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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。
) l2 v. x% x: ~netlogo自带的social science--traffic grid这一例子当中,8 H# e" i, j- C5 E
globals4 P' t- q' q9 M. E
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' R9 h, Q8 `' ` grid-x-inc ;; the amount of patches in between two roads in the x direction0 o" C2 c( f0 {" x5 ]. E& H
grid-y-inc ;; the amount of patches in between two roads in the y direction
5 U1 N) x* \& e; j; X6 i/ Q6 t+ { acceleration ;; the constant that controls how much a car speeds up or slows down by if; |" ]* h. l" h H
;; it is to accelerate or decelerate
3 G# A$ G9 S9 `! p: u phase ;; keeps track of the phase
' d5 L& o8 L; g) ~! H3 w; L, l3 Y num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure8 R8 z* P6 h$ G4 H- R: V& J) g
current-light ;; the currently selected light) E( t. m& l1 N* p
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;; patch agentsets
) v4 T. t% i4 G' d0 b- k intersections ;; agentset containing the patches that are intersections
/ `+ n; f4 k5 @8 r roads ;; agentset containing the patches that are roads
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turtles-own6 k. A. x9 d- s8 `% O7 f3 ]3 t
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speed ;; the speed of the turtle7 y: Y. t( y: g+ H, f, P6 V% u. A @
up-car? ;; true if the turtle moves downwards and false if it moves to the right' r/ M2 E, F& A% R1 \: |
wait-time ;; the amount of time since the last time a turtle has moved* k% n; O6 `' D) b! m# K( \/ h
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patches-own0 \& T3 X* V* V, l
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2 a5 y. w% u! f! h intersection? ;; true if the patch is at the intersection of two roads
* g# d7 j( c3 f8 g- m. y% C+ l green-light-up? ;; true if the green light is above the intersection. otherwise, false.+ {0 n: }- T& f B3 u/ ]1 v, P3 ?) M
;; false for a non-intersection patches.1 a; _( X6 z( a* p; m) M
my-row ;; the row of the intersection counting from the upper left corner of the
' T( w1 `/ }) g9 A) g ;; world. -1 for non-intersection patches.
$ x. _# {3 {! P5 v4 M- L my-column ;; the column of the intersection counting from the upper left corner of the
5 r4 {3 T1 `+ ~' K: ? ;; world. -1 for non-intersection patches.
g0 ]) h: f: S3 m: k my-phase ;; the phase for the intersection. -1 for non-intersection patches.# m' {' o) O2 _# e p8 Z7 L, {
auto? ;; whether or not this intersection will switch automatically.
/ E, D9 K+ [4 e" y. u: m0 a ;; false for non-intersection patches.+ q- l$ _1 O5 a/ c& Q% I- P
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% ]# Q' _) z+ i o6 u0 c;;;;;;;;;;;;;;;;;;;;;;9 u) P% }' d, P w: Q% J; [% F! E
;; Setup Procedures ;;# T8 s% |$ U! n# q
;;;;;;;;;;;;;;;;;;;;;;
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# ^* E0 B- k" X6 Q6 z;; Initialize the display by giving the global and patch variables initial values.
% _! w% j! k- n' C;; Create num-cars of turtles if there are enough road patches for one turtle to- V2 n3 Y1 H: f6 t" S( H r
;; be created per road patch. Set up the plots.+ s$ R. |. t7 x, b! `- X9 o
to setup
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setup-globals5 _1 e& l9 E9 P8 r7 k' @1 E4 D
/ }; w2 S. o+ p# E! o) S ;; First we ask the patches to draw themselves and set up a few variables; j& @ E$ o4 F( O# k0 T7 [
setup-patches" V! n. ~. x! K5 z8 M0 c' A. p
make-current one-of intersections! S# c5 }3 @# K7 R; N+ C1 f/ d0 g
label-current
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set-default-shape turtles "car"
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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 "; _7 [1 e7 H! P( C. ~; D4 C/ H
"road. Either increase the amount of roads "
$ P1 N+ h4 C' B "by increasing the GRID-SIZE-X or "
1 A# Q( M, L% ^! g" N. k "GRID-SIZE-Y sliders, or decrease the "
7 e0 v& J6 H0 G "number of cars by lowering the NUMBER slider.\n". o/ s) P. }+ Z" F% m4 o
"The setup has stopped.")& A" |, h# R: R# H5 ~* G1 Y
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
" u. q$ t; ~' }( m& q crt num-cars. U$ e Z8 F! [9 R+ K% p
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( ^- p- q% ^+ J$ v% d setup-cars
; k$ S" b; v2 H/ D set-car-color- m: [0 o* i/ Z! b, e
record-data# v7 R7 P5 U) f, m G5 E3 G& p- D
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;; give the turtles an initial speed9 g, D9 F" f* p
ask turtles [ set-car-speed ]( Y9 j" o. ~0 A! ~/ y0 {
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reset-ticks. t& v3 `" w; L6 p% k
end- | F9 W# d9 z- P
Q( m+ O6 l/ |8 u9 U;; Initialize the global variables to appropriate values
# r% F& w: w; q) S! \! nto setup-globals! o) T! V/ n1 p- z4 w9 P
set current-light nobody ;; just for now, since there are no lights yet/ u" L5 \* L5 X9 v6 W+ `9 [
set phase 0& k4 s) a- k/ w
set num-cars-stopped 0
9 t5 D% K" F, @ set grid-x-inc world-width / grid-size-x
0 x+ G! f: u P set grid-y-inc world-height / grid-size-y, D! j$ W( N& T! K) W- y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary9 M, t: c" q, j$ G/ o: u9 ]0 S* Y
set acceleration 0.099( f+ p- t3 o; y7 p h# j
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,7 G/ U' j4 L$ c! H$ I
;; and initialize the traffic lights to one setting
/ N0 _1 Q5 Y) K1 e+ J$ i) M- pto setup-patches& K8 S/ {: d, x5 Y
;; initialize the patch-owned variables and color the patches to a base-color
# w; p9 s9 \/ u( n7 Y ask patches* K! F: l9 j$ \. v+ w
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set intersection? false
# ]1 D' r- j. l. B i& C set auto? false& a( c6 j( q" G
set green-light-up? true
. G/ }( ?, B- ]' ~7 s& i0 f set my-row -1& W$ h' {: {5 ]- A9 W( M
set my-column -1
2 p3 U0 S- l5 W: Z' S set my-phase -1/ `8 m3 | r9 V" N
set pcolor brown + 39 P+ X5 q$ W8 [% W4 C6 l' P
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;; initialize the global variables that hold patch agentsets
4 T* J4 C$ R+ n7 }& M) L set roads patches with6 B5 Z3 }+ U5 S' e1 i
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' s1 C. \2 g" [1 {: ^* W% f (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 _9 Z# W0 A* s/ c5 m5 ^ set intersections roads with& N( b3 K2 A3 H1 W5 O
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and% B2 c: i( |# I3 i& M9 g$ z+ }
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 h5 d, k6 f- s: \" F! w& g
: @0 ]6 a& N9 l- q1 ` ask roads [ set pcolor white ]
& N; a7 j; J: a, t3 i 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?; g8 u" O) e. b0 Q
set roads patches with
. v# ^4 ]# Q" J: Y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 M/ ]7 S$ d E; e4 ] H (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ g/ H( ?0 {6 z }
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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