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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。' Z( F, ^( v) N; s
netlogo自带的social science--traffic grid这一例子当中,% ` M+ l2 y2 h- a" m( W, i, Q
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction( Y# i2 M: F9 o% y, c, n1 k
grid-y-inc ;; the amount of patches in between two roads in the y direction, A( Z, K# d1 j! `, q& P
acceleration ;; the constant that controls how much a car speeds up or slows down by if
k: ^; _8 X- [0 u% Q4 P) t+ _ ;; it is to accelerate or decelerate
5 o6 L; D3 \/ \* P0 G phase ;; keeps track of the phase2 v3 \" k {# q0 [0 T
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure3 f/ X! z: f. R8 r- i
current-light ;; the currently selected light
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, s, z8 a* t$ q8 |/ ? ;; patch agentsets
- \6 s) D4 @! O) W intersections ;; agentset containing the patches that are intersections
$ g1 X |9 |3 j- y% ~2 I roads ;; agentset containing the patches that are roads' Y$ P) @$ R- M
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- |- ~! N& \ iturtles-own
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speed ;; the speed of the turtle" X4 ^! t2 {0 \( ~
up-car? ;; true if the turtle moves downwards and false if it moves to the right
~/ ]$ o2 K) q# C$ |" h* k& K wait-time ;; the amount of time since the last time a turtle has moved4 I2 ~, T0 ?! f! y4 p# H
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+ \% f8 m4 T$ J r' _, ~patches-own+ H# ]( D6 B7 ^, R
[
; L8 Q6 ~/ Y0 k6 X; N8 p9 r; p, A intersection? ;; true if the patch is at the intersection of two roads# L# l0 |& z6 A
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
; M+ v7 H9 b" D! { ;; false for a non-intersection patches.9 K! e8 }* r5 _2 N F0 b
my-row ;; the row of the intersection counting from the upper left corner of the
4 M$ e: J/ ?1 M y6 w) i3 f ;; world. -1 for non-intersection patches.6 o$ o! I3 ~( X- w) s" x
my-column ;; the column of the intersection counting from the upper left corner of the
+ g9 k2 j& d; l* x9 e ;; world. -1 for non-intersection patches.5 ?) t8 P$ N% t2 @; i
my-phase ;; the phase for the intersection. -1 for non-intersection patches.4 \; q: O6 A5 |9 n4 V* V
auto? ;; whether or not this intersection will switch automatically.
, O( A( G( x$ W. O ;; false for non-intersection patches.1 N6 k3 h+ I3 `2 \
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9 i. B; u: T! p+ g3 K;;;;;;;;;;;;;;;;;;;;;;1 |' V/ c0 `1 T
;; Setup Procedures ;;) u# X2 {, v( K( ?- D* D
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.) G3 S, j" j# s4 \
;; Create num-cars of turtles if there are enough road patches for one turtle to
1 P( f* D" R N;; be created per road patch. Set up the plots.
- S5 l* n6 M7 q' s, y! \/ wto setup
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# _3 o" k8 q8 a% M5 N setup-globals
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4 c: K: E$ ~4 m% P: q m- j ;; First we ask the patches to draw themselves and set up a few variables9 K% x3 N6 l1 a' |% @
setup-patches
0 N7 e: Y- a) a" Q Z make-current one-of intersections0 K+ @, Z% f# `- E, Q3 v' ]
label-current
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set-default-shape turtles "car"! {& r1 k& U2 F( {' p Q& s
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if (num-cars > count roads)/ o6 d! x. R" s0 l g
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user-message (word "There are too many cars for the amount of "' `. e. I8 ?$ X6 w' _
"road. Either increase the amount of roads "& H+ N) i$ X! x* ^- c
"by increasing the GRID-SIZE-X or "1 j5 q! s- o0 b) O) G% q
"GRID-SIZE-Y sliders, or decrease the "
+ ]9 v( g$ y* y+ w4 z7 q "number of cars by lowering the NUMBER slider.\n"
5 t, }) _7 c# Y: |; g5 q$ h d5 K "The setup has stopped.")4 L! O9 g) v" R% k! L- G; l0 ~
stop3 L0 b) w! q/ j- x) E" J
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
+ \! O7 u. }: |; z d- L crt num-cars8 Z2 i0 S6 z: x' s
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5 D0 w, ~) }+ N) y setup-cars
4 e- I# k* Z% h8 e5 d8 N4 w set-car-color
% Y$ X+ O! s8 T$ c. i( u7 \ record-data
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2 E" I2 j& F9 ]% E1 V2 [) v ;; give the turtles an initial speed. M; S r# Q3 D* m8 f" w
ask turtles [ set-car-speed ]
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( [ f6 b) G' W' d; n' _ reset-ticks
3 w2 @: ^9 D) Rend
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;; Initialize the global variables to appropriate values
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$ J0 I* S0 V( e3 E set current-light nobody ;; just for now, since there are no lights yet
4 O! G t/ h& t1 D5 Z& {7 z set phase 0
; \$ U4 U# F6 j$ L. k$ p( Q set num-cars-stopped 0
* f. c& q* x: w2 a: { set grid-x-inc world-width / grid-size-x
! j7 B& @% P4 Z# V" N$ Z7 B set grid-y-inc world-height / grid-size-y' u$ j6 H& e& _5 J. ~
$ |& u. Y" W1 b ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
5 [% q7 {0 R2 m0 I! W9 | set acceleration 0.099
) v; D: E+ L- i, C) l2 ~end
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1 f. N. `' B* Y: O# T;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 S G8 V% T4 K; q9 w7 ^9 Y, Q! F0 _! D1 };; and initialize the traffic lights to one setting- m8 [( @) \4 q" i5 l% G
to setup-patches( c+ j8 s1 V* h5 ^, p
;; initialize the patch-owned variables and color the patches to a base-color
$ |2 R- E5 H: ^* Y+ y5 q8 C ask patches# Y2 t* u8 K/ @# r. K4 ]
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set intersection? false
* D4 v% K5 Y) T' i/ `6 s8 c1 @; | set auto? false
% \ B; `0 \. u* S E set green-light-up? true
& f- X5 u; `. N2 O; k set my-row -1
( i( R: d; A8 J: W$ Z k set my-column -1
0 X* T- G! Z; N6 q4 V+ Q% V set my-phase -1: h2 `- `" r9 s0 J8 U j1 k
set pcolor brown + 3; s$ }( L+ n% H/ P; v, R. v
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;; initialize the global variables that hold patch agentsets i: A: e @& B. d' r' Y
set roads patches with
. U) l# [ O' G1 L7 I [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: B: Y, b% a* Y4 b, ?- H (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) {5 J" n" Q. B, }! l set intersections roads with5 x- R6 u# T) ` P2 v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 T. b/ c$ d! i8 q3 F; l+ b (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?
& P6 ]' s9 x; q# ]( j4 \ set roads patches with) h4 x: s1 E9 q' T6 `4 Q' C- Q _/ Z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 X2 ^( O/ K8 Q2 k+ v# e (floor((pycor + max-pycor) mod grid-y-inc) = 0)], f3 M# g7 I/ B3 c
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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