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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。
( o& m& ^' Q% g: ~8 F' anetlogo自带的social science--traffic grid这一例子当中,- j5 ^7 V ]9 w% R2 e# L1 w2 z* Q
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction; y% T& ~8 E: n3 d8 ~- D
grid-y-inc ;; the amount of patches in between two roads in the y direction
: Z- `* e* a- {+ A- Q' v/ T+ m acceleration ;; the constant that controls how much a car speeds up or slows down by if
0 ]8 r- g8 L( q, A' [7 d/ ] ;; it is to accelerate or decelerate0 N0 I6 L6 W& O* j6 |! E ?, y
phase ;; keeps track of the phase% U. T- @6 @. F. ~/ z6 \
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure: @6 A6 F2 k$ b @! X
current-light ;; the currently selected light( @" b- F0 R. P- C: E8 |
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;; patch agentsets
- K/ ~/ P+ x7 `- _) u6 m intersections ;; agentset containing the patches that are intersections
8 N: {( o% V( Z/ Y3 i# I% U roads ;; agentset containing the patches that are roads0 ^% D* U1 [; I8 g4 R2 Q
]
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+ r- _: z. V' E, oturtles-own
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speed ;; the speed of the turtle% [% O# I E. \8 s& u
up-car? ;; true if the turtle moves downwards and false if it moves to the right
" u$ [" m# g3 n! g9 W' @2 h wait-time ;; the amount of time since the last time a turtle has moved! Q1 ^& A ]6 I
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2 n& b9 D! D @) r' W& q$ a% G+ zpatches-own( z' `( ^2 Q& i% s/ ]& L
[
+ D/ A3 G( @% p intersection? ;; true if the patch is at the intersection of two roads
# M) M% f+ `; }5 W$ J2 O green-light-up? ;; true if the green light is above the intersection. otherwise, false.( z; j6 _3 T4 y, Q0 {
;; false for a non-intersection patches.
5 X& i: h/ z; S5 O; X( V my-row ;; the row of the intersection counting from the upper left corner of the+ X u% q. t* w0 w
;; world. -1 for non-intersection patches.) Y! d+ I: ?* o! G: k6 a; ^
my-column ;; the column of the intersection counting from the upper left corner of the
( C$ U4 P/ n8 e' Z% P* ?$ X ;; world. -1 for non-intersection patches.$ O) M6 p2 ?! Z2 L- L+ i5 _
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
V- ~, q2 s" P- }7 x* M auto? ;; whether or not this intersection will switch automatically.- I, D% }" }, V+ n# X
;; false for non-intersection patches.
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- L# W2 |$ H$ @3 d4 `;;;;;;;;;;;;;;;;;;;;;;$ B! t6 }) ?8 N3 [
;; Setup Procedures ;;2 X0 x4 @3 ]/ u9 i
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values./ o5 ?9 T8 u$ f+ G. @. U: z
;; Create num-cars of turtles if there are enough road patches for one turtle to8 `6 P" e$ [! t/ J
;; be created per road patch. Set up the plots.4 P M& j6 ^! S: z
to setup3 N/ n2 h) v/ t. {1 G' w& P& l
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setup-globals9 ], Y) P' R4 v- B" z
8 w* p6 r+ c/ L* z5 w- r) \5 l ;; First we ask the patches to draw themselves and set up a few variables
+ h. H1 G4 o# ]/ {. ~% q* A setup-patches
/ \3 R) B* ^+ X% A8 ^9 G: r# ~9 d make-current one-of intersections5 p0 h: [2 P L. o
label-current
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set-default-shape turtles "car"
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* B2 j# I* a' A" `+ { if (num-cars > count roads)3 O! d- i' U% i6 V& P4 q
[
7 |: D; c4 `0 h' h$ c9 |4 X user-message (word "There are too many cars for the amount of "
6 `; K4 G# H( b2 x6 c% R G% U "road. Either increase the amount of roads "$ ], h' ~4 `3 `" \- A
"by increasing the GRID-SIZE-X or ": z5 X2 z# h$ G
"GRID-SIZE-Y sliders, or decrease the "
; x7 A' h) p1 Q1 D& W2 \: L "number of cars by lowering the NUMBER slider.\n"
% p! o# [1 b5 S6 H k$ [1 J1 b "The setup has stopped.")
& }2 `0 I5 m; q6 _ stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
* z6 \( v; O" {3 I x" s( e9 m crt num-cars6 l0 t. |. u. o( @9 J5 u# W
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setup-cars
) e f7 C0 T, r e3 Z8 A) g set-car-color% ~& b! e0 D% _- _1 F: X
record-data' c) t1 ?4 n% l- _) h5 ~
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5 t& x+ \) P; B$ _3 f ;; give the turtles an initial speed
7 @$ u, r5 a; F5 K) [ ask turtles [ set-car-speed ]
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reset-ticks9 X H& m( j% E" j- w
end+ Q0 u& R$ m2 w! C, i
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;; Initialize the global variables to appropriate values! C, E' P: ~: g* l
to setup-globals
( q% A5 W; t! t% W2 t: i: A( [ set current-light nobody ;; just for now, since there are no lights yet y7 y" ?9 C J& {/ y
set phase 0
& M: \4 b# {( Y$ H# T( s set num-cars-stopped 0
O5 l: [, \" f, T$ m: J5 X set grid-x-inc world-width / grid-size-x
+ F N" `- V: O& U P+ I set grid-y-inc world-height / grid-size-y
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; N/ l- w# R$ u% A4 P; ~ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
& C# c2 O! m4 V) d; _ set acceleration 0.099
; i. g4 C- R) ]4 Yend" p) y- d& \, U+ p9 x2 \& p& ^6 Y
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,0 T/ o4 Q* y. @# W) |& a# b7 S5 r
;; and initialize the traffic lights to one setting
w. G, w3 X2 u- Ato setup-patches8 U5 R/ p5 m2 V. W
;; initialize the patch-owned variables and color the patches to a base-color
" t3 C$ E2 Q1 }% W! [ ask patches
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set intersection? false
2 y/ g& G- N& i) w1 E set auto? false
3 W1 ~, p7 [) u2 g3 j set green-light-up? true
/ [* g+ @$ G, W) a9 K0 H" k set my-row -1% h8 M8 O* q* A9 ^+ u
set my-column -19 N. Q: D2 ~/ l
set my-phase -14 u2 M& |3 x! \8 o8 p
set pcolor brown + 39 x& K7 j3 u" _( Q% I I* {* ~
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8 D: t8 I" H6 c h) i( H2 G ;; initialize the global variables that hold patch agentsets
( R. k4 l8 X5 J5 G set roads patches with, v8 \% q3 J1 X% ]" D
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; k; P4 h e, Q2 h (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 f4 P+ ?6 I3 O) [$ b% j
set intersections roads with
1 Z+ F% Y8 h) y/ `" j$ q! m1 V [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
" W1 L7 V: A% | (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?
4 v( v H: {# l set roads patches with
" Z2 X+ s- r4 M. W8 p; C7 i7 J [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or/ T9 z! J' t Y. Z+ K1 t
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 ]( T/ k9 t V' x% @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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