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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。& t6 G1 \ y" D5 f4 N
netlogo自带的social science--traffic grid这一例子当中,! h8 I" @% ?8 w M
globals
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7 [- y& J+ q% j- h grid-x-inc ;; the amount of patches in between two roads in the x direction
' d9 W/ w7 b. U$ D6 T6 j! `6 \3 d grid-y-inc ;; the amount of patches in between two roads in the y direction0 W5 Y4 |! C3 y# N6 c
acceleration ;; the constant that controls how much a car speeds up or slows down by if
F+ ]+ j! {: n4 u- F ;; it is to accelerate or decelerate: i t. N& T% X; V% `$ c/ V; m
phase ;; keeps track of the phase6 t" ~) {, D9 r& e' K$ t+ o( b8 O
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure6 ^" a) r( U0 ?$ N! T" ~5 I7 C: ?
current-light ;; the currently selected light
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;; patch agentsets$ O* ^; u) F0 n; {% c* a
intersections ;; agentset containing the patches that are intersections5 e% P, |: w) ]# o
roads ;; agentset containing the patches that are roads
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turtles-own- T% C' c( y3 ?" z( W2 f" T' {
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speed ;; the speed of the turtle7 y: t' l! z' i! Q! s; z6 Z- }& {9 b
up-car? ;; true if the turtle moves downwards and false if it moves to the right! ?. r: _! v/ l+ v7 s/ l' g
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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( j4 J3 F3 n3 j intersection? ;; true if the patch is at the intersection of two roads8 v( i$ d" L( ^5 Q# X
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
2 v8 X4 c; t: S' h$ W ;; false for a non-intersection patches.
9 _' n2 l+ \ v$ L' \ my-row ;; the row of the intersection counting from the upper left corner of the7 O t- u3 ~+ d8 I
;; world. -1 for non-intersection patches.6 l/ M/ b d# `* F
my-column ;; the column of the intersection counting from the upper left corner of the8 C$ W, w1 p4 _0 \' v# @0 N8 w4 @
;; world. -1 for non-intersection patches.
' f) n o) _# U, B, c$ G! M0 O my-phase ;; the phase for the intersection. -1 for non-intersection patches. [& s8 u6 `2 g( L
auto? ;; whether or not this intersection will switch automatically./ y3 g( p- y8 x' a8 k
;; false for non-intersection patches." {/ ], p9 q' ]" @0 z
]
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3 d, J+ H& |$ [! b# x$ y" x, T" ^- S;;;;;;;;;;;;;;;;;;;;;;
; k: P: K' B* {! P% z) ]" T5 C! D;; Setup Procedures ;;
/ i% M3 }* z5 m& ]% g;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
$ B* D$ [) J* X; H0 }2 O8 C;; Create num-cars of turtles if there are enough road patches for one turtle to
, x# r: ~$ y5 r. E* s;; be created per road patch. Set up the plots.
9 @! p: Q1 D, |; u& X4 ]to setup6 i7 {* H4 O" p W. _" w/ }
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setup-globals
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* c: b& H9 V" L- ?! g ;; First we ask the patches to draw themselves and set up a few variables
8 z# i; @, g4 D setup-patches4 X7 [5 I7 m7 U+ N8 `5 c0 D1 v
make-current one-of intersections
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set-default-shape turtles "car"
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if (num-cars > count roads)
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8 g1 U. g L" H1 S user-message (word "There are too many cars for the amount of "2 d' L1 H# M$ z9 q
"road. Either increase the amount of roads "
' l/ g |& Z/ ], u( \. a "by increasing the GRID-SIZE-X or "
" j7 y `. Y$ z: z& |7 K& [ "GRID-SIZE-Y sliders, or decrease the "2 i+ l- H# b* a: C3 s* ?
"number of cars by lowering the NUMBER slider.\n"& P: x: |& p" N( N; H0 j; q
"The setup has stopped.")) Y3 v* p( z0 `6 E$ n; _/ A
stop5 \2 Q3 k/ c3 n
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
% _0 S4 Q! _ P, o5 E crt num-cars
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; }# T- ^& C6 Z2 k9 ^! b setup-cars
9 ^! z1 W4 r( u' ?8 f& }' n set-car-color
, p& J2 n. L1 B. @+ h/ j I record-data
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. U6 w" j" ^# x& m: V: K ;; give the turtles an initial speed
6 h8 I( L. y( q, q n2 z2 `5 e6 @; t ask turtles [ set-car-speed ]
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reset-ticks
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. A. n# E$ a% `7 _. u5 _;; Initialize the global variables to appropriate values$ [" Q; N/ u$ s0 K4 u% C' l( ]% S
to setup-globals( ~, d' q9 t1 Q( Q% g
set current-light nobody ;; just for now, since there are no lights yet. J) E" c! V' D- ]$ e
set phase 0
' s9 I; y6 u. ~" C) z8 t set num-cars-stopped 0+ x& t4 N |- `1 k1 L% i
set grid-x-inc world-width / grid-size-x7 C3 a# P2 ~4 P6 g% C
set grid-y-inc world-height / grid-size-y5 f0 E! n: p3 P+ y2 V6 Y* k
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
1 L- K2 w0 r& N! d1 W set acceleration 0.099 `) b8 I9 q8 x/ B. N8 I
end
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$ H4 f9 `9 D, q# C;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
) e# `5 V0 F6 W;; and initialize the traffic lights to one setting5 s! E9 b" z7 N
to setup-patches
+ V+ [9 r/ a* l7 D9 A1 ] ;; initialize the patch-owned variables and color the patches to a base-color
( |2 B; @' L% f ask patches
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set intersection? false4 T6 @2 D, n( c6 y" S' N: L( s i
set auto? false
: k$ p8 r+ k/ q0 P# h X set green-light-up? true; _. x; z$ q) n) F% K! P6 H+ P3 b
set my-row -1+ w8 I9 D6 M( D9 B
set my-column -11 J1 ]0 ]' s; x1 C' U# G' Y: d
set my-phase -18 T9 h% R5 w- V
set pcolor brown + 3+ |0 X5 ]9 h/ v, Y0 e d6 o
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; x* W& n# J! l/ m* G ;; initialize the global variables that hold patch agentsets8 [2 E) P9 N; M# d& O8 g. e1 s, [
set roads patches with1 u9 y8 B1 A& o/ U0 B. x
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: S3 K2 Q1 a9 m$ r; u% s. d (floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 L! v8 Y, H7 S5 s+ c/ V Z
set intersections roads with
% ]; |2 U1 k$ Z5 a) Z6 f1 y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and7 T% Q- | S; I$ ?* l9 Q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]' j0 `6 T; r$ D7 e
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ask roads [ set pcolor white ]4 _5 F5 a, M S. N6 W
setup-intersections" A: z4 m' y+ o7 N9 \, W( k
end
1 O$ J2 B) Q/ P其中定义道路的句子,如下所示,是什么意思啊?
, x2 h) m$ ^/ z set roads patches with( e& ]2 }0 [( @1 b) }% h5 N, K* g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or1 x( \5 H( [5 P# S6 w" e
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& L7 Z v2 W/ o: L/ A1 m0 ]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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