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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。! _0 [3 v$ V$ h7 n
netlogo自带的social science--traffic grid这一例子当中,
9 |( w; X) @; H- F8 lglobals
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; k- o2 ~5 y+ r7 l3 t" Q+ o1 w/ f grid-x-inc ;; the amount of patches in between two roads in the x direction
4 Y8 M5 d! m7 b* O i grid-y-inc ;; the amount of patches in between two roads in the y direction
$ |1 x' p& l4 N3 n6 Q1 x acceleration ;; the constant that controls how much a car speeds up or slows down by if
( b7 p, K# R; K8 j7 p ;; it is to accelerate or decelerate) X/ B0 s- \( I" y1 d. q
phase ;; keeps track of the phase
9 { g! b. v1 `+ v) w8 ~# ? num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure7 o! r2 I& f7 M' W7 L
current-light ;; the currently selected light, A) i: U# S+ P5 C; W8 T- _
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;; patch agentsets
. L- j$ O# Z" e intersections ;; agentset containing the patches that are intersections4 J+ g2 v5 @* t) O9 D
roads ;; agentset containing the patches that are roads
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* H. Y# ~. n( e! ^0 Kturtles-own
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speed ;; the speed of the turtle
& `+ z( y" p' w. k! M; p. [ up-car? ;; true if the turtle moves downwards and false if it moves to the right
; ~4 I+ A* x; F$ _0 Z# A. y wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads5 s8 x* l7 y" e" ?- u8 {
green-light-up? ;; true if the green light is above the intersection. otherwise, false.+ P6 M$ m' z3 M8 t5 b
;; false for a non-intersection patches.! x$ p8 \+ @# k
my-row ;; the row of the intersection counting from the upper left corner of the
& d0 z$ b u2 j9 C9 r ;; world. -1 for non-intersection patches.
/ _+ n/ R$ y5 z1 T my-column ;; the column of the intersection counting from the upper left corner of the, {; U& j& E+ |8 R! V& M3 g+ L; r
;; world. -1 for non-intersection patches.
) |' D4 M: N3 f5 d) V N my-phase ;; the phase for the intersection. -1 for non-intersection patches.8 B; _/ F$ Y K B, Z7 L% `
auto? ;; whether or not this intersection will switch automatically.; w; L2 A7 m# j5 } B* Y
;; false for non-intersection patches.+ ?. ~; X1 m& Q7 W7 l. L1 l2 |
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;;;;;;;;;;;;;;;;;;;;;;
7 v3 b0 l+ }- Q: n% j, G% |0 L;; Setup Procedures ;;
8 g u) q+ ^; p6 Q& K! S8 x) V;;;;;;;;;;;;;;;;;;;;;;% m; m" y8 e( c6 S; E
( G6 l8 c; ^ p; T$ `6 b;; Initialize the display by giving the global and patch variables initial values.
2 z7 i1 }+ B/ [;; Create num-cars of turtles if there are enough road patches for one turtle to4 x) z, \6 |# Y: O4 _
;; be created per road patch. Set up the plots.! J* M9 ?. o7 b5 S. r" J% @
to setup% J0 x) M4 _- q4 M. k) e
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setup-globals
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! t+ i8 `3 G! ~; ^7 I; K ;; First we ask the patches to draw themselves and set up a few variables
/ B/ Y7 t7 A, g: V setup-patches/ o1 D1 y" }0 k2 U5 M
make-current one-of intersections
6 {, L6 h$ z1 w% Q. R0 Z: E label-current
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5 Z& g* p# F* s8 ^+ `; n set-default-shape turtles "car"
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if (num-cars > count roads)' {* D* p t6 b1 {) J8 ^" g
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user-message (word "There are too many cars for the amount of "
( w, H: p! b6 c# T5 ?+ Z "road. Either increase the amount of roads "
; N/ \% |* `6 f2 q/ [/ J* ? "by increasing the GRID-SIZE-X or ": \7 u: ?) p. c
"GRID-SIZE-Y sliders, or decrease the "
1 k* i) k* ?6 p+ r "number of cars by lowering the NUMBER slider.\n"
. K) ^7 e1 Y+ h- Z& X "The setup has stopped.")
0 h% P1 S7 h$ G/ d/ s stop1 [- C; n6 f& v M3 b: D1 w! D$ y
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$ g+ K; T; |3 ^) ?3 N1 K: y ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color/ A. L n1 N! R. _" D7 a2 ?& A
crt num-cars
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setup-cars% R( H$ W3 w, i; F
set-car-color& _& H0 t# H0 ^& p/ ?9 A# W
record-data
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" q4 s8 t' c# }& k% t" F ;; give the turtles an initial speed& z$ ~% {1 b. n2 N0 o4 j) H/ e
ask turtles [ set-car-speed ] P; i w i" R$ s1 ~
/ k7 u& X; C, W/ U reset-ticks* c. s7 B D2 O8 t8 {
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
/ f: q$ V4 z( d; x& C set phase 0
9 x+ G; x% a% N) b: C set num-cars-stopped 0
5 T/ h4 f- l6 U set grid-x-inc world-width / grid-size-x
/ h/ V2 y* K+ [/ y3 V% w! i. H set grid-y-inc world-height / grid-size-y& ]3 `! _1 S! p: T; v
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary F& E. |" f; V/ k
set acceleration 0.099% }, @& y1 g ~, h5 g1 F
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
( c1 q7 q/ `) A2 W/ q;; and initialize the traffic lights to one setting9 n& X# x9 E$ S. @: `6 Z" v
to setup-patches
7 ]+ F. Y% z5 Q. S- i8 Y2 J% @. D) @ ;; initialize the patch-owned variables and color the patches to a base-color
2 V8 o S; {; W1 i. T& v ask patches
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set intersection? false
e; d) S3 R1 G0 m. c- p set auto? false
( _$ C A% t! n- a set green-light-up? true2 u( d2 y: S* o3 _. {
set my-row -16 O S4 C" P& b- |
set my-column -1% u; U3 \5 a+ Q }) u
set my-phase -1
5 @5 j3 {' S- L, K: `4 s1 o1 Y set pcolor brown + 3! v( i+ `& Q* s+ I
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5 J3 o) w. ?/ ?% q8 ~$ ]# R ;; initialize the global variables that hold patch agentsets! A" f" W3 v9 r! T) H' [6 B
set roads patches with: _, C" k) I# _" v0 @
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 t9 n* R, D8 W# h5 v (floor((pycor + max-pycor) mod grid-y-inc) = 0)]% R' i6 j5 J5 y2 P
set intersections roads with, E0 l& a* q/ P1 N8 W, p, u2 H
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
}6 H5 O* K/ r, B( c# F (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]' s! L, D7 R/ H: a* K9 j
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?# K# U3 H* H$ c
set roads patches with
6 q! H3 ` C' u8 Z1 v [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ _( Y, |* X* q5 @9 y3 x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 B+ k# D. O( ?$ h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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