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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。3 N) ^' S. g- i1 O% j, s% s
netlogo自带的social science--traffic grid这一例子当中,
7 ^" U6 U/ C" Y) O5 Gglobals u |) m4 T8 {+ P9 c2 a' B2 W
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5 ?6 @% y/ e% z3 _% G8 A( v grid-x-inc ;; the amount of patches in between two roads in the x direction" H5 q* q# Y- j; E o `( n2 I' _
grid-y-inc ;; the amount of patches in between two roads in the y direction
$ K+ f( i0 i, a' K8 J" n! Z+ b acceleration ;; the constant that controls how much a car speeds up or slows down by if4 c n, D- ~8 h" Z: p/ d
;; it is to accelerate or decelerate
9 B& W) W b8 Q& r( ? phase ;; keeps track of the phase
1 q7 U9 H5 l% h! X num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure" F5 v: i2 q2 D) U6 X+ D4 g, [$ A
current-light ;; the currently selected light
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% j3 M b2 |, ^) d8 ?: T5 v( @ ;; patch agentsets, c$ [4 I* C( r, J9 s
intersections ;; agentset containing the patches that are intersections- i; B. u" D9 h1 Z- t3 h6 T. \
roads ;; agentset containing the patches that are roads @0 h; t+ |) Q! V+ J
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8 y9 _ @" D/ v5 J' Eturtles-own0 t: G; T: I) c& S7 y0 a
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) M: D& ~& u6 r& m! Q6 w5 O7 l speed ;; the speed of the turtle
3 a7 X7 e# A6 Y. k8 N, z up-car? ;; true if the turtle moves downwards and false if it moves to the right
5 x7 R j& f+ N \4 p wait-time ;; the amount of time since the last time a turtle has moved; H! O/ P! J( k" ?: \3 x8 x' P
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
2 x& W6 g! a/ `. D green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! l' Q' E* E# D) D ;; false for a non-intersection patches.
8 Q e1 x7 {; _ my-row ;; the row of the intersection counting from the upper left corner of the# F; s7 ?/ b1 \$ u8 c8 h
;; world. -1 for non-intersection patches.
& U5 k9 t3 M4 B6 a( R my-column ;; the column of the intersection counting from the upper left corner of the5 }5 P! r; M" Z+ b& Z1 c: l. ?
;; world. -1 for non-intersection patches.
; f6 l! |9 X, k. H my-phase ;; the phase for the intersection. -1 for non-intersection patches.5 Y4 l% w' k$ b" e$ @
auto? ;; whether or not this intersection will switch automatically.! v/ |/ a4 z3 ]0 N$ P
;; false for non-intersection patches.. b$ d/ e8 u+ a# Y# h0 k' l! g
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;;;;;;;;;;;;;;;;;;;;;;0 E) l1 B. d9 I# l
;; Setup Procedures ;;
- W! |6 T; Z4 f( g; a1 F0 Q! h;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.+ O! |& P, m% N& _2 o
;; Create num-cars of turtles if there are enough road patches for one turtle to( v z: l' @, L, J4 }5 ]% s: Y' I
;; be created per road patch. Set up the plots.3 r7 h/ V. {) f! m% [2 Q; ~6 t: G
to setup
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4 l7 b- U9 _0 t5 u2 c0 e/ Y; d setup-globals6 X& _, t1 l- A0 P/ a
5 B2 p0 d; g+ I0 V/ } ;; First we ask the patches to draw themselves and set up a few variables5 ?" v4 Y3 i, I. t* t% o. h$ r+ Q
setup-patches8 D& F7 H! c! f9 V/ H
make-current one-of intersections& q+ p7 S1 |3 r9 X
label-current
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# A9 \# q3 K o B e2 `! G set-default-shape turtles "car"+ }' E. V' U! R, l g8 z& J% q
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if (num-cars > count roads)
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. b; ?; ?/ z9 {! D3 | user-message (word "There are too many cars for the amount of "
7 D* I3 f7 ^+ n3 z: v "road. Either increase the amount of roads "
" T" |' s: G1 h) m( z0 v7 d "by increasing the GRID-SIZE-X or "' C0 y% a# f2 Z9 k. L
"GRID-SIZE-Y sliders, or decrease the "# M- H. A0 d7 ?$ f r
"number of cars by lowering the NUMBER slider.\n"0 o* L l4 z3 f+ j6 {7 y8 M3 \
"The setup has stopped.")' u1 p I# h1 D
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
]* D3 k& ]/ G$ \: c- i3 ] crt num-cars x% D2 S, {$ h# |2 L) t) F' D
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setup-cars
0 u. a8 d8 k# ?$ ?1 K set-car-color
- T1 q- Z l% _1 u8 ~! } record-data4 c) b- Q6 B7 R
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& B8 [7 h& e) ~ ;; give the turtles an initial speed
1 N7 ^* J/ v) c. [- s7 F# n) \ ask turtles [ set-car-speed ]
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+ B! V) `6 F; [0 R reset-ticks
( J; Q+ ]% R2 f: w+ W8 L. ^. q$ {end
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) E* g+ i2 w2 I1 k9 K5 q, o;; Initialize the global variables to appropriate values" W1 [; `) ]) Z" P/ R% l
to setup-globals
: V4 _3 ?* G, w/ i8 v5 I: I set current-light nobody ;; just for now, since there are no lights yet
! m8 N' o2 U( G- S8 t* P set phase 0- M) v1 H# ]8 P9 M
set num-cars-stopped 0
5 \/ P- ?+ O0 m3 X* K3 y! i% R; x set grid-x-inc world-width / grid-size-x- ~: f& B/ m* V* s! q& {" b
set grid-y-inc world-height / grid-size-y3 N% E6 E' y* p3 y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
1 I0 d: | C+ Y+ b9 x: a set acceleration 0.0996 T+ H. O! b$ P$ W1 ~# L
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ v a: Y* V& U6 g2 q* ~2 z
;; and initialize the traffic lights to one setting
- i% M2 o; l/ o# _5 e# ~to setup-patches0 f# Q7 f# G$ C' Q5 o2 ?# Z
;; initialize the patch-owned variables and color the patches to a base-color$ n# }6 [3 t/ M" z
ask patches8 U5 x7 s8 E! q/ G, O9 d
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set intersection? false: E+ x, {2 z+ c) R3 u% q/ x
set auto? false
, h4 N9 ]" ^' n7 @4 A4 ~ set green-light-up? true
- ~! |2 J: l R2 [+ z5 z set my-row -16 j$ J0 j9 a* n+ [) F
set my-column -1% Y- w. o9 q1 Q1 D" A
set my-phase -1
% k( u4 y% }- u; m) s/ H i) x set pcolor brown + 3" {5 b" I! ?; D7 V" K+ u* D! a
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;; initialize the global variables that hold patch agentsets
, ?6 U" R9 {( Y1 {/ S2 F set roads patches with0 P W- [, V, ^! p$ _& t$ n4 L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: L1 [8 c4 [! @
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 O2 W2 j1 U( l& U$ z0 k5 R set intersections roads with
8 m& Y5 E1 g% h3 p [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and/ K8 D E# M/ p6 A) c' Z; M
(floor((pycor + max-pycor) mod grid-y-inc) = 0)] E& F' i# \* v/ C! O9 d! w5 y' W: `
y" Q( A3 f+ p/ c ask roads [ set pcolor white ]
: p- G* U2 R3 ~ 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?
X& H* o4 ^) C3 Y set roads patches with
0 Y; b$ p& C* P$ p! ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) N) O: A$ K6 P5 e- M
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ I- m% _% h2 r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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