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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。% Q+ s: k% N7 G: R
netlogo自带的social science--traffic grid这一例子当中,
h% u8 l4 p# p* S! }6 Y' pglobals
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5 H M2 L1 m# z6 D D grid-x-inc ;; the amount of patches in between two roads in the x direction
/ U, u/ L: [9 E j) o) Y grid-y-inc ;; the amount of patches in between two roads in the y direction
) J; |* [: h: h, x; v/ Z7 u& J acceleration ;; the constant that controls how much a car speeds up or slows down by if
* _4 I6 q6 A+ R; x ;; it is to accelerate or decelerate1 O. T& y/ G- R2 M% f. A3 {
phase ;; keeps track of the phase
& T1 p" @4 t3 o6 |2 Y' ~; k6 B" B num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure0 Y7 k; u# Z" V# a) b4 ^/ M" t
current-light ;; the currently selected light6 Q/ W& P& {7 L, [5 P( Q! m% }: n
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;; patch agentsets9 P8 S$ n$ m& l
intersections ;; agentset containing the patches that are intersections
4 R/ ^% n( ]* w' S2 w roads ;; agentset containing the patches that are roads$ J/ ]* a$ o8 q( G4 v" @" b$ R$ Y
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$ U! U" N* \1 G& v0 m r" D& eturtles-own
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8 l3 L" x5 x6 L' J: R; }* A1 a speed ;; the speed of the turtle) p4 z v6 R+ }' _0 Z3 ?
up-car? ;; true if the turtle moves downwards and false if it moves to the right
" r) D* A7 h6 w* `- H wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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2 G' U1 q. Q% [3 V% ^- w intersection? ;; true if the patch is at the intersection of two roads
+ T8 b {. D% @6 X H: }/ t green-light-up? ;; true if the green light is above the intersection. otherwise, false.2 P1 ~" O, z7 C! ?+ s# Z6 F) \3 k
;; false for a non-intersection patches.
2 T- a( y; y; E3 r3 A/ }" J8 ^ my-row ;; the row of the intersection counting from the upper left corner of the) x% J4 u, a1 Z% m
;; world. -1 for non-intersection patches.
* C% e1 f: X, I. F* I; E my-column ;; the column of the intersection counting from the upper left corner of the
2 [0 P) A2 O$ R7 h ;; world. -1 for non-intersection patches.9 b7 L+ J3 T* a, u6 o6 I3 R/ r* u
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
% X8 ^7 t& G! X: G$ o$ w5 ^ V0 Z auto? ;; whether or not this intersection will switch automatically.) y- Y6 ~$ f: X# C
;; false for non-intersection patches.1 t2 Y0 `2 T: }5 T- o& T
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* x: Q0 w" c& u J0 u- @;;;;;;;;;;;;;;;;;;;;;;6 X1 j; i# G' _( h+ r
;; Setup Procedures ;;$ U9 V4 `9 R# k
;;;;;;;;;;;;;;;;;;;;;;! V1 b8 E7 N- F# w1 z7 V8 J F) E: ^5 M3 a
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;; Initialize the display by giving the global and patch variables initial values." S0 Q0 [, C8 H d8 e
;; Create num-cars of turtles if there are enough road patches for one turtle to
% @" C$ V% }4 e6 C$ y;; be created per road patch. Set up the plots.
' y2 {6 L% W/ n" h0 w& Rto setup8 `# W% S( [/ u+ g( o3 S
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+ i# {. s) V$ d9 {' j setup-globals
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;; First we ask the patches to draw themselves and set up a few variables7 E) K8 k6 v2 c( u! i3 L
setup-patches: I/ I3 I7 G+ G% ]* H
make-current one-of intersections
0 w! N/ X" r" D; [7 ?& U" t- } label-current
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set-default-shape turtles "car"
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# }. z2 S: F5 ]! f7 V if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of ") v+ r5 X, v. a* t" q
"road. Either increase the amount of roads "5 W' ^" w. c" M7 d/ w4 I
"by increasing the GRID-SIZE-X or "
' r m# g. v! {' ~* R( T. j "GRID-SIZE-Y sliders, or decrease the "
1 N- Z& u/ p8 @/ Q: \ "number of cars by lowering the NUMBER slider.\n"
& Y ^: S6 v3 S1 \2 L/ l+ ^ "The setup has stopped.")6 ~8 I( L3 Y1 g9 M9 z$ P* r1 H
stop7 D) P! E+ ] N# k+ X! `2 `3 E
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color3 E# k- e9 R1 P! ^
crt num-cars
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; H6 S& I. f! n* l/ u- P6 P6 b8 H5 Z0 M setup-cars6 G7 J" f, z! R% C& o0 Q4 n
set-car-color7 L8 j% z9 P4 e1 y6 O) e
record-data
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;; give the turtles an initial speed) X. [" ~* W, x
ask turtles [ set-car-speed ]
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+ `# T$ K% ^+ `. f+ W4 \ reset-ticks
, d7 x: B) E! {3 N3 j' s$ iend
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;; Initialize the global variables to appropriate values* P8 t6 K$ T5 k0 q- \
to setup-globals
) k5 I/ @$ W8 R set current-light nobody ;; just for now, since there are no lights yet
( x1 p$ X I. ]$ w* j$ D5 j set phase 0. U& q, @! Q0 h4 }( K! I, L
set num-cars-stopped 0
& M& m: ^3 I6 j. Z set grid-x-inc world-width / grid-size-x
* [/ N# f# @; k3 t; w$ O3 b* t6 E set grid-y-inc world-height / grid-size-y9 Y8 b H0 d' Z
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary8 ?8 G; L8 a9 z" Y
set acceleration 0.099
% `5 E9 I: x* V9 H* L4 b% qend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
/ e2 y- [8 i) d# Z9 h;; and initialize the traffic lights to one setting
" w6 ?4 b# {2 Ato setup-patches6 o7 r. w! N' y" s$ g' E
;; initialize the patch-owned variables and color the patches to a base-color8 `" B. u1 w* u$ Q3 Z
ask patches
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& J- R& M h+ V3 k8 ?) f set intersection? false7 h% ?& q. p3 G1 b
set auto? false% A5 r; @1 X {# d$ R2 R5 F, Y. f
set green-light-up? true9 ~1 y$ J) r6 a, R/ `8 w
set my-row -1( t5 Y# K P" D: {1 x
set my-column -1
+ d! P: b) c- I set my-phase -1
3 C9 p0 ]6 o9 u9 I; S$ Q! w set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
' s2 [6 A2 H+ @! ^9 \ set roads patches with3 v+ _7 K, f& m0 k) z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 B" L$ h+ _3 P7 e: Y5 w+ y$ L% W
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( N. c: N" ]( A: o$ ] set intersections roads with
' i# w% ^, Z* z" \& ^+ ] [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
9 z7 s6 n; o3 }" H* |5 S. Y& v (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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, g0 ^# t% v# t# I1 _ V ask roads [ set pcolor white ]
) M8 x1 p1 }& O, w" F setup-intersections
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$ b- y8 d1 l: D; T7 e" [4 I其中定义道路的句子,如下所示,是什么意思啊?+ D! k, k/ i+ O& \5 X% s$ P
set roads patches with
5 V( @; @! x) u6 ]% U/ t. l [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 f4 |$ |9 R% X* Z7 ]& `" m' { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]. R0 q+ n; j: e% I! _! X% S9 D; ?
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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