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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。
/ h9 [/ i. V- H4 E0 h, e3 M% {netlogo自带的social science--traffic grid这一例子当中,. k. [4 @! k, ]2 r
globals! O) B) J& i1 y+ Y/ O" u. \
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- ?4 z p& e: h' o grid-x-inc ;; the amount of patches in between two roads in the x direction
/ q0 u2 V5 l/ G9 z2 V grid-y-inc ;; the amount of patches in between two roads in the y direction
+ g3 s7 c- N3 c2 h acceleration ;; the constant that controls how much a car speeds up or slows down by if
2 p6 f, t: K8 `8 ~/ j ;; it is to accelerate or decelerate
- g- \4 `6 D& s7 J C phase ;; keeps track of the phase: l" m* l; {( _7 v, c
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure4 ]8 ^# f0 o2 B
current-light ;; the currently selected light
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' z' @8 H, K8 `. q. z ;; patch agentsets% B' }1 A! F7 J% |( z0 a6 @9 [
intersections ;; agentset containing the patches that are intersections7 l! r, ]4 D# X+ s s
roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle
& v u. C% I2 C4 g+ k2 z up-car? ;; true if the turtle moves downwards and false if it moves to the right( K' E9 C u6 l, P! ?9 r
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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3 R8 Q/ J1 s0 X" D intersection? ;; true if the patch is at the intersection of two roads
9 P2 E9 t ]& y' ? green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! r& E! s8 I0 O: x/ @5 U8 K \! I* X$ } ;; false for a non-intersection patches.
8 ?* a+ ?- [) m, ] my-row ;; the row of the intersection counting from the upper left corner of the
6 {8 @1 J, O5 F. H! r3 o- M, r ;; world. -1 for non-intersection patches.
1 S6 h+ y$ Q. i my-column ;; the column of the intersection counting from the upper left corner of the- p( X6 X5 O, v
;; world. -1 for non-intersection patches.
; @! f( I7 @* B5 K, g" ]* h+ k my-phase ;; the phase for the intersection. -1 for non-intersection patches.' N% y1 d+ ]5 f+ s: q7 W- R( r* S6 D7 b
auto? ;; whether or not this intersection will switch automatically.
9 M p F9 `# M, c) W7 H ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;& x9 I2 q% g0 I
;; Setup Procedures ;;
) `9 F$ L# ^7 V" s& R4 K;;;;;;;;;;;;;;;;;;;;;;, s1 q: f1 Y6 l5 S6 U
" ~+ n# G: V: N0 t;; Initialize the display by giving the global and patch variables initial values.
% d: D* u' E! j* `6 x. M% z;; Create num-cars of turtles if there are enough road patches for one turtle to
6 |' q! r1 O$ n0 j;; be created per road patch. Set up the plots.
! Y6 H1 ?+ v# y7 lto setup
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setup-globals
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% b- S+ L: P4 s# Y& |! U ;; First we ask the patches to draw themselves and set up a few variables' w! z% x9 L) S N2 ^
setup-patches& [ L! h2 g& U( D
make-current one-of intersections" c8 w, \ p% \5 W G: {
label-current
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set-default-shape turtles "car"* W+ V8 m% b+ O% g, p/ }$ e- v
2 p' J- Y+ I% z P/ j if (num-cars > count roads)" r: @9 P, T) G: j0 X
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user-message (word "There are too many cars for the amount of "/ C ~+ e: C& w7 C( k6 u3 M$ Q
"road. Either increase the amount of roads "
: g t) s- ]! K; v "by increasing the GRID-SIZE-X or ") Z# Y1 g( R- O
"GRID-SIZE-Y sliders, or decrease the "
# b: G5 c, ?& `; y7 a2 p* c "number of cars by lowering the NUMBER slider.\n"
& Y# ^' ~5 J9 ` "The setup has stopped.")3 @- e3 W h" R; v
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color) g5 Y$ o; [9 A. Y' `+ G8 O4 ^( |
crt num-cars1 ]7 N0 u2 t8 M7 I# y
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setup-cars
& n% }( G2 |6 `1 g% E/ P+ g4 P! P set-car-color
0 a! J- f& t) k: C4 a1 u# U! T record-data( S, z) O5 [+ i
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* a1 z/ \4 ]( v& p4 Q; @ ;; give the turtles an initial speed$ y8 j8 S9 U# l3 l- t2 D& h9 Y
ask turtles [ set-car-speed ]- N% k) t4 g0 K4 r& h& W( g& b
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reset-ticks
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;; Initialize the global variables to appropriate values
& f4 F" j8 ^1 N. kto setup-globals6 n& m- p* j$ i4 S: I
set current-light nobody ;; just for now, since there are no lights yet9 N! V4 D5 u, ~& f4 I
set phase 0
: u R/ K! w' n$ `5 C set num-cars-stopped 0
# d# ? B* y# k set grid-x-inc world-width / grid-size-x* c0 {3 S4 p! i3 T
set grid-y-inc world-height / grid-size-y5 O/ |# N9 Z$ u
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
# o, S* x. A9 }) X3 L: d1 J set acceleration 0.099; }4 H9 l( \7 v' R, S8 l7 g
end2 Z/ W8 E* z4 _! x T2 H
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 e M0 E* m" n' O# N T U3 \& P;; and initialize the traffic lights to one setting8 _% d" {9 T, q/ x1 R$ B" z+ l
to setup-patches) ^/ q0 V7 v3 k3 ~" z4 b. b0 f
;; initialize the patch-owned variables and color the patches to a base-color
6 m! ]' @! L2 }; z/ j0 R: o9 S. p1 z ask patches
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3 Q. r/ a6 ?9 `/ ?: x2 ~ set intersection? false/ E0 Y0 v) |" t4 Z
set auto? false
1 [+ o& E( O. S V4 u! P set green-light-up? true
( M+ Y) G/ F! E0 q m set my-row -19 T2 y: D- f0 F( |
set my-column -19 y: ^ M$ L5 k; F$ g$ Q* U
set my-phase -1+ L" x& ^: h( @2 Q
set pcolor brown + 3& @" C6 U* ?3 L/ y
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;; initialize the global variables that hold patch agentsets% g0 d2 W- H% }. z1 l% y, f
set roads patches with. [; t( _ c5 z9 t4 _3 Y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 D4 d: P$ B$ P8 z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 v" B5 q* L3 C set intersections roads with* W2 ?# R; x( ~. e
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and5 m4 y) G$ y- |% I! X+ s: D4 F
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 z$ R+ c+ p. n8 Y: |
1 ]! R, N$ B7 v, M5 c7 d+ h ask roads [ set pcolor white ]' @- p- G9 }- R) w
setup-intersections
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7 y, ~& U L5 M其中定义道路的句子,如下所示,是什么意思啊?- g0 j* G; l# s0 [6 p4 }
set roads patches with( ?. d" w$ p0 t2 Q4 I( |- [
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 q+ N% ^9 A! W v. m
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 G: P; A$ T- b. b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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