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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。
# P- Q3 r5 J+ ]- A5 znetlogo自带的social science--traffic grid这一例子当中,! P' I. q4 O. y; Y: T
globals2 m [; A4 L, ]& M2 n1 {
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grid-x-inc ;; the amount of patches in between two roads in the x direction
9 [* H4 u, g& T grid-y-inc ;; the amount of patches in between two roads in the y direction
3 ~0 [" ]0 j) d! S5 N9 m acceleration ;; the constant that controls how much a car speeds up or slows down by if! v1 Y5 {$ U- H5 b" p4 S. {# b9 W
;; it is to accelerate or decelerate
) T3 _7 ], L2 a2 ~) G# q8 _7 Q phase ;; keeps track of the phase* f# y9 w1 u8 L# y- i/ G
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
; c! Q, U3 D% s: \ current-light ;; the currently selected light- C" l/ N/ p. y' ~
) U- X; Z+ X( {; l1 K; s ;; patch agentsets
5 Z' ?) M, p7 F' b+ z intersections ;; agentset containing the patches that are intersections& i8 ^8 G$ N& s7 j2 N( Z6 R
roads ;; agentset containing the patches that are roads; z* G$ A+ g5 A
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turtles-own
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speed ;; the speed of the turtle
* y6 s( Y2 w- ]+ w; Y up-car? ;; true if the turtle moves downwards and false if it moves to the right6 e+ F, ~" A/ H) |6 c/ m$ y' @
wait-time ;; the amount of time since the last time a turtle has moved) q% C) v D( A" P) G
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" L6 \4 N2 `! s p* k2 }patches-own* x; c* t' Y q- r" ?' G
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( x! [( }5 ~( t% C3 g' l intersection? ;; true if the patch is at the intersection of two roads
: N7 p0 l0 Q" q, Q, k5 ` green-light-up? ;; true if the green light is above the intersection. otherwise, false.: k# n5 i3 z. ]1 w. }0 \
;; false for a non-intersection patches.5 M( d/ g8 g. Q7 `( F. M
my-row ;; the row of the intersection counting from the upper left corner of the0 C9 K$ H7 T+ L4 }" R! r
;; world. -1 for non-intersection patches.4 I2 n8 a7 ?3 ~" P4 `
my-column ;; the column of the intersection counting from the upper left corner of the5 e; k7 j0 ]% K; w
;; world. -1 for non-intersection patches.
! w! a, F M w* n* X% p; [ my-phase ;; the phase for the intersection. -1 for non-intersection patches.* n+ p- u& }3 J* \
auto? ;; whether or not this intersection will switch automatically.
+ T, J8 u# O* _& x; G5 ?8 r ;; false for non-intersection patches.
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D& f0 j/ @8 r- [8 R. V;;;;;;;;;;;;;;;;;;;;;;
" s% F# X7 l. ^( a;; Setup Procedures ;;
: y' t" J! \+ n! \- U;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
' C% I" c$ h5 z3 ^2 O D;; Create num-cars of turtles if there are enough road patches for one turtle to
* {& t$ r8 Y4 p n8 D% a l! E/ T5 t;; be created per road patch. Set up the plots.
