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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。( K/ q2 T1 ^4 K7 }7 n5 w7 g
netlogo自带的social science--traffic grid这一例子当中,
' G# ?/ H' L& I$ qglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction7 M, ^6 A( b+ u! @8 H4 r- T4 o
grid-y-inc ;; the amount of patches in between two roads in the y direction
6 L5 R. \4 J3 |+ @ acceleration ;; the constant that controls how much a car speeds up or slows down by if
3 l6 f& K% y6 K$ S1 ?+ i) a ;; it is to accelerate or decelerate3 B7 N5 t/ ]2 K+ p2 E; }
phase ;; keeps track of the phase/ T7 J/ r9 b5 V2 ~: ]5 [
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
" X" l( `! H# K4 } current-light ;; the currently selected light
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;; patch agentsets& i3 W( |" G) A6 Q* f9 [+ n- r
intersections ;; agentset containing the patches that are intersections
; z: N* T7 V) M/ i roads ;; agentset containing the patches that are roads# h0 ?# {, r8 I3 m* N6 f+ K! s
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( Z4 a Z" S6 c6 N' x: G' Kturtles-own: S% B, [! {6 z
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speed ;; the speed of the turtle7 x0 c6 ]1 a7 T/ J7 Z/ p
up-car? ;; true if the turtle moves downwards and false if it moves to the right \3 O8 o6 O9 }0 A8 W1 o
wait-time ;; the amount of time since the last time a turtle has moved' _- R0 D3 d( u/ _: C3 e, c; c
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads) Y( z( `- V* J( H
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
3 ]! O9 R" i, h& \ ;; false for a non-intersection patches.
) q6 P' V2 f+ d/ n8 l- @3 P my-row ;; the row of the intersection counting from the upper left corner of the
" n) ~' j. a+ n& Y; ?2 A y8 y1 p0 i# | ;; world. -1 for non-intersection patches.
8 K+ i) u3 w' f, P0 Y6 c my-column ;; the column of the intersection counting from the upper left corner of the
; x+ w/ q7 L# a; S8 u0 i6 Z8 o ;; world. -1 for non-intersection patches.
4 V/ i* D. Y6 ]! U2 n9 |' D' i8 E my-phase ;; the phase for the intersection. -1 for non-intersection patches.
( |- H1 b- T2 W3 g auto? ;; whether or not this intersection will switch automatically.
) a% {$ X. P) t$ p ;; false for non-intersection patches.
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& P' g8 h$ n3 U: f& h;;;;;;;;;;;;;;;;;;;;;;
j1 J2 P$ I. y, z& @3 o! O;; Setup Procedures ;;+ J' O- O3 T: \% E
;;;;;;;;;;;;;;;;;;;;;;
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& F' T, W8 Q, |1 Q* Y% _% y5 W;; Initialize the display by giving the global and patch variables initial values.
: [9 j1 e: r: P; {8 a;; Create num-cars of turtles if there are enough road patches for one turtle to4 \$ Y0 o: L: w& ~ P
;; be created per road patch. Set up the plots.
% h, S& W7 o$ u4 Cto setup( H8 B3 \0 O& v+ z# P
ca
; ?0 w- f. k+ w. s0 O+ \ setup-globals
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;; First we ask the patches to draw themselves and set up a few variables- W5 l1 |5 P- L) U4 u
setup-patches
+ ?9 M1 L4 L6 k, `* G0 r- S1 m! g make-current one-of intersections6 v z* j2 N" `& t) k9 ?
label-current) T( @$ m5 V' c: T$ h. y
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set-default-shape turtles "car"
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if (num-cars > count roads) \7 ?: |7 P: w8 l# Q6 a
[
; y- V7 R T) e, E" U4 R, @ user-message (word "There are too many cars for the amount of "
* M) a- W% T+ ? v6 t8 B+ t "road. Either increase the amount of roads "
8 m" V) q; j8 @# U7 N "by increasing the GRID-SIZE-X or "
3 E' T1 \& x% @$ i "GRID-SIZE-Y sliders, or decrease the "" U) V! H2 m5 l( {! q+ l/ z. V8 c
"number of cars by lowering the NUMBER slider.\n"
6 s; Z5 f2 e8 d! {! E' E/ B "The setup has stopped.")
, N- l# S+ U0 C# t# \ stop: i" m$ F o$ t* J0 m8 [; J* I
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
8 U! c7 L( A% u2 c8 z8 g crt num-cars7 m/ T: A; y; v: E% B3 E
[
7 I; s2 w2 x I; o$ ? setup-cars
+ ]- ~2 B l! W; J' c set-car-color
, d6 [5 y: h! S, d6 ` record-data
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;; give the turtles an initial speed* F5 o$ ]: i4 z+ y
ask turtles [ set-car-speed ]0 ~" i9 R7 ~+ X' z5 c: D6 \
% X$ C: E5 E5 N' y0 S0 Z* Y% i reset-ticks
& j) ~1 D$ K; ~1 z3 Yend$ \, ]" ^# |, H
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;; Initialize the global variables to appropriate values
+ F+ ?5 o4 p, z( j5 @; wto setup-globals& c4 x0 m/ Q1 C% n
set current-light nobody ;; just for now, since there are no lights yet
# n& j( _9 m3 S$ d) G7 i) s# l0 X set phase 05 D9 o' Y' T7 @9 S* a" P3 _# A
set num-cars-stopped 09 _# R) z6 `% T8 V& j8 T
set grid-x-inc world-width / grid-size-x# D4 {$ z3 i6 j. V; o4 v% Y
set grid-y-inc world-height / grid-size-y2 M; e q0 Y7 c; C+ o" i
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary- p# z C/ }, s3 k
set acceleration 0.0997 t, v: {9 e( h- o# i6 t. G7 s
end: |! m# z9 X9 t3 {
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
' [$ H8 f3 K) q9 h;; and initialize the traffic lights to one setting
W1 O7 X3 |3 i: I5 i" Tto setup-patches
K2 a5 g+ `2 p! r; l ;; initialize the patch-owned variables and color the patches to a base-color
9 s7 ~3 D+ \( p/ t ask patches( k) Z+ y& s A( y' m" W3 @+ Q
[
, k* V0 {- B8 p0 l0 Z- i set intersection? false
8 L+ U6 d& c- M+ U9 ~- b set auto? false! g# l8 F" h* k+ i3 }& }
set green-light-up? true# ^) {+ u! \3 I- K( D* k5 {9 o2 A
set my-row -1
. u3 G2 A* c& i set my-column -1
! T& b0 Z/ K- V5 F! Q0 U" E4 { set my-phase -11 q z* }+ O/ I+ \% Z
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets1 G, V# m7 s3 k4 N
set roads patches with
, C# J; o6 @+ z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 b. Z2 i* s! U8 q4 r1 J+ D3 l (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 e3 q) c- X8 Z, N" A# K' C# ^5 Q set intersections roads with
' o6 K* @5 D$ Q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and2 T/ W: @0 M/ Q5 v1 N
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
) ~( ?8 U0 G+ f Q4 T4 R- l3 F setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?
( {7 [9 C8 t9 p. I4 U set roads patches with
# F8 K" Y x/ _5 n3 w1 C9 H+ P [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or Y! h1 ]3 n# {6 Y# I
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 X) ?, ^- ~9 r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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