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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。8 ?6 {4 @1 a! T$ k8 {& N
netlogo自带的social science--traffic grid这一例子当中,
' V) e3 C; C# k1 @globals
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/ p0 ^9 D# G: j, a8 ~/ D- B grid-x-inc ;; the amount of patches in between two roads in the x direction/ O, T7 L5 f; C5 G
grid-y-inc ;; the amount of patches in between two roads in the y direction
0 G8 u6 T. X2 c5 c acceleration ;; the constant that controls how much a car speeds up or slows down by if( a1 [. C5 h9 {1 c- ]( y8 }
;; it is to accelerate or decelerate
! i; q7 }, |1 [3 r/ k phase ;; keeps track of the phase) }8 `- W! q2 P- v3 L
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure, b- `% E+ B; l' {1 z' R
current-light ;; the currently selected light* \5 I1 [# j; K# g* m1 |5 m: K
. \* O+ V L' e- G$ {2 X3 E ;; patch agentsets
; Z2 w( _3 b3 W. H intersections ;; agentset containing the patches that are intersections
& F: d' {& @4 H4 Y# ~ roads ;; agentset containing the patches that are roads2 F- ^( ~' z2 |. T; X/ n7 F
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0 j) ]0 Z% A3 a& lturtles-own
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" R o6 D, C0 H0 h' b+ N, w speed ;; the speed of the turtle
; m& {" G$ t7 H2 z up-car? ;; true if the turtle moves downwards and false if it moves to the right
, W! B1 A8 K! ~$ j- n, a wait-time ;; the amount of time since the last time a turtle has moved$ `6 O6 r( J( a
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( ~# x4 P: _# e. V% X& C: qpatches-own
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6 ~2 Q; @3 r3 u9 m intersection? ;; true if the patch is at the intersection of two roads" Y4 `* n1 w" v* R
green-light-up? ;; true if the green light is above the intersection. otherwise, false.$ ]' q' S1 ^, Z; J+ J
;; false for a non-intersection patches.
. G: m& u( N. o3 {5 p2 h2 D my-row ;; the row of the intersection counting from the upper left corner of the( d9 y3 L% I o" ?& w6 u `: Q
;; world. -1 for non-intersection patches.2 X \1 X/ `: A
my-column ;; the column of the intersection counting from the upper left corner of the
8 P5 ?% J& n; g+ V ;; world. -1 for non-intersection patches.% `+ `: Y* Y- \2 R8 e6 x9 u
my-phase ;; the phase for the intersection. -1 for non-intersection patches.' d! { z' \; b* x6 m% r+ |" F2 a
auto? ;; whether or not this intersection will switch automatically.
- Z% V' ]6 f- R: n: t% x ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;' E2 E$ v+ L/ J0 i
;; Setup Procedures ;;+ c' \, r5 z! [/ v
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
) d8 F; X- a! E# x;; Create num-cars of turtles if there are enough road patches for one turtle to
: L. ~9 I' d5 L/ `& a8 n6 w: b% a;; be created per road patch. Set up the plots.& k% Z3 x% G1 Y6 }. _8 J7 d9 ~
to setup
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setup-globals9 w" W; I' V. {0 ~4 H' M
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;; First we ask the patches to draw themselves and set up a few variables
y; Z$ H- C' f' m9 t setup-patches1 {2 S: ~0 ~% [& d: e7 T
make-current one-of intersections
; y' n0 Y: X. T2 S; A& g- ]0 x label-current
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( z4 e' C: u5 R set-default-shape turtles "car"
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if (num-cars > count roads)! ^" p2 W$ h$ |" [1 o
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user-message (word "There are too many cars for the amount of "
( {( I1 c7 |* F5 f8 y; W$ [; z' [8 U "road. Either increase the amount of roads "! l8 Y* l& C; B6 p
"by increasing the GRID-SIZE-X or "
+ I, G# Q: g! _. H; D1 a "GRID-SIZE-Y sliders, or decrease the "
2 Y" ?9 e5 t8 V8 v/ H0 L5 \ "number of cars by lowering the NUMBER slider.\n"( x. O T$ h+ z+ C$ \7 }# H
"The setup has stopped.")
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]
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" C$ f' E, V P ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color* O0 |& T2 S9 {9 ?1 {9 D9 @. K- _
crt num-cars
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setup-cars$ w% G* A N. ~
set-car-color- ^' D5 Q9 Z& D# a; g: S
record-data
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) T9 t" n) p* L" x ;; give the turtles an initial speed
7 M R, R3 K9 y1 F ask turtles [ set-car-speed ]. z4 |5 e' p* v0 N/ ^
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reset-ticks4 y8 D3 }, g, H
end
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;; Initialize the global variables to appropriate values) G" X. c2 K2 {
to setup-globals4 D$ ?' |4 W0 g9 j
set current-light nobody ;; just for now, since there are no lights yet
$ }* p$ r/ [$ T# k& | set phase 0
$ Z* P/ ?8 E" F5 y set num-cars-stopped 0: i4 ]' h. e; |* i+ P4 k a
set grid-x-inc world-width / grid-size-x
7 z# Q$ y; V) | C. N set grid-y-inc world-height / grid-size-y9 M. @' h0 K7 ~6 p4 D
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
3 l! L* t z+ H4 b3 o8 ~ set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
# t4 P! y1 O* M8 I% v4 i8 J E;; and initialize the traffic lights to one setting8 r8 Z/ E0 F- V# S' F$ B7 D
to setup-patches
7 P& x$ c: h+ u ;; initialize the patch-owned variables and color the patches to a base-color) S. q. j. X6 m" d0 @
ask patches! p" \ Z$ F# j" Y! w
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set intersection? false$ ^$ |4 D3 i' f9 H2 F2 y! @
set auto? false, H# T2 V8 G( E1 V
set green-light-up? true; l) y0 Q, ~! g* o: W
set my-row -1
3 v. ^; i" k: R; r: {: E set my-column -1
7 o, L% v: J+ G" I) q( R$ j set my-phase -1
9 i8 m4 u) g1 h set pcolor brown + 30 x4 S. R4 U& |" n- d1 M
]
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;; initialize the global variables that hold patch agentsets
8 @" G3 L. d. i: z! j+ l0 F' ~ set roads patches with9 F8 s$ O4 A+ d% D, V
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; U9 M# j% j1 A" [
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ W# a7 s0 Q# T8 U/ a9 v; R9 u7 g; \
set intersections roads with
* s" Q2 j* o' x% h. r, S [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
" L% ?0 [ _& K (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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; l8 {) Z6 @2 u ask roads [ set pcolor white ]
5 ]0 A. [4 L) G- {9 Q setup-intersections% b1 d8 [8 U [$ M. m/ f8 B
end
9 @* S" I( S7 M( I9 E) F) `4 g其中定义道路的句子,如下所示,是什么意思啊?3 \' x: w0 [- @) @" J+ X
set roads patches with
" t, L0 d3 W2 T( Z, F. X7 N* P [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 S1 P- c; J4 e* z. z# L
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 A( _" q8 S2 h9 ?3 H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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