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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。
( f1 ~" ~2 s L R: L5 Ynetlogo自带的social science--traffic grid这一例子当中,6 c* z9 y2 h# Z3 L* O% q
globals! w, z$ @& e# m) F( l a' R
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grid-x-inc ;; the amount of patches in between two roads in the x direction
% c6 ^6 O; j* P$ |9 }+ [ grid-y-inc ;; the amount of patches in between two roads in the y direction$ A% L; u5 W, a& D# w
acceleration ;; the constant that controls how much a car speeds up or slows down by if
" L0 d; t# _5 A; I! m% O ;; it is to accelerate or decelerate
( z8 h# V# X4 ? phase ;; keeps track of the phase, `& @/ S0 j- n( E9 L3 v4 R) ]
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure' X. O4 ?, [7 j
current-light ;; the currently selected light* o3 N) b; v, S! f( v5 ^# p4 g
9 l- C$ p) ^! Q- H- e; h! e0 Q- p ;; patch agentsets
& r( A+ B$ f' Q5 A# f intersections ;; agentset containing the patches that are intersections
! d7 X+ k2 p: U9 E6 d6 b roads ;; agentset containing the patches that are roads; Q4 Q) i" t9 M! W! M
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turtles-own
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: J: \2 ~/ S1 m5 ?5 d: _6 \ speed ;; the speed of the turtle$ E% X0 T, q9 g
up-car? ;; true if the turtle moves downwards and false if it moves to the right$ i5 L; H* D* d/ F) i
wait-time ;; the amount of time since the last time a turtle has moved( g4 |$ y0 c! t' O/ v' K" m' U
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
4 S, l. d, N5 H" L6 y+ S+ O green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! g+ X8 U) f% w/ E ;; false for a non-intersection patches.! H* x. n3 I- j( ~
my-row ;; the row of the intersection counting from the upper left corner of the) t3 E/ ?! B9 i& L2 I
;; world. -1 for non-intersection patches.
) g& O/ _9 ]/ I0 P my-column ;; the column of the intersection counting from the upper left corner of the2 M/ u0 ]1 y2 g# z. X5 y U
;; world. -1 for non-intersection patches.
% |4 b) J! c7 h' u$ U5 Q+ u my-phase ;; the phase for the intersection. -1 for non-intersection patches.6 R# H; |2 H, ?/ `- N% q
auto? ;; whether or not this intersection will switch automatically.
, w' T1 G( Y% a( |7 c ;; false for non-intersection patches. M4 z; l# }. Y& @3 ~! @7 C7 u
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# j. P1 a8 I& K. `) U;;;;;;;;;;;;;;;;;;;;;;% e( c) ~& Y# \. ^9 C/ G, K
;; Setup Procedures ;;
$ _7 G4 E$ u% E$ D;;;;;;;;;;;;;;;;;;;;;;& z2 v8 y Z/ g" g7 e0 F
: T9 _% J9 z4 h. e. T;; Initialize the display by giving the global and patch variables initial values.' V0 x3 A3 O5 G5 k8 W5 X; i# Q- p
;; Create num-cars of turtles if there are enough road patches for one turtle to
6 B8 v1 V/ ^/ ^9 b;; be created per road patch. Set up the plots.- f7 `( B% e4 Q( ?. N3 D
to setup
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; h. s4 E+ ~$ A8 T! {1 m1 t setup-globals# q$ `% E6 V; ?- m+ w& I6 f# }
8 I- i5 c+ Y+ f ;; First we ask the patches to draw themselves and set up a few variables
0 j% j; ~( ?; |7 Y7 f0 I setup-patches. c B* P* B& Q1 p+ n7 k
make-current one-of intersections7 x- j+ X. ^" k3 a( X. n4 U
label-current
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set-default-shape turtles "car"5 h' j! @$ I) j
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
. b$ G$ f# W" f7 \% Q "road. Either increase the amount of roads "0 n8 v2 x) s$ s7 K" \3 o
"by increasing the GRID-SIZE-X or "
0 W$ @7 l" Z! @& L9 ?. M "GRID-SIZE-Y sliders, or decrease the "
& j( f) g6 S# r& P4 l9 q6 X/ @ "number of cars by lowering the NUMBER slider.\n"+ r* G5 i5 k/ ^3 {. i
"The setup has stopped.")
