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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。
6 e+ g* V' @; B* Qnetlogo自带的social science--traffic grid这一例子当中,4 G( l& C( o, v
globals
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5 y2 P7 ?4 w E! Z; [ grid-x-inc ;; the amount of patches in between two roads in the x direction
$ B4 w; x; y# R) `9 p& i/ W grid-y-inc ;; the amount of patches in between two roads in the y direction7 X6 r/ k5 i! d
acceleration ;; the constant that controls how much a car speeds up or slows down by if e2 B2 L) F* t! K* Y; }
;; it is to accelerate or decelerate
9 I+ E" r z. u! R phase ;; keeps track of the phase7 q8 p) v; O2 h8 c6 _" k
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
* M% J! y# G$ s0 Q8 E2 u$ N current-light ;; the currently selected light
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;; patch agentsets6 Y% M ]( r0 o- j, e3 S
intersections ;; agentset containing the patches that are intersections
) f% v: A; l! v7 W* k roads ;; agentset containing the patches that are roads
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0 g1 E5 G* d5 G, }3 Dturtles-own; g% Y7 J U# F% i( n
[
a U# N F& F, j! ? speed ;; the speed of the turtle$ x9 B0 g; f+ n6 y5 y+ u1 _
up-car? ;; true if the turtle moves downwards and false if it moves to the right
N/ k' Z- q9 f5 Q* @- F wait-time ;; the amount of time since the last time a turtle has moved8 n S, B5 x- L
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
7 y/ M. ]% ]( t' `. s green-light-up? ;; true if the green light is above the intersection. otherwise, false.
2 a8 B' p( @1 `' s# k ;; false for a non-intersection patches.
}: `! Q! z; s6 ? f7 w my-row ;; the row of the intersection counting from the upper left corner of the
# V6 [7 e; Q+ ]( I ;; world. -1 for non-intersection patches.$ ^1 D% M, q0 s0 ~2 ^; z
my-column ;; the column of the intersection counting from the upper left corner of the `1 H6 K2 p6 O' e6 i9 _/ Z1 L
;; world. -1 for non-intersection patches.% w, I1 D. C9 N" l
my-phase ;; the phase for the intersection. -1 for non-intersection patches.+ b3 P' d* h' `; C9 A4 A6 E: G
auto? ;; whether or not this intersection will switch automatically.5 o% |( t+ W. r( C- a# m
;; false for non-intersection patches.
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3 I5 q; G, p* S: a4 S;;;;;;;;;;;;;;;;;;;;;;: @) D# W% s) r8 b' C% K
;; Setup Procedures ;;4 ?' Z$ t' @4 w8 z- k
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.2 e7 s; E. ?1 J4 J* x" d) x
;; Create num-cars of turtles if there are enough road patches for one turtle to6 k: \* x* ?, }
;; be created per road patch. Set up the plots.
: Z. z: A2 F6 z5 R5 ]: @to setup
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setup-globals
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. D( c' G1 E2 J( F) S0 J: T ;; First we ask the patches to draw themselves and set up a few variables
! d P1 a6 ~ z! h0 V0 ?" ?& w3 G setup-patches. D ^' d7 k) ?
make-current one-of intersections
. _# {' b3 w8 x$ S2 w- [+ s9 e label-current
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set-default-shape turtles "car"+ W8 h& `7 ~- Q3 @3 A# M$ v9 S/ r
& M% U5 s, k9 N6 r' U9 | if (num-cars > count roads)
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. F' ? [5 B: [$ L; \ user-message (word "There are too many cars for the amount of "2 [& l0 X( k, e' l" o5 w. H
"road. Either increase the amount of roads "2 W$ ~( M( l8 f3 b( \: }, i
"by increasing the GRID-SIZE-X or "
4 Y+ e4 \$ @: T J "GRID-SIZE-Y sliders, or decrease the "1 G4 o& L3 T c- I' F! y j
"number of cars by lowering the NUMBER slider.\n"' j# P2 W- f) I1 g2 @
"The setup has stopped.")! Q9 s6 C( w. ?4 f/ I
stop6 W+ a5 ]! Y7 Y c+ Y4 |+ j
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' ? s# k4 T+ z/ N# e ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
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setup-cars
+ m) r1 z+ D/ {8 Z( e set-car-color# {% c9 i; P* ?4 s2 h/ I# h
record-data
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5 e$ v9 u/ N b# t' _* E ;; give the turtles an initial speed
# a$ X" G/ T, v { ask turtles [ set-car-speed ]) k2 T: O" w8 ]% z- G7 F
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reset-ticks: N( ?' A G% _: K% h! q
end
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2 |+ S6 Q/ h2 l0 B1 y' n;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
' r; F( K a& G2 K2 u% h7 ~) ] set phase 0
! p% A, Z2 d3 d. s) t* @ I" X9 G set num-cars-stopped 0( y6 t6 u4 H6 \9 P9 h" v
set grid-x-inc world-width / grid-size-x m% v- V+ H& D
set grid-y-inc world-height / grid-size-y, K" d* i i5 R8 N6 L- s
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary7 u& ^4 Q3 ~1 _: b7 q+ ]
set acceleration 0.099% H' O7 C# W! D" i% l
end
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% z/ p/ S$ f! S" T$ z;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
- V$ r5 e' R O. Q$ z( Z6 K;; and initialize the traffic lights to one setting1 z8 \1 k9 r% {2 ?. v* U% b
to setup-patches5 T/ T" b6 @6 L
;; initialize the patch-owned variables and color the patches to a base-color' Q* O" N5 @: f3 q7 |: W# s' b
ask patches& ]4 f( x7 b7 c* m4 n9 C( L
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& s$ M5 U1 c) n+ _! g set intersection? false' K/ u4 \6 U9 J
set auto? false( t& F1 @( K) N, g
set green-light-up? true
; X2 E- O- A; O set my-row -1
) G2 V. N/ c5 i/ u1 [( O set my-column -15 N& o; m6 y9 ?% a
set my-phase -1
2 G( B4 U( F) l% z: K2 q set pcolor brown + 3: |& Z! h* r# L* I: J# t1 i
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* P J- ]) A" i/ g+ F0 U ;; initialize the global variables that hold patch agentsets4 ]0 H/ F4 p+ s# Q
set roads patches with7 v- M; \$ l) s/ L" N a& S
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' r. b/ R* O x R: r% a9 H
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 s, z3 V' H8 Z6 |9 c set intersections roads with
0 r6 j v; f/ g) \ `1 I# Z4 f [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
$ J' m% _3 [8 Q+ J (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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end2 N$ n/ E+ {: j7 \+ q4 x
其中定义道路的句子,如下所示,是什么意思啊?8 ^) |6 F7 N' K# U, n
set roads patches with
# t& ?: {- r8 `/ j2 E [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! F; Y5 E' x r3 k. v! C: |) L# @
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
4 N4 E" a( Y+ m5 K& y! Q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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