
crt num-cars
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( W1 [9 s6 M" o8 K setup-cars3 z- m3 O+ c3 c7 ^! D& N: V
set-car-color
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$ Q0 t! c: N$ g3 J9 r' c2 z" I ;; give the turtles an initial speed
2 f( b5 L) i0 a/ |/ p ask turtles [ set-car-speed ]
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reset-ticks
" N$ I( [6 S. p5 C! I) ?" Lend
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3 v8 u; ], t1 U% B) K' {;; Initialize the global variables to appropriate values
5 Z: n0 q6 T: L- T" s- e; M$ \to setup-globals
; ?. U; u8 p: k+ g' O/ [! G! I set current-light nobody ;; just for now, since there are no lights yet- @% J; W6 p. X1 B5 }3 e
set phase 0
9 L1 O" F( a$ c( l& s- S5 S' h" G set num-cars-stopped 00 o9 S" o8 m% E: T3 a" q' y3 D
set grid-x-inc world-width / grid-size-x; Q6 Z( V3 X# e4 g
set grid-y-inc world-height / grid-size-y2 T$ C& N# k, m) A; F' @( _
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary5 `: m2 _% u+ M+ ~
set acceleration 0.099
" N% P' @% x: ~7 ]. `) Dend! e0 G# Q2 ]% Q. u: [/ {
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
# M) n# f- q! W( B;; and initialize the traffic lights to one setting
4 _8 u2 U# C$ X& N2 Ato setup-patches8 E4 [3 q- X1 Y3 J0 ?
;; initialize the patch-owned variables and color the patches to a base-color' v U! x" s7 r, R" H
ask patches
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set intersection? false9 N9 _ s1 f. K2 L |: `
set auto? false
& |- w' A; m' x. i: d4 s/ J6 ~ set green-light-up? true
. q: `. g8 Q) S8 g5 m set my-row -1( p) g/ Z! ~) ~) [* `7 _5 Z& H
set my-column -1. i9 [# C2 G3 L
set my-phase -1
& D6 e$ A/ S) h( e) O$ B5 ^0 j0 A set pcolor brown + 39 w) P/ [# U. f7 S$ u1 l
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+ k# C9 g* \1 N* S* c( [ ;; initialize the global variables that hold patch agentsets! b; ^7 ~- \$ F+ B4 r3 g
set roads patches with! [# ~8 D* M6 [- Y6 e
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
v6 Q8 s* g* G (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 ]4 G) U+ [9 D
set intersections roads with/ t( o8 v, O8 ^2 T0 ]3 x# P' i- r
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and: N7 ^9 W# p' U# O) t2 A6 M8 Z0 ^+ I
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]: O" x/ Y, n& k* a5 z2 k
setup-intersections9 B( B4 w. B$ }# w2 q5 w
end4 k4 b. E2 J* o2 Z
其中定义道路的句子,如下所示,是什么意思啊?
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6 e; H1 j4 I" p8 w. u/ U# d [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ q" ]) t9 T- w# e* ~5 b
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]- t0 N3 p) V: t
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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