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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 W# M! |% i( y
netlogo自带的social science--traffic grid这一例子当中,
8 }9 d* n8 `4 W& kglobals2 A. N1 o, P; h" a7 s: L9 T3 r
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grid-x-inc ;; the amount of patches in between two roads in the x direction0 J& h# m: ]0 i1 P) r
grid-y-inc ;; the amount of patches in between two roads in the y direction8 B; i7 C+ ~4 \' {" B+ V- R/ D
acceleration ;; the constant that controls how much a car speeds up or slows down by if
( R& E/ ~5 v m# y3 s( H# O ;; it is to accelerate or decelerate0 O; K' w" G4 v) y0 s
phase ;; keeps track of the phase) G2 V( D s( {. b6 Z
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure8 Z& _6 [8 ~) G- i
current-light ;; the currently selected light
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;; patch agentsets
1 e2 A" k) ]' ^! L intersections ;; agentset containing the patches that are intersections
9 I! M3 u, t) D( c roads ;; agentset containing the patches that are roads
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* ]) a9 E+ l9 `# \2 H% }turtles-own
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. \7 z& ~% m& h& n! R speed ;; the speed of the turtle
3 q* m* c# K! I7 w0 W$ J# A- _ up-car? ;; true if the turtle moves downwards and false if it moves to the right
' i( Z: J( i: l0 f& E$ ]5 U& E wait-time ;; the amount of time since the last time a turtle has moved1 z, F$ O; K4 {0 e# f; N6 K+ U5 H+ Y
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a% q: U" G, P c) spatches-own
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$ @+ d w' v- V# n: O2 { intersection? ;; true if the patch is at the intersection of two roads
( K* L M: U0 a/ Q( Z# K3 C green-light-up? ;; true if the green light is above the intersection. otherwise, false.8 a, c0 s/ h0 W- U; D; K
;; false for a non-intersection patches.) S2 ^5 K) z* s. j
my-row ;; the row of the intersection counting from the upper left corner of the* r# _$ n- R1 s( V4 y, L: \ c
;; world. -1 for non-intersection patches.
4 S$ ^% R9 P8 ^8 T; E2 r my-column ;; the column of the intersection counting from the upper left corner of the# b0 e' P W6 ^9 _$ k% J' X) c, S) u
;; world. -1 for non-intersection patches.
3 g4 d% j4 r! U. T/ n my-phase ;; the phase for the intersection. -1 for non-intersection patches.6 y4 p5 E. a, r) c3 z$ N
auto? ;; whether or not this intersection will switch automatically.
! d9 M& v7 J" b1 N5 o ;; false for non-intersection patches.2 }1 b- B0 c( l9 i( N1 Y9 B
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;;;;;;;;;;;;;;;;;;;;;;' |( Z$ T( W$ U+ w2 u1 v
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values., v1 X) u, Z; n) N$ P5 E; k
;; Create num-cars of turtles if there are enough road patches for one turtle to9 w" [& V3 m! G% m
;; be created per road patch. Set up the plots.( w; Y7 g5 x6 k& I& o |$ {
to setup, z- k, v! c4 ?" ~' S! t. z/ L
ca
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;; First we ask the patches to draw themselves and set up a few variables
$ @+ b+ j: |8 `) b setup-patches
9 T9 |' G4 } d) T make-current one-of intersections/ Q* Q! ]2 p$ v9 i0 s+ r; H
label-current7 ?2 I" |* Q6 g2 d9 r. `
+ u4 Q! w9 Z* w4 D set-default-shape turtles "car"6 f' H; P6 ~; g7 _. Z) s+ J
" E( @' H5 y# w5 K- l+ f if (num-cars > count roads)
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6 i' C+ e9 r; Q/ K4 U user-message (word "There are too many cars for the amount of "( P0 Z) ]8 Y; Z0 @4 n: x3 G% v1 o
"road. Either increase the amount of roads "
6 C2 N2 u0 p. D& t0 Q, l0 K7 ^ "by increasing the GRID-SIZE-X or ") \0 F1 P3 h0 H0 t' d4 N4 c
"GRID-SIZE-Y sliders, or decrease the "" d r" t1 E7 D, y4 ]
"number of cars by lowering the NUMBER slider.\n") I! s& S. D1 t- a
"The setup has stopped.")
) S& h3 g- m5 E+ f% r stop
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" x& Y$ V3 U# [* L, w ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color5 e/ i/ H' ~/ a; K& ^& V
crt num-cars( V( V" j8 _; T; Q- f, c8 K# F
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setup-cars
7 N9 o7 B- ]$ Y( D( P' N set-car-color4 w [: R# w+ u
record-data
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2 ?: @' X. h7 Y# i0 N& f% E. p* m ;; give the turtles an initial speed
% v. L4 F5 g( T. O* G ask turtles [ set-car-speed ]
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reset-ticks
8 h. I$ L3 n3 Z0 nend
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' i6 ^9 e8 L v8 k;; Initialize the global variables to appropriate values
& H4 D+ V3 r( a1 g9 d. f7 qto setup-globals
4 d& D( m( e! i! ? set current-light nobody ;; just for now, since there are no lights yet# z% G) u p3 `9 ~8 B# s9 R
set phase 0& p( Z# j3 V& {* {
set num-cars-stopped 0
. _' A N5 _" y/ Z3 c& t4 D5 n) @ set grid-x-inc world-width / grid-size-x' W4 u& e2 | }3 ?& T+ z
set grid-y-inc world-height / grid-size-y
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- b$ d% F: l% r ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
! t9 u" ], A' I, S set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
% j; [+ x7 l4 S. ^0 K;; and initialize the traffic lights to one setting
: S; z; p& o/ uto setup-patches0 Y9 y1 ?7 m3 G; [4 l$ w: i
;; initialize the patch-owned variables and color the patches to a base-color
: v' a8 |1 v8 o! g+ z ask patches
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set intersection? false
$ i/ L9 q' h% ~# }/ V9 w set auto? false
! j9 b' Q8 Y6 x; D set green-light-up? true
% i5 W: h; d! L, T set my-row -1
3 j5 s+ z; G* H$ p8 M set my-column -18 [" P+ |* }- l) {4 M: S
set my-phase -1
* G) q9 N7 w7 m2 o set pcolor brown + 3
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. Y+ T" r* g0 I7 y( M! G ;; initialize the global variables that hold patch agentsets
4 P, O: l/ h6 j1 |" D set roads patches with+ U. T! `4 n6 G z4 N: x
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or& q6 ~- t' [5 z3 X1 S+ a
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 o7 |8 s9 o( b3 n) v; P* U8 |
set intersections roads with
2 _5 \: v9 Z2 v5 F( K/ _/ G' k [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
& O+ b. R8 Y7 R2 G! D/ o4 H2 R0 k9 s (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]5 k2 x/ |, D/ U) S0 ]
setup-intersections
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) D8 z8 C* F! N9 F5 |3 n( {7 ~$ t3 Y其中定义道路的句子,如下所示,是什么意思啊?. R0 E0 C* W9 m( D
set roads patches with
- Q: P% k1 a3 h f: O [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 n& w' n3 Q6 Z* Z2 z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 K+ Z& C. C8 k
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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