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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。0 D/ r+ a& W+ Y5 V- l: S6 ?
netlogo自带的social science--traffic grid这一例子当中,
1 o+ B$ M5 H$ ]- h5 F$ dglobals4 ~( [6 ^3 E, |. o+ X: g+ {3 Q
[
* m; Q( f: g+ N0 N6 w. _1 T1 f% z grid-x-inc ;; the amount of patches in between two roads in the x direction
5 v1 D; ]' r, q: s2 v: B) ] grid-y-inc ;; the amount of patches in between two roads in the y direction
. Y$ p" K. R( a( r acceleration ;; the constant that controls how much a car speeds up or slows down by if$ e# b5 v4 `; S7 t, x- r; \4 d
;; it is to accelerate or decelerate! y# g" v8 j1 t, k
phase ;; keeps track of the phase
" y0 e: a7 ?! p) d2 U, e4 a5 | num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
8 P5 o0 i' {7 v- s$ E current-light ;; the currently selected light
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/ f- W4 ^2 n& A( U- C6 g ;; patch agentsets
; I3 x2 G+ Q, X1 P% T0 s' e9 X: P intersections ;; agentset containing the patches that are intersections' C4 q; c4 [9 A4 ?
roads ;; agentset containing the patches that are roads: ^; ]$ l7 a% ]$ Y B
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! U$ O, T' Q+ j" r7 Hturtles-own: U0 K# r# ?9 ]' o) z& |
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speed ;; the speed of the turtle
6 O7 ?* P2 d, M4 u+ u up-car? ;; true if the turtle moves downwards and false if it moves to the right
( P( c; _8 u. N1 s wait-time ;; the amount of time since the last time a turtle has moved
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patches-own' c9 Q. d9 R4 r! E) t
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intersection? ;; true if the patch is at the intersection of two roads0 J6 `" b6 [ @8 a. ]; w u
green-light-up? ;; true if the green light is above the intersection. otherwise, false.+ V& W1 \8 W/ P1 P) n2 T* y6 C
;; false for a non-intersection patches.
. E# T& }' z4 X$ g3 X' _1 F my-row ;; the row of the intersection counting from the upper left corner of the
, T* H& N8 K9 j ;; world. -1 for non-intersection patches.
8 o) c8 p+ ]' |- M my-column ;; the column of the intersection counting from the upper left corner of the
8 n, M; D3 W, A5 C4 k ;; world. -1 for non-intersection patches.
8 ~9 |/ ^: X, W! y' l* A) M- i5 n my-phase ;; the phase for the intersection. -1 for non-intersection patches.3 q* e1 u3 s. H+ T; K8 I( |" L
auto? ;; whether or not this intersection will switch automatically.1 \2 a$ Z. h) b1 r: f, U( ?6 ?+ p3 u' d
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
: h. i7 ]8 y$ e$ ]2 t;; Setup Procedures ;;- Q0 }# o* c: w$ k R
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.6 Q; `! o8 F7 Q% S0 Y( X
;; Create num-cars of turtles if there are enough road patches for one turtle to& \, g3 V j" r) Q
;; be created per road patch. Set up the plots.
- y; ?0 y0 L* f# b% Z* L( kto setup
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! n& B3 \8 ?2 j6 B setup-globals
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;; First we ask the patches to draw themselves and set up a few variables" A# z- B: h* k. s1 _: G0 @
setup-patches
4 u8 B& L P( i0 u. i make-current one-of intersections: y. K1 e$ I5 F! M
label-current2 i4 W$ J2 ?3 p+ V o
% b* C {0 K8 g+ d set-default-shape turtles "car"
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7 |/ W, \. `6 Z0 _5 |$ B* Y% B if (num-cars > count roads): F8 v# t1 R) R; g- S) V u4 a
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. v. I) M/ r4 i. ` user-message (word "There are too many cars for the amount of "8 w$ s0 A* v5 n& @/ f. m5 R
"road. Either increase the amount of roads "
& i, b, w- }- ~, l) { "by increasing the GRID-SIZE-X or "" Z' U4 }5 |$ B& [ Y# c6 {( ~
"GRID-SIZE-Y sliders, or decrease the "
" S7 _* ?8 \- y2 w "number of cars by lowering the NUMBER slider.\n"
& s9 z) d% a4 m; h/ H "The setup has stopped.")# X+ g7 M8 C" a- U T3 P- R2 W
stop
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- N& Q0 X* U# M% J4 Q ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
7 L$ B! |* p3 V7 w$ n crt num-cars
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, @2 E. `7 [3 [& D setup-cars4 E4 n- ~0 o- \& H$ E$ X
set-car-color
0 F3 |! F2 l# ?6 L record-data) a4 v( I1 M! m. H! }% n' h
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0 b4 H6 l( j5 [3 B ;; give the turtles an initial speed5 ^5 S, Y; ?/ K8 f' V( s! t F! C
ask turtles [ set-car-speed ]
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reset-ticks- B) J, ~3 H) w/ {; _/ A
end' J. f- P: z! V y* s4 J
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;; Initialize the global variables to appropriate values
' E" j2 Q& ~5 j2 a6 Oto setup-globals
) P9 B6 i) b' f7 g* ?4 C/ e set current-light nobody ;; just for now, since there are no lights yet
" r9 F8 ?2 S; T9 r5 ~ set phase 01 l t6 S. X% |" G. {
set num-cars-stopped 0# K& |8 T7 h9 W1 k2 M9 N
set grid-x-inc world-width / grid-size-x
; V: s6 S) ^: Z( I# g- S# J% I set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
! ~7 w) h; H9 U; K set acceleration 0.0996 {' ~" t+ d6 ^4 N8 h2 _
end2 E1 }/ Y1 ~+ F* k: m
2 _. o: z4 f% r/ u;; Make the patches have appropriate colors, set up the roads and intersections agentsets,: p I9 E# a4 l% z
;; and initialize the traffic lights to one setting' {8 p" E* y; {' ]+ }
to setup-patches
/ @3 ?! b3 b8 m0 s* S ;; initialize the patch-owned variables and color the patches to a base-color
: j' D. L( _/ T# k1 Z ask patches. J& `2 y3 Q$ Z1 | W( H
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- c+ O s7 p2 K) z- V/ ]4 v set intersection? false2 q/ |% e, ]8 T: Q5 Y9 Z
set auto? false7 c: B# {: x" F, y7 D$ @
set green-light-up? true% U# a+ K+ `* Y# m5 A
set my-row -1% N% u& P) U; w& V6 c
set my-column -14 A& \( X& n9 X( w$ O
set my-phase -12 h* J; z7 C9 \
set pcolor brown + 3, q4 _ k/ M* T$ e2 Z
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;; initialize the global variables that hold patch agentsets- x) [4 X7 i, f7 @. J
set roads patches with* }( `3 Y/ V0 F/ L2 [
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! Z' K: X: _/ {( f
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ ^# v2 P! [! q% P" D% w set intersections roads with
: s5 J. `+ |% e) x2 q+ Q- [* @. L [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
& F7 w! G$ q; u# U2 T (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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: v+ h+ O# A/ g# s1 }6 }0 y) I ask roads [ set pcolor white ], @0 G+ z; q9 N
setup-intersections J6 H; f- Z# C5 m1 c
end) [2 Z: R& v8 B5 ~
其中定义道路的句子,如下所示,是什么意思啊?0 Q% N9 _9 c) E$ X
set roads patches with
, z# P' Y/ Y1 b$ f1 U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ e( P S; W+ m% W W( W (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# `4 H" S1 v5 G u6 W$ L: W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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