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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。& c, H5 a0 G% Q
netlogo自带的social science--traffic grid这一例子当中,
4 }: ?" _0 X2 h! X* X. o+ Q w7 N1 Gglobals* |/ Q: o# i, K1 q9 [( `, G
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grid-x-inc ;; the amount of patches in between two roads in the x direction
" L% I+ ~) \' j+ X0 }) C grid-y-inc ;; the amount of patches in between two roads in the y direction$ A* F* @' H; K6 v
acceleration ;; the constant that controls how much a car speeds up or slows down by if
3 \4 i8 o6 @7 i- ] s. {$ t ;; it is to accelerate or decelerate
8 u* Z8 n3 ? b t phase ;; keeps track of the phase. {# n, g8 {9 {$ T
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
% q% d3 I- A/ [; F1 @# D current-light ;; the currently selected light
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;; patch agentsets
8 |7 J$ w; s1 u0 \" ^ intersections ;; agentset containing the patches that are intersections
/ {& y, ~. ^* l0 g+ q roads ;; agentset containing the patches that are roads
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6 F+ D1 R1 ^( s: o* Cturtles-own' h% s( `9 k1 k" r' a% \+ F4 F
[
+ C/ b: V( h) r6 W/ X6 f, Q5 F speed ;; the speed of the turtle
3 P4 j- D3 u! U+ g up-car? ;; true if the turtle moves downwards and false if it moves to the right
( E M, b* m: K6 o1 O wait-time ;; the amount of time since the last time a turtle has moved
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) ]1 K' o' P! h0 b+ \) wpatches-own
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intersection? ;; true if the patch is at the intersection of two roads3 e: i: f. R0 U8 Z2 |
green-light-up? ;; true if the green light is above the intersection. otherwise, false." V/ i( ~8 l0 O8 y) y( T% r1 s
;; false for a non-intersection patches.$ K4 j/ K5 E- }; @6 i2 @( }
my-row ;; the row of the intersection counting from the upper left corner of the- _) y( p0 M" s D
;; world. -1 for non-intersection patches.3 M; \% S7 G" d- j
my-column ;; the column of the intersection counting from the upper left corner of the7 F" @7 x# F6 h/ ]. u/ o. m
;; world. -1 for non-intersection patches.1 }! w5 r9 ?# V" j
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
: t k/ b1 L1 a6 S' K8 x- H5 h3 u auto? ;; whether or not this intersection will switch automatically.. g+ o# h6 i' C& R2 ?9 F& L1 A
;; false for non-intersection patches.
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2 H. y5 M' T" |6 a0 \) u9 l/ D;;;;;;;;;;;;;;;;;;;;;;9 N7 Z$ ?) h0 F( h& K" X' T1 @, ^) S
;; Setup Procedures ;;& x1 V* K: @5 t E* g
;;;;;;;;;;;;;;;;;;;;;;" i( s# }! t! U( G* x, ~$ |! u
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;; Initialize the display by giving the global and patch variables initial values.
9 [# X1 r0 U& [;; Create num-cars of turtles if there are enough road patches for one turtle to4 i+ d: U5 C% F/ s( v
;; be created per road patch. Set up the plots.8 q0 C* x5 x) S% y/ d0 [" K& l$ ]
to setup
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setup-globals
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) B3 [/ }( x4 `! U ;; First we ask the patches to draw themselves and set up a few variables
" L0 @- e, W: K& ?$ a setup-patches$ L6 r0 f% U# }, T, s
make-current one-of intersections8 f4 E: r4 q& z& U, g# V
label-current; A( v5 f% M2 d
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set-default-shape turtles "car"
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5 d3 ~* G( c' U" m, A if (num-cars > count roads)
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1 E! l6 V7 ?; M5 X' E% f user-message (word "There are too many cars for the amount of "
& _! X9 e: W! w0 b "road. Either increase the amount of roads "
$ W" `$ S2 w* ]7 Z+ }# S# F "by increasing the GRID-SIZE-X or ": N, W: P4 b" X2 B# h- b
"GRID-SIZE-Y sliders, or decrease the "
( T+ c; i) h" O/ i- E2 l7 P4 R "number of cars by lowering the NUMBER slider.\n"6 \: i. F0 a1 m+ u `
"The setup has stopped.")$ R ^* ~$ }8 e1 o! ?1 D
stop8 S+ K0 f! ?1 j' \6 t
]
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' [: ]% M8 s2 V2 O4 a6 S# g+ @ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color: }9 f3 ~6 q% k8 }
crt num-cars( ^ E, Z! l) T5 U; ~% S
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setup-cars# K d, p/ m4 I& `, {
set-car-color }3 X6 T2 z) w& R# [* h
record-data8 d# f9 ^1 {0 ?7 }- P
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- n1 ^5 x6 O: a5 j5 F ;; give the turtles an initial speed1 ~5 P. \2 G' F4 k& X+ z; y
ask turtles [ set-car-speed ]
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reset-ticks1 A/ a; q* [0 h3 d* F# n( I
end
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;; Initialize the global variables to appropriate values
8 G Z% I3 O+ \% Q5 Dto setup-globals
& u& X& ~* e, ], {$ }. n set current-light nobody ;; just for now, since there are no lights yet9 u1 A8 ]" g3 @, ]1 J: x
set phase 0
+ a5 }& a! X$ \" _) v; S6 B set num-cars-stopped 0
* V# A; _- t! B& [( K/ l0 C set grid-x-inc world-width / grid-size-x" `+ j \' F, |- W# @/ u
set grid-y-inc world-height / grid-size-y) H; O+ p. ^5 h2 g6 P0 K
( R0 K1 }( r+ Y, n% Z J ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
) F! b7 E! I( Z% Q2 \: X9 D+ R set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
3 N3 j+ [- y" O. |1 F;; and initialize the traffic lights to one setting
5 d, B3 r3 e8 n# F2 e6 vto setup-patches+ W: G5 k9 ]4 M+ M
;; initialize the patch-owned variables and color the patches to a base-color. g9 l4 F) B+ u, W7 H
ask patches" M t& d) C6 [% _6 G+ b* W
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( T5 \% f G4 z7 @) b& a set intersection? false o8 U& t% ~/ d. a
set auto? false
( X" ~4 e2 |/ O o set green-light-up? true
- B" M2 F1 g0 ~ O; B( C7 s set my-row -1
9 U( G }3 [; T set my-column -1' M6 M1 Y, q( S+ x1 S% S! `
set my-phase -1
7 N k' O+ d2 `' C) X set pcolor brown + 3 N1 r7 F2 ~, A& s7 v' P
]
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2 E. I! T+ B- ]& _1 F ;; initialize the global variables that hold patch agentsets
6 |1 j' i- W! f- q* I4 s' j set roads patches with, \! J& ]) x0 }' K
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ V; E4 F \% H/ n; s# z6 p (floor((pycor + max-pycor) mod grid-y-inc) = 0)]* x6 o# w) ~: K0 m s5 r
set intersections roads with. H& T5 B( `0 N) k' g B
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and5 R) ^$ u% C" S
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 U8 i5 k; U( j& Z1 ?: c
# X* t$ g/ J9 |; S ask roads [ set pcolor white ]5 [6 A, f- ~8 f2 @, n0 q5 t, O: Y
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?
4 X& g- n, k$ N. @& F. O set roads patches with8 [# e) i$ O- t7 S, T5 H
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; \" _9 T* k; v! ~3 R+ @, a
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ [& d# M7 o" {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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