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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 G% t9 a1 U- Q: o
netlogo自带的social science--traffic grid这一例子当中,
: o" N! E4 k9 _9 Uglobals5 {8 U g8 ?6 E1 _: X
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grid-x-inc ;; the amount of patches in between two roads in the x direction1 ^+ K8 }7 E* f8 s3 Y" W! l" o
grid-y-inc ;; the amount of patches in between two roads in the y direction
6 S' H* d7 X4 {* S, s acceleration ;; the constant that controls how much a car speeds up or slows down by if- [: M& G2 k; g7 w
;; it is to accelerate or decelerate7 Y9 Y7 m' E! Y. D
phase ;; keeps track of the phase4 _/ v0 X' z( l% ^. l+ r( x
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
+ k- P# p0 F5 G2 Q5 \0 |1 J; m9 `& ]+ T current-light ;; the currently selected light' d. M& y" q7 g! k2 I: }9 H: L
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;; patch agentsets
) \2 r5 K" x' v3 }5 r, w intersections ;; agentset containing the patches that are intersections! g) \; j9 c; ~$ V7 l. A d9 ?
roads ;; agentset containing the patches that are roads3 S }4 C" F' S: G9 G
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2 z7 _: {0 ], ]- x6 Aturtles-own/ l# l7 C# @. {! y/ [: u! p
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speed ;; the speed of the turtle
2 {8 V% E4 U) Y( m9 q up-car? ;; true if the turtle moves downwards and false if it moves to the right# G6 r: t8 l6 h K
wait-time ;; the amount of time since the last time a turtle has moved- }" d9 u/ J/ a: ?6 k
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patches-own- i) t$ B0 h" a5 v/ y/ k
[
" P1 y4 P( ~! O0 m, D8 a intersection? ;; true if the patch is at the intersection of two roads3 w a+ C! B- o
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
, h" L4 K ^ P* G9 @9 L$ h! J. \ ;; false for a non-intersection patches., y3 `2 ~# C0 x4 x5 n
my-row ;; the row of the intersection counting from the upper left corner of the
C2 r5 J7 e! l5 h0 x2 u% T ;; world. -1 for non-intersection patches.+ t2 d& ?: A" _0 \- Z, a
my-column ;; the column of the intersection counting from the upper left corner of the% t: T' i) b0 P0 A' a' x
;; world. -1 for non-intersection patches.% o; \" D4 e+ l9 h- }- J
my-phase ;; the phase for the intersection. -1 for non-intersection patches.4 }/ n1 k# i9 i2 X/ E8 U, O% K& E) I4 A
auto? ;; whether or not this intersection will switch automatically.
8 a# I8 w; C3 ]( t ;; false for non-intersection patches.6 ?/ }3 N# X; `7 M2 y3 E
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;;;;;;;;;;;;;;;;;;;;;;& }. `4 h/ Z: z( n) i: n
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
5 ~! E* H0 ~7 u G;; Create num-cars of turtles if there are enough road patches for one turtle to3 k. R* ?9 N+ a( d1 M; X5 H0 A
;; be created per road patch. Set up the plots.+ g; V! O0 Q( |% N2 I
to setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
- Y# U% H; n$ v' x+ H) e1 v! ? setup-patches& j' ?/ t* ^* f$ D. e, I3 s
make-current one-of intersections
: f/ X" @) r! ~4 Y label-current) F# B) Y1 q, ~, p6 v, X1 i. I" | S
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set-default-shape turtles "car"
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if (num-cars > count roads)0 G0 U3 G, z! g8 B
[
) Z3 |* ^, `9 C( X user-message (word "There are too many cars for the amount of "
# O2 N7 |8 V# T1 r2 V R# U "road. Either increase the amount of roads "
# z9 S% Y, j1 g. }! A0 ?! G "by increasing the GRID-SIZE-X or "
) E' w0 X. E- ?; H. F( y "GRID-SIZE-Y sliders, or decrease the "
* t+ i' s: ^) M; S "number of cars by lowering the NUMBER slider.\n"+ b1 z0 l; \5 g4 a
"The setup has stopped.")7 P# \6 Z6 H) {! |+ S+ A; N9 _
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color7 m6 s A2 K5 R( Q: }
crt num-cars
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setup-cars
; E5 n! j& A9 O) u+ B4 R" n- a set-car-color1 Y. q X0 U! F& t' ~- A
record-data8 B# d! A6 ^2 F5 ?! g! |6 f
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;; give the turtles an initial speed4 X2 S }' k% ^/ {. e) D; L
ask turtles [ set-car-speed ]
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reset-ticks( q' @) p j% F* c; V5 `
end
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|' S. Z) r8 M' b;; Initialize the global variables to appropriate values' A% }# q2 ^6 M: C
to setup-globals( @% w7 e$ y8 G8 N
set current-light nobody ;; just for now, since there are no lights yet! a* h9 g- R" f' A' T, a
set phase 0! V% I3 B- B+ e& w1 ~; N7 p
set num-cars-stopped 0
% p1 O! p1 b9 m! j, O set grid-x-inc world-width / grid-size-x
4 N7 h! f4 |6 u% T( R& s+ U1 @ set grid-y-inc world-height / grid-size-y( b, |6 l; o! q$ t3 x
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
: P# y0 Y4 I4 L7 f! t0 c4 b set acceleration 0.099
7 a% a: j- G( g7 `+ d$ nend
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3 w# z f. q7 `# Z3 T; J% K;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 R4 \$ ?; _5 X" ^0 p; K, H5 N;; and initialize the traffic lights to one setting
4 U; k& w$ M' p: {3 mto setup-patches7 Q6 c0 E0 ?0 R' k* X8 e% x
;; initialize the patch-owned variables and color the patches to a base-color7 @3 x7 @. _ b$ |0 h
ask patches( ?4 ~+ w) m+ O
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set intersection? false
9 q3 ^4 {/ `1 o) A set auto? false
( l0 p2 Q d# i/ }4 l- f$ t set green-light-up? true# R( {8 A$ \% N* {- E
set my-row -10 O; Z) n1 a: J3 j: S& ^
set my-column -1
# {7 A: n# i" u' T set my-phase -18 X( P: f' u3 a% m3 |, A
set pcolor brown + 3
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! T/ m6 A3 Q2 i* e ;; initialize the global variables that hold patch agentsets
0 q" ]9 H' M1 Z* Q set roads patches with
. b2 x6 n% ^0 s$ ~! l& o% u: K! J [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ u6 i r9 v. l7 p/ G. r (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# d' F* F# x# C7 Y8 y9 L: j. W set intersections roads with
5 T' _) z) `/ V [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
( X# q! x) `! Z2 ] (floor((pycor + max-pycor) mod grid-y-inc) = 0)], K( S( U1 C: o) s+ U! ~ i
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ask roads [ set pcolor white ]3 V8 O8 o" `' O- ]/ G# a
setup-intersections0 J, P* c0 |* a& Q% W( j
end
8 T# b: _* P5 Y# Z5 d其中定义道路的句子,如下所示,是什么意思啊?
/ L' n5 q$ {, j7 G set roads patches with# Y9 K9 r( f% Z- s5 d
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
}, I. W( c, _3 |6 l (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 Q( f9 [3 y$ y8 m5 A$ p7 V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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