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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。# _' T% U5 H8 X% g
netlogo自带的social science--traffic grid这一例子当中,
" h4 G2 |& u' X& y. lglobals
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6 F7 u+ o8 p7 \: F grid-x-inc ;; the amount of patches in between two roads in the x direction7 D& X* ^6 \0 P8 K+ \* c) c/ d" I7 N
grid-y-inc ;; the amount of patches in between two roads in the y direction
) X5 R) A4 d3 F) P ?% j' d. s0 z acceleration ;; the constant that controls how much a car speeds up or slows down by if! S( q6 R' {% @2 s( o
;; it is to accelerate or decelerate& u {( a+ X* H; U/ x
phase ;; keeps track of the phase
1 ?+ u4 l; ]- Z2 u, ~0 U num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
. z7 J2 [. N) Y, r) t" u1 D current-light ;; the currently selected light" P+ K8 M% T$ ]
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;; patch agentsets
" y! b2 Q0 g' l/ ^- d intersections ;; agentset containing the patches that are intersections4 { I7 I! \& |+ _% P
roads ;; agentset containing the patches that are roads, W. v7 m; F; U7 s
]
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turtles-own: F: A" j J: K1 ?; h
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speed ;; the speed of the turtle- q. P k6 q0 `4 W' z% B# z! u
up-car? ;; true if the turtle moves downwards and false if it moves to the right A/ p7 a7 V" C9 I4 Y
wait-time ;; the amount of time since the last time a turtle has moved. L/ G3 V4 v8 N5 z
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patches-own" v j% V- s( k5 i3 }9 b
[
% J3 S- G2 K: |. T/ I; h intersection? ;; true if the patch is at the intersection of two roads7 c9 B% v# B/ {6 L0 N, R
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
& n$ ~+ I6 I! } ;; false for a non-intersection patches.
- Y- d0 S% L( p4 S, z" ? my-row ;; the row of the intersection counting from the upper left corner of the
9 S$ E2 N$ i( x; w1 N } ;; world. -1 for non-intersection patches.
" Z5 S. y" `) R4 U my-column ;; the column of the intersection counting from the upper left corner of the
* G$ E2 t0 Z/ F& ?, E2 a* g. }7 Y ;; world. -1 for non-intersection patches.% x5 ^; B/ v! T- D& ]4 u% S
my-phase ;; the phase for the intersection. -1 for non-intersection patches., |, L2 T8 I: d8 t: J
auto? ;; whether or not this intersection will switch automatically.! U! F1 V& H3 |* F4 n$ F
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
( G' s" J9 H; _" Z4 m z4 M;; Setup Procedures ;;
) ^! X; W" v2 J6 r1 e: B;;;;;;;;;;;;;;;;;;;;;;
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. W9 [( Y5 d" I& a; a/ M8 u$ V;; Initialize the display by giving the global and patch variables initial values.
8 @: ]6 s. I, o( x; P# _;; Create num-cars of turtles if there are enough road patches for one turtle to
% Q F7 @* x, t' m; R;; be created per road patch. Set up the plots.& q& X2 i) k# @/ A3 i- G- D
to setup& {5 {9 v9 E/ S
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setup-globals
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6 b" G+ t+ O3 R# W+ O M* D ;; First we ask the patches to draw themselves and set up a few variables4 Q; ~1 |5 M( W* W' L
setup-patches% x E- v X9 N' b
make-current one-of intersections& n6 q& K% E9 v
label-current
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set-default-shape turtles "car"& Q" `5 ~* e% [. i; i e2 M
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if (num-cars > count roads)' e+ u3 k/ P( L% g$ j. K4 u& M
[
; s6 O3 `" c3 h# P user-message (word "There are too many cars for the amount of "
3 V( }9 ~, G: ^9 h, Z "road. Either increase the amount of roads "
& D% h& L" x0 ?: ~5 O "by increasing the GRID-SIZE-X or "
7 I* e; K. C4 C2 o$ v- N t "GRID-SIZE-Y sliders, or decrease the ": o; Q" E; S9 K1 t# ]
"number of cars by lowering the NUMBER slider.\n"6 L1 k% V, T! K) u' b9 t
"The setup has stopped.")! G* R* h0 g: f% y9 @4 L9 D
stop
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2 X8 r5 C# b9 B- b6 ] ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color* N! X- u1 ]! a7 Z) j4 ^
crt num-cars
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_5 e$ S" x" S5 C2 O4 h0 L setup-cars
$ m; f# {1 N/ V( [5 N& S set-car-color8 K6 f: W7 j4 h2 b/ H }; W9 r ^
record-data, ]- B6 X7 q7 u; w7 h7 n" S
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- I, j8 @- n) h/ n) h ;; give the turtles an initial speed
* E4 o- P# p: G2 f) B5 _5 y ask turtles [ set-car-speed ]) d) H6 G \2 `9 @3 q
7 a; b* f2 [1 G& J- o: z reset-ticks _+ t- U6 | S i
end
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b" ?$ I$ F" _* g0 ], H;; Initialize the global variables to appropriate values
5 R% k( B% A5 J' z( q' g$ hto setup-globals8 f+ ~/ h6 e. ]& |
set current-light nobody ;; just for now, since there are no lights yet
) K. M8 U8 A" c set phase 0
4 P: m3 r9 t9 k! S# V: m set num-cars-stopped 02 C: i, Y) N# a1 e
set grid-x-inc world-width / grid-size-x
" a7 Q1 E# g) v2 p6 q. [ set grid-y-inc world-height / grid-size-y4 m6 L E% c; f7 Z% h9 @
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
2 ~( I; n- m9 G0 B( d set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 i; p2 L' `( ~% I;; and initialize the traffic lights to one setting" j; t/ B k6 a$ _" i' ~' _# @
to setup-patches1 U. `* `0 g; ]- K
;; initialize the patch-owned variables and color the patches to a base-color8 V% Q7 \( p( e) u; Z
ask patches
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set intersection? false
, e+ F/ V) |! ^9 Z3 Z set auto? false
- \1 j3 E/ I3 f: f4 ^ set green-light-up? true
0 q* W# I! F2 v# a& C set my-row -15 q' g3 N: W1 E/ m
set my-column -1* y$ |) s- f/ `
set my-phase -1
. T, p& c: X6 ?/ Z4 r set pcolor brown + 3, r; Z3 F3 [( ]. X" O
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, U: {1 P1 [2 j" k4 s ;; initialize the global variables that hold patch agentsets
7 ^1 @2 h; {8 f4 [* ` set roads patches with
P) b, W! O) U- E2 ^# N9 v [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 H' [! S# \! z( e' u: G% ? (floor((pycor + max-pycor) mod grid-y-inc) = 0)]% x3 U+ `7 ]$ {' ]$ d3 O
set intersections roads with5 Y8 W$ ]6 Z6 P, [6 {: s
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
% b! B# j9 W# H: b) i3 g7 z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 Z" C& T: r& e7 t# B4 N6 I
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ask roads [ set pcolor white ]
2 E0 A8 H3 \+ C0 [. Z setup-intersections9 H" O. L0 `' `% [9 G' K& v
end
9 a& G7 _! o5 I其中定义道路的句子,如下所示,是什么意思啊?$ z& S+ c R9 e1 v/ A5 z* O% `$ O
set roads patches with! c1 N6 a! y& @; D( C8 t
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% A2 V& ~9 \" f0 M
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
! R5 e* x- y+ r( i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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