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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。
3 t# ^+ D, ?, m% q8 Anetlogo自带的social science--traffic grid这一例子当中,4 R/ ^, k- V. V# a
globals7 Q# H1 i4 C" x6 l& x& J
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grid-x-inc ;; the amount of patches in between two roads in the x direction
8 F0 ~" t' N6 w3 N1 f grid-y-inc ;; the amount of patches in between two roads in the y direction! m! u* K/ O+ N
acceleration ;; the constant that controls how much a car speeds up or slows down by if
3 B( U4 v: e4 p0 T ;; it is to accelerate or decelerate# t/ a* }$ {3 O
phase ;; keeps track of the phase( `$ g5 b) U$ G1 _
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure- u! \; n1 Z$ O- s/ l- P
current-light ;; the currently selected light. [4 `4 j' u. }' j* p# N, V
5 o! R v3 A' @1 `* p2 `) _: b ;; patch agentsets+ \- W Z: t7 I; \( o
intersections ;; agentset containing the patches that are intersections
' w6 n9 s/ F4 M' N roads ;; agentset containing the patches that are roads
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& q* v) _0 i( M0 v: W5 Z- \7 P- Xturtles-own
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; \9 O- Y# b% p1 `# ] speed ;; the speed of the turtle; ^( {0 A _$ ?: l0 l
up-car? ;; true if the turtle moves downwards and false if it moves to the right/ Y& n9 N- L4 b# e$ `! A+ H! \
wait-time ;; the amount of time since the last time a turtle has moved2 a7 I0 v4 h8 i* X4 v. K
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# d! @2 ^1 o$ Z0 J' B8 _patches-own- U" N" J( t1 z; L" v6 X$ t
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intersection? ;; true if the patch is at the intersection of two roads
) N$ c' ?) o5 A/ s5 r green-light-up? ;; true if the green light is above the intersection. otherwise, false.. G+ f8 R7 O: A1 I" j& F$ |
;; false for a non-intersection patches.5 N# ?8 f! B0 b' J3 A/ l
my-row ;; the row of the intersection counting from the upper left corner of the
, b0 k( s! P% Z ;; world. -1 for non-intersection patches.
( T7 ?/ k" E: K j2 Y4 E1 Q my-column ;; the column of the intersection counting from the upper left corner of the
" C* o }) [; W1 J, D- }7 G+ x: V ;; world. -1 for non-intersection patches.
- x, }* L/ p& g' ?& Z my-phase ;; the phase for the intersection. -1 for non-intersection patches.
% G9 v4 d4 q4 c* p4 o auto? ;; whether or not this intersection will switch automatically.
q6 E6 R) k) p ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;) j9 u* d) o- y2 F
;; Setup Procedures ;;
+ J, z% J+ N7 C. I6 J8 @& E;;;;;;;;;;;;;;;;;;;;;;2 M+ C9 N5 K0 i3 c z
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;; Initialize the display by giving the global and patch variables initial values.' I3 p: i2 r. P5 }
;; Create num-cars of turtles if there are enough road patches for one turtle to
7 D5 p; J- y& S/ F0 H0 ]. n;; be created per road patch. Set up the plots.
' \: F- v$ M; ?4 h5 x8 W* l/ `+ M. Hto setup
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0 T) C: ?6 f0 e5 \ setup-globals
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; `) L/ M5 D) {" v6 w ;; First we ask the patches to draw themselves and set up a few variables% p7 t/ J, Y9 n1 Q
setup-patches
6 g4 m! E' d/ Y make-current one-of intersections
0 r6 y0 c+ _' S: D1 J! r: G; T label-current+ I/ y: G6 V- Y }; j( i5 E1 ~( ^
6 ^3 v4 w3 s T$ M0 K" C set-default-shape turtles "car", v7 _+ T1 \* W/ W9 m0 A' m3 {
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if (num-cars > count roads)$ a; ^! M- [, a" Q6 P
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user-message (word "There are too many cars for the amount of ", F1 J0 b) l& m1 [! U$ H( j2 ~
"road. Either increase the amount of roads ") i) \0 z# V! ^' v K7 a
"by increasing the GRID-SIZE-X or "3 S# A+ [& X9 [9 C7 w; w" R, L* F4 v
"GRID-SIZE-Y sliders, or decrease the "
7 H+ t9 l7 p/ v/ N% ^ "number of cars by lowering the NUMBER slider.\n"
2 Y( A0 \5 {5 S6 Z "The setup has stopped.")5 A6 `1 ^4 k# n* o
stop2 f9 H, P% ^3 Y: z6 C
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
. J. P: L. f6 ^ crt num-cars+ `9 Q x: z; ?% v/ m! e
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$ Y! y. [) ?: K$ U: W+ F setup-cars! U3 U& n; G7 S5 _5 U W: F3 g1 K9 D
set-car-color
" |$ E5 L3 S$ t9 I0 Y2 o5 w2 g+ V& x record-data8 b8 M, b x2 b$ ~$ ^1 T. c2 R. W$ t- m
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;; give the turtles an initial speed
$ X* ]/ ?8 T$ \( z A ask turtles [ set-car-speed ]
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8 p; R% [# |# m3 g reset-ticks
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P$ j) y- S7 z;; Initialize the global variables to appropriate values. O6 X, B3 \0 V1 t5 \
to setup-globals
1 B# q8 R, [8 f" U; u9 R# h, } set current-light nobody ;; just for now, since there are no lights yet0 r) y6 H- B& g
set phase 0- U% Q( d& R9 C, z( t
set num-cars-stopped 07 z! y* Y3 J3 }/ u5 m# E
set grid-x-inc world-width / grid-size-x
8 l) [3 z2 j) x$ o2 b) F set grid-y-inc world-height / grid-size-y" }3 u0 X. }& y+ h3 S l) q( \
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary3 t# E) d& z1 z8 j
set acceleration 0.0999 m& i; a+ Z# l/ A- ~/ M: R" O7 E0 X
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets," \: r. d5 z* |4 f
;; and initialize the traffic lights to one setting4 P# B& `9 G1 \+ u- o0 Q
to setup-patches! D' f9 ^" F( G0 a" j
;; initialize the patch-owned variables and color the patches to a base-color
}" ]1 R" E# G. a% \. e; i4 B ask patches
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set intersection? false
2 G$ x& V* v/ h3 w. l. { set auto? false9 `1 }3 W5 u+ Z, N
set green-light-up? true; v4 a8 }+ X1 g
set my-row -1% i5 f8 v/ v `8 {! r' h# d
set my-column -1, V: v% u# t+ d/ _. S' N
set my-phase -1
6 c/ v; E. i3 [ s7 O set pcolor brown + 3/ t- O. V) I! N% |& J& i5 B
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O4 C4 e- ^+ P, h: \ ;; initialize the global variables that hold patch agentsets0 e" S& u7 }$ R% S; k7 f! x
set roads patches with
8 K2 F8 n- U) z; M& f! W6 G [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or8 z0 d" X4 \- V0 D! d
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]% X/ v4 q$ n- z j, Q
set intersections roads with
) Q& Q5 @" g+ E Y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and* P* [3 ?) \, N/ c; i: i2 D
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ i" s E9 a o8 m
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ask roads [ set pcolor white ]' c& ~: O* }# v+ Q; r& K- \
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?
. v- `# z8 N( f/ P7 e set roads patches with
7 ]' g- z2 Q3 l [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 |$ {+ y0 g; _8 \
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 p S( `" `5 J [ P4 v; 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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