$ n" G. S6 k$ O k/ ~8 b ato setup0 y# X, C) C" p; _& k
ca
; v2 g$ D! @ f: O setup-globals
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1 b9 O5 R3 m5 V' _) D3 ` ;; First we ask the patches to draw themselves and set up a few variables' d+ o/ Q0 z- b. q6 w
setup-patches
1 T9 L0 U5 d( W: V% Y- j make-current one-of intersections1 u. o4 p8 P4 c4 ~
label-current& f" L6 `( Y3 D- a
N4 j9 B; o, `/ g" g set-default-shape turtles "car"
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if (num-cars > count roads); t7 ~/ r( i- W) p
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8 `5 a# H6 ~) T- N5 p user-message (word "There are too many cars for the amount of "' l1 [$ O* E! m
"road. Either increase the amount of roads "
! @" t3 o/ t" C3 _9 ^' Z* n- _ "by increasing the GRID-SIZE-X or "
- a9 B9 ?5 e9 U6 W, `# I "GRID-SIZE-Y sliders, or decrease the "
8 [- t& K& N: Y. z "number of cars by lowering the NUMBER slider.\n"
) ]7 {7 \- a+ X- {3 l0 { "The setup has stopped.")" x+ _+ N1 a7 \) g) a
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
% l# A0 Z1 r/ ]" j* G3 w crt num-cars" O$ N" s% y, ?. A* q
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: U/ P" {. o$ W+ y1 d9 p setup-cars+ Y5 y& J1 o/ M% L. b' }% p
set-car-color
/ x- m. q, w/ ^% B0 k9 F( s# F record-data8 Z0 S n4 g$ X8 V4 J
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;; give the turtles an initial speed
# l) p/ Z) ~9 X% g! g ask turtles [ set-car-speed ]
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: F! e' E5 r, c, q/ t) c reset-ticks& N$ n2 y8 E- R6 H
end% b% B: u; o9 t, q2 ?
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;; Initialize the global variables to appropriate values. C' Z( b9 ~& F# V# `( h/ [
to setup-globals4 b9 a0 Z+ y- x, H' C" G7 `4 @
set current-light nobody ;; just for now, since there are no lights yet
2 c! p6 E) F4 y, M set phase 0% Q) T6 E! f5 V
set num-cars-stopped 0
' V7 K; z C3 g3 i! j. P2 Y set grid-x-inc world-width / grid-size-x
; D; q3 C: o0 U3 C" M6 u4 B1 N set grid-y-inc world-height / grid-size-y+ x3 Q( C& ?) T
. d( t! Y. G6 G0 i' Z8 v+ D" x6 v ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary- r4 I6 Z- ]5 h* c
set acceleration 0.099
2 t# o, n, w- m: v5 a7 Jend. B6 V2 Y0 Y7 C8 l: f0 T8 p1 r
1 b. |' b) x% D6 r$ D4 f. n+ @8 ~;; Make the patches have appropriate colors, set up the roads and intersections agentsets,1 f) Q& X1 s* }+ w8 q9 v# A
;; and initialize the traffic lights to one setting2 d! f1 s/ l e! H5 s
to setup-patches
, G) G# p$ ]: Y. ~/ G ;; initialize the patch-owned variables and color the patches to a base-color
# S5 H. Q* e f ask patches# F% s7 b; G, v8 X
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+ v+ A7 v! V( ?. ?! M6 I7 L) S# T set intersection? false# O* ?% ~0 X7 F- z+ m
set auto? false4 B& g7 \$ _8 g: f" M
set green-light-up? true. Z- Q% b# Q3 X6 D
set my-row -1. L+ t. v% P) v8 [
set my-column -1' } k `5 }& {. G
set my-phase -1
+ v" L# \& \0 ` set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
5 k3 q. N* |2 m) c/ k F) S set roads patches with
0 M8 G7 c K& G" |4 ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" n H* c q5 C" ?4 P (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" q+ z- D6 d9 q3 D set intersections roads with
- j9 W& N* d3 T6 O; ~ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and) h" |& ^, L9 A& p4 C' U
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 h! m2 c' a- H7 U1 T- z
" L& Z7 z5 U& t9 Z$ h ask roads [ set pcolor white ]- h4 o' \3 f1 ]) A; a/ }
setup-intersections, {. E1 s- x- Y
end/ v$ O" V2 H1 |5 p" d5 h! |; r
其中定义道路的句子,如下所示,是什么意思啊?
6 r* g# R3 I3 `, f# @6 _ set roads patches with; y, e- U; ]+ y8 D* \' B
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: k" l* i( }. H, y, i, Q* R8 }* p (floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 T/ k) i" y9 _; M: w0 A: | `
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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