% ]! P- ~( w: I3 P. n# c* t" M stop- M2 D: P6 A1 F/ w& j
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# \+ L7 l' }. } A* L$ \ crt num-cars
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setup-cars* Q2 U% Z3 `& {4 f
set-car-color
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& j! i7 }% s: o# m* U' B+ K ;; give the turtles an initial speed, j" ]1 |( J# J8 d6 m- z
ask turtles [ set-car-speed ]; Z9 F; i( ^$ e7 J, X
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reset-ticks, H' g6 l& G, F
end
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' b0 M1 v" U7 s$ S7 n;; Initialize the global variables to appropriate values5 H; J0 P; E2 f6 ^( e$ F
to setup-globals
, \+ V' t3 S$ ?9 z, B4 l; y$ v0 g+ A1 L set current-light nobody ;; just for now, since there are no lights yet1 V" h3 h) ?0 d3 j' ?
set phase 0
; \" \9 A( D& x& G. Q0 d' h set num-cars-stopped 00 c8 ?0 U g# R ~
set grid-x-inc world-width / grid-size-x3 d9 L4 Y1 R, P# Z! D, a
set grid-y-inc world-height / grid-size-y
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+ V3 t; e& z- G! Q; ], f/ ` ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary5 K) p0 f% X' h/ X- F: k
set acceleration 0.099
2 H) c0 _4 W, H' \- Uend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
2 W# W6 [8 ] V1 [4 ?, r;; and initialize the traffic lights to one setting; t: E7 D8 J: [6 p1 t0 x
to setup-patches" p: E, J, X+ }- p3 x& l
;; initialize the patch-owned variables and color the patches to a base-color
& ]. y1 K1 ? [* h$ |% C& t ask patches8 c! T9 a* y& `5 ?5 K/ d! S
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# Z* u2 F; k1 x p set intersection? false
% y: U* \5 z0 ~+ R4 V" S; J# { set auto? false$ k; G$ g6 b( g/ {
set green-light-up? true& r$ g! `- f4 @
set my-row -1
1 N; I" x* ~, W$ }1 q# Z1 B* o set my-column -1
" x+ g5 f& r a( r set my-phase -1
* x9 V3 P: y# `# H. ` set pcolor brown + 31 T) c/ C9 s5 t3 u" }) O! E k
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$ F+ g1 Q& L7 M, G9 Z' u: Z) x ;; initialize the global variables that hold patch agentsets
8 ^2 V+ U* ?6 P" H! Y9 y4 J# I$ f) N set roads patches with
( k& s3 G- y" T1 `+ l8 |) w [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
+ f& ]0 J' N5 B; l8 {7 _ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ m8 i4 I8 W k3 D2 u set intersections roads with
( G' J% f! ?/ U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
: o+ j# x3 W/ k (floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 [" _" Q; Z4 C6 T; y% a X* u
2 K3 }/ G6 x$ _ ask roads [ set pcolor white ]
) u2 U8 K% `" I, U& g: n: E. d$ K setup-intersections1 ? P) d" d. t: T' g: F
end4 N$ K9 ~, @! x# D! l1 l* \
其中定义道路的句子,如下所示,是什么意思啊?
5 E7 F" T. o* n" { set roads patches with
! l( ~; y9 i# U) S2 i/ V8 u [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ T& |5 v& d2 z: z0 `+ |! x& [% _# N (floor((pycor + max-pycor) mod grid-y-inc) = 0)]# n6 b/ i% b0 a0 N4 z/ L3 }8 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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