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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 B: _) w) s3 R( k, J! w; {netlogo自带的social science--traffic grid这一例子当中,
5 N' K& Q) F$ @' eglobals! H: A) b( {5 V& v9 U
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grid-x-inc ;; the amount of patches in between two roads in the x direction: g4 P9 }+ V h7 w
grid-y-inc ;; the amount of patches in between two roads in the y direction
% { O0 I6 d: z; F+ C acceleration ;; the constant that controls how much a car speeds up or slows down by if) \4 Q$ ?3 w( |1 g/ I
;; it is to accelerate or decelerate- R2 @9 Y8 c- j. k* G Y
phase ;; keeps track of the phase
3 ^# w7 p1 ~( i. \ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
. ]# w3 d* _, s6 Z3 {# t$ [$ P% [' R current-light ;; the currently selected light. t& D1 Z* A1 m$ A# m% z0 _1 W- T
9 s" T8 a$ i, x" C8 J [; Q- a5 {+ s ;; patch agentsets
+ T x8 G0 O2 @$ X" G" E2 e intersections ;; agentset containing the patches that are intersections1 L: E- S. p6 I! H* k) O
roads ;; agentset containing the patches that are roads
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turtles-own' ~2 U$ ?. i0 j, c+ ~
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speed ;; the speed of the turtle
1 a; S4 R5 Z3 ` up-car? ;; true if the turtle moves downwards and false if it moves to the right
. r+ H, e* ]6 G ~& O7 ] wait-time ;; the amount of time since the last time a turtle has moved. q# S& g! @. k8 `
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$ q2 T- H% `+ I! ?% z/ s3 rpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
) J7 W$ \: u" T) i8 d green-light-up? ;; true if the green light is above the intersection. otherwise, false.8 B, d" V$ k; N3 ?, T
;; false for a non-intersection patches.7 X/ y) ], o$ U0 A; E% p" z
my-row ;; the row of the intersection counting from the upper left corner of the
' Y" {, v1 y0 q" ` ;; world. -1 for non-intersection patches.
" w; m% R4 [& \0 |2 d' ` my-column ;; the column of the intersection counting from the upper left corner of the
1 W! w9 g9 J; Y8 H ;; world. -1 for non-intersection patches. S5 x+ l- _9 K! R& g$ b
my-phase ;; the phase for the intersection. -1 for non-intersection patches., L8 O; f1 V: b
auto? ;; whether or not this intersection will switch automatically.
! C* s! b- E4 p+ h ;; false for non-intersection patches.
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& W+ F$ i" n6 B% i! W;;;;;;;;;;;;;;;;;;;;;;: u2 j e+ I8 P' K3 o/ `# P0 S
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.9 b, y0 B& c3 B+ Y4 c) J
;; Create num-cars of turtles if there are enough road patches for one turtle to
t, G8 d7 L J;; be created per road patch. Set up the plots.
3 j" B& }# U1 E7 Vto setup
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, v' o5 k, A: z/ g setup-globals: ^( h6 U/ ^+ l9 m, _- A
. Y% q6 |. E% d' M ;; First we ask the patches to draw themselves and set up a few variables; W/ ?: a6 m9 x# G3 y7 X
setup-patches* [: O0 E% T! Z2 [ j* Y
make-current one-of intersections
5 O& K0 n- y9 K4 O6 X0 f" I label-current
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set-default-shape turtles "car"# k3 `3 x6 c) t/ h$ o' N# ?
0 T. j( J& X! B* W, a% b8 O if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "( [! l) r7 M1 g5 _, k
"road. Either increase the amount of roads "6 _& a- u" }: j1 A
"by increasing the GRID-SIZE-X or "/ }. Z* D6 B; p2 \2 k6 S5 k
"GRID-SIZE-Y sliders, or decrease the "
1 @. ? V9 E* [% g, ~ "number of cars by lowering the NUMBER slider.\n"
2 \) v' j- ?5 p/ k$ L "The setup has stopped.")9 w# Q) ~! T8 ?
stop% |' U+ `1 K- |3 g' ]$ G
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7 T3 d! k N) F# o; Y+ g ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color6 d5 W( z* P/ [; F0 J
crt num-cars
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setup-cars, \ ~7 A% _! k R# i
set-car-color
5 |2 B! }+ ]) w: C record-data
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;; give the turtles an initial speed7 C7 l; N7 `- B% n; B8 I
ask turtles [ set-car-speed ]
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; P+ B5 J1 E1 k reset-ticks
+ e6 \0 z W6 b( Fend
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;; Initialize the global variables to appropriate values
$ v: L" G3 U" q) [to setup-globals' P% _- u* I5 p0 n8 |
set current-light nobody ;; just for now, since there are no lights yet
9 C |) _+ u q9 x( {8 V set phase 01 ` y+ V! _7 ?/ M* B& J- [3 u
set num-cars-stopped 0, G4 k0 ?9 H1 @ e# K. u
set grid-x-inc world-width / grid-size-x
" P1 m! c# `# { set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
2 I) P. |7 P4 p8 ^ set acceleration 0.099
" \5 | V3 h5 k9 B4 yend8 `( Z0 S. @+ `. q
' [: e3 o+ M9 ^: K6 N( X8 G8 O- K;; Make the patches have appropriate colors, set up the roads and intersections agentsets,/ H& m, n3 L( t
;; and initialize the traffic lights to one setting
% \% J8 d5 _5 h3 m sto setup-patches f$ E) P3 S! S* b4 J6 b: A
;; initialize the patch-owned variables and color the patches to a base-color
- N' H% G" T& C ask patches
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& D b9 V# b8 n; `9 d- U set intersection? false
4 L6 H: i- R, w0 n0 i4 @ set auto? false
. ~2 l, Z2 u1 o set green-light-up? true
( [! i. P. n% g0 O+ [ set my-row -1
$ `) ]' L; b, G! _ set my-column -16 Z) _- j- I: A
set my-phase -1
" n. a( D6 ~+ P0 H set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets, M2 m2 @, P" v! h
set roads patches with9 R% x# \9 x, N# r* d8 ?2 R+ W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or v& m* u4 P/ \: u8 u4 Y3 ~
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 V+ U) D, e- I8 ` j set intersections roads with
5 Z& w4 b3 X) P! [: S [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
3 X% M0 m8 C$ [2 ? (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?
3 T$ ?) P n" l- z3 M set roads patches with F$ C. T3 A y# I* _- I
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or7 S; k2 b3 f6 z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ L% O6 r' z. D0 a9 u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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