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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 b% l# N x. I# Z6 l! Q4 T
netlogo自带的social science--traffic grid这一例子当中,8 u+ h& w, E8 g& i- g5 |4 Y/ G
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction$ L9 [8 y s9 v% U W
grid-y-inc ;; the amount of patches in between two roads in the y direction
1 P/ b6 @4 Y9 B8 z6 w( z. m1 ?/ { acceleration ;; the constant that controls how much a car speeds up or slows down by if. x# j8 d- V: S" O0 ^
;; it is to accelerate or decelerate G& C6 u8 x) @: U/ {+ f
phase ;; keeps track of the phase
6 }! o9 F4 R3 L7 |9 w! H# Z num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure. y, m6 Z' t3 C) b# h1 S# W' D
current-light ;; the currently selected light! n; p& @( Y- E9 S% s" n
0 x" X+ q% v$ Z9 p# ~$ `7 U1 I* e6 L ;; patch agentsets) F! a6 N3 m# G$ C9 g
intersections ;; agentset containing the patches that are intersections
( j. S5 t( R: O* F: x# a roads ;; agentset containing the patches that are roads
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turtles-own
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* ~8 r6 l) i0 U3 Q, j6 r speed ;; the speed of the turtle
; s" @# O; M) p$ C* I up-car? ;; true if the turtle moves downwards and false if it moves to the right
; }3 i5 @, h7 H! |- v! C" j! Z wait-time ;; the amount of time since the last time a turtle has moved* r6 J* k+ a+ D( b5 ^2 j) h
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+ c7 C6 o$ U+ S. Q6 p! hpatches-own/ V3 P7 e* B! P: ^$ t7 N" x
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$ A# V% e- b2 N# M/ q! @ G intersection? ;; true if the patch is at the intersection of two roads
+ ~/ @, z* f1 o& t green-light-up? ;; true if the green light is above the intersection. otherwise, false.1 G8 S2 t, ?$ E6 H1 @3 O
;; false for a non-intersection patches.
# z! J# ~4 ?" G( y: x: v5 y my-row ;; the row of the intersection counting from the upper left corner of the
6 i G. h6 ^( f) F7 d ;; world. -1 for non-intersection patches.
) s- B- u1 j K/ E5 n4 m' m; A my-column ;; the column of the intersection counting from the upper left corner of the1 B0 p9 P7 R! O9 N: b$ @; W G
;; world. -1 for non-intersection patches.) `$ [6 Y' n/ h
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
* o, c6 R5 Z6 m" J auto? ;; whether or not this intersection will switch automatically.- Q/ O5 v! A) i" k/ K; E
;; false for non-intersection patches.7 w! V5 R$ N8 j3 m6 N7 o3 K
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;;;;;;;;;;;;;;;;;;;;;;/ x1 e, r1 J- ^, F9 h) Y
;; Setup Procedures ;;
+ o; a6 S* ?( |) v. `+ |;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.3 J Z: c7 O; w3 }& P T" R
;; Create num-cars of turtles if there are enough road patches for one turtle to$ n0 K9 t, A4 f4 N" s
;; be created per road patch. Set up the plots.* E- H, ]5 N8 {3 Y1 r8 ]' `, J
to setup* Y) g( k A) D9 s* b9 K" k
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setup-globals) l3 y+ w' x+ J( z4 ^. B
# D5 R5 h$ `+ [$ k ;; First we ask the patches to draw themselves and set up a few variables! Z2 W# _9 Q1 ], H1 e
setup-patches
0 ]$ [8 d' b1 z2 C make-current one-of intersections
2 m1 S' M$ A$ L: ^$ n label-current
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set-default-shape turtles "car"% V( v0 y& V2 e5 _) _2 e
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if (num-cars > count roads)" _ w- e- _' w) h' W- f5 n
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user-message (word "There are too many cars for the amount of "' ?" C y( n8 }
"road. Either increase the amount of roads "
! p* p M$ l. \ r8 M "by increasing the GRID-SIZE-X or "5 y4 d7 A6 a; K" ~% G8 z
"GRID-SIZE-Y sliders, or decrease the " { m1 u: k5 F+ p) w( X
"number of cars by lowering the NUMBER slider.\n"9 B4 N- h3 I0 I; g
"The setup has stopped.")
9 i+ ]5 c# p3 S0 k2 ?( m! E stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color7 Q% z/ t( _& U8 ?2 [% b5 h1 ?
crt num-cars1 K! \' c* `+ @
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setup-cars
1 w( g! v- M, m) ^7 _ set-car-color
- n7 X+ U6 t I/ f$ J record-data
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;; give the turtles an initial speed
j& b9 R9 C7 |: u/ w ask turtles [ set-car-speed ]$ T1 p& o, d& Q
% @% l+ @0 t5 | o' ? reset-ticks9 x5 l) |2 O8 {$ S( G- X
end
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;; Initialize the global variables to appropriate values* Z( h3 ^: M- m6 b# I, _3 R( v
to setup-globals
0 F- ?6 J* d' m set current-light nobody ;; just for now, since there are no lights yet: M/ s, S. G5 g9 {% R K
set phase 0
0 G! p: n5 x" a* [. d set num-cars-stopped 06 t& l2 j& z5 S
set grid-x-inc world-width / grid-size-x
+ }! h2 b1 n) @5 v4 U( z set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary8 p" M7 Y+ D8 j8 R$ s2 `5 F4 `. q
set acceleration 0.099
( T( o- }8 k2 t/ Fend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,: Y- z: q9 R! {2 V; Y0 k. h/ ^$ K3 n
;; and initialize the traffic lights to one setting! x/ V7 l" M0 L/ y: _1 V
to setup-patches: {( O8 n9 g! _6 y9 |
;; initialize the patch-owned variables and color the patches to a base-color% `* j, c: O) Z) P% k
ask patches/ N b2 k; c3 t: ~: z, \3 g
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. d3 `3 A+ b6 K! W, L, W, x set intersection? false' Y) r+ o+ D- S" {! w6 ?
set auto? false6 m, R$ e6 E! O1 E8 q
set green-light-up? true
% o! z2 k7 C6 B set my-row -17 L. w; [6 [5 ]; Y: |4 g
set my-column -1
+ c1 W4 r1 w( ~ s1 K6 j set my-phase -1
4 I% C) j' ^( w set pcolor brown + 3
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3 N; w' s- e& n- Z" i$ |4 Y" t7 k ;; initialize the global variables that hold patch agentsets
Q: z# ]' g$ m% ?( _ set roads patches with
D! I7 M( }- f1 O3 W v [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
+ l0 j6 G# D) N+ Y* Y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]" s/ L! z, M E. B
set intersections roads with4 {8 g, ^2 j6 m$ O6 F/ o
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and1 _" _, B @. [" h% ~& e0 ?! M
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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+ K( r% g8 M, Y* [: |6 D1 E ask roads [ set pcolor white ]
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end5 {) S8 n, l& N9 p& c$ S. O, E2 t
其中定义道路的句子,如下所示,是什么意思啊?
# a$ N7 Y( c( k3 }% S6 } set roads patches with
9 S" O# `6 u% ^7 p- L* f [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: r/ N, V7 G8 n# M' p3 @2 o
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ P7 |0 z2 q3 W
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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