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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。
5 O: h4 T7 i) u% _/ v/ B( wnetlogo自带的social science--traffic grid这一例子当中, N& ]; t' }) J8 Y
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction |0 x! X3 u' H) z
grid-y-inc ;; the amount of patches in between two roads in the y direction
' e1 |4 M0 A; R3 }9 I c acceleration ;; the constant that controls how much a car speeds up or slows down by if
( x0 ]* y, u1 \ _8 j! H ;; it is to accelerate or decelerate1 o9 X& O- [& O: O u+ J
phase ;; keeps track of the phase
9 A1 ^0 @/ f# Q. @/ i" m num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
4 }) P7 R& M3 |' }: Q current-light ;; the currently selected light& @) A- n r* }
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;; patch agentsets. D5 E! u# g8 {6 w% N) { T. R
intersections ;; agentset containing the patches that are intersections2 w0 W/ P1 v! q1 [
roads ;; agentset containing the patches that are roads! H1 S6 \9 t2 z7 M; p% L
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, |7 X! v2 H! J" }+ aturtles-own
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F2 [8 n3 B, b" y% Y/ {1 ^ speed ;; the speed of the turtle
8 E- {' w$ r# x0 a6 n$ [! g8 V up-car? ;; true if the turtle moves downwards and false if it moves to the right4 v9 o7 y. m. b; x* Y1 a% H: o' S
wait-time ;; the amount of time since the last time a turtle has moved
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. P0 ?5 v. s. d. L5 bpatches-own6 k+ ~. N7 {4 Q. x* x
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' i2 q8 ]6 R, J) Z intersection? ;; true if the patch is at the intersection of two roads
% R0 C% O V; k0 Y2 i2 o6 w green-light-up? ;; true if the green light is above the intersection. otherwise, false.$ J. j+ N9 H5 m& A0 q: ?8 E
;; false for a non-intersection patches.
$ V5 P6 Q0 P0 r* u my-row ;; the row of the intersection counting from the upper left corner of the
* r3 f: X( ~' B* N+ p ;; world. -1 for non-intersection patches.1 o. T r; _' S6 e* Q& C& f
my-column ;; the column of the intersection counting from the upper left corner of the8 v: b3 U: j4 n4 ~
;; world. -1 for non-intersection patches.
; ?8 G: R1 D l% g" Q+ S" m: b my-phase ;; the phase for the intersection. -1 for non-intersection patches.6 U* `4 t! p$ o2 [9 \3 K
auto? ;; whether or not this intersection will switch automatically.
; z3 f) M& A: s: j/ n' T ;; false for non-intersection patches.9 f1 H/ ?: B/ O+ G! Q- E
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;;;;;;;;;;;;;;;;;;;;;;
; W" C) n" t9 |! w6 q* [ u) Y;; Setup Procedures ;;
- i; ?; [; h, d7 r;;;;;;;;;;;;;;;;;;;;;;
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7 R G9 N1 j& P2 R+ x5 n;; Initialize the display by giving the global and patch variables initial values.
' L& } _+ k: f! W+ q' H, s$ X9 D;; Create num-cars of turtles if there are enough road patches for one turtle to1 v* w N; S. W+ n
;; be created per road patch. Set up the plots.
1 c% v5 ]+ D8 E/ g: `to setup& E& [4 K$ ~ W2 O; |$ Y
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setup-globals
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6 I! o8 ~0 d) Z ;; First we ask the patches to draw themselves and set up a few variables6 w ^% F2 H" \3 m
setup-patches7 S( G2 w8 Y" z' ^6 c1 k
make-current one-of intersections
, ~2 M$ a1 Y6 ~, } label-current
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set-default-shape turtles "car"! y/ u2 }2 r! s+ J% I& t$ d4 Y
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if (num-cars > count roads)) \6 ^; o0 T; m& A+ g
[
; H% y* _1 e/ Z3 n4 Y( ^ user-message (word "There are too many cars for the amount of "' Q6 m- ], X- X, R" g# ~1 v
"road. Either increase the amount of roads "
, j0 {6 d5 o! a# j- W$ n- G" c "by increasing the GRID-SIZE-X or "
3 d* V; }" j) B0 e6 E "GRID-SIZE-Y sliders, or decrease the ". E* h8 U7 G& o) K
"number of cars by lowering the NUMBER slider.\n"/ K# V( z! R7 j( h* `& u
"The setup has stopped.")
6 X- V' \7 _0 u6 _$ P9 s stop: s6 @% {7 L5 S) I
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
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setup-cars
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' v4 E9 ^- [& ^, b$ D$ d. A! S; O record-data+ Y5 Y. x. g2 F" C/ a7 m
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;; give the turtles an initial speed: ?7 b5 k/ ~- M% V2 k# e
ask turtles [ set-car-speed ]. t$ }# ^6 p) q* m
; |3 ]& H+ o- `+ U' v2 U9 \7 f reset-ticks8 V. m" ]# `% J4 d0 A
end+ W- v! q& k$ ? u# M# t, l# X
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet/ V$ a4 g1 G1 w8 P( \
set phase 0
- A9 Z; n! Y4 [# _9 ~ t6 g set num-cars-stopped 0
8 u- S v% m, h. \# N" s$ V7 M set grid-x-inc world-width / grid-size-x
3 F0 @) _# I. P set grid-y-inc world-height / grid-size-y( ^! T4 L# c5 p3 T# p! D. J4 k2 j
" v) D1 @& h& ]2 C ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
+ Z( d) ?+ i) J set acceleration 0.099( k& B, x8 i5 Y, O& {" u
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,: i% X8 N+ V6 i7 u, ^0 I
;; and initialize the traffic lights to one setting
" u3 _. W. [) ?' z4 U9 Sto setup-patches8 {5 I: n8 {) @4 T D5 B
;; initialize the patch-owned variables and color the patches to a base-color. O9 h, S" Y1 }7 t+ z8 |$ z
ask patches
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8 R9 G3 j7 ^* P- w! M# f, ` set intersection? false
; A' }; {6 ~5 Y& P" G L set auto? false
, T6 ^* t Q- V5 c set green-light-up? true
1 n7 Z- l) Q0 P: F set my-row -1
' X2 h0 v; u. m set my-column -1
. ?" c, `( ~' k3 y' k set my-phase -12 B$ V# c5 L9 H% T
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
" r: B. o I2 _7 b/ _/ Q set roads patches with8 i( [- |' k7 ?7 i, T7 h6 X% y& I- P' Y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' I6 V, j+ k9 l* F4 B8 x2 @5 Z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]. M) v5 E2 N) b
set intersections roads with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]. j( ?' j$ R* a9 O* e& m
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ask roads [ set pcolor white ]/ S( _. N# B* a
setup-intersections) |% t; N" A) n9 _7 y% U# a& \
end
9 d% f+ z U) u4 \6 E其中定义道路的句子,如下所示,是什么意思啊?
' R7 U) t* c# m& Q6 G1 H+ X set roads patches with
2 ~8 a! A* @& J% i4 P3 A8 ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' S& _5 v) Z( e2 \0 t9 u' d
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 k3 ^3 |; S) W$ U0 o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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