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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。
5 X/ W. K* ]5 ?/ b& u1 znetlogo自带的social science--traffic grid这一例子当中,- ]4 V7 Q$ A' W% C7 x; I5 ^
globals, ^# w; i. i4 w' u8 H* w" C3 E+ ^ H
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grid-x-inc ;; the amount of patches in between two roads in the x direction
0 D, g6 _' X1 k) u6 U grid-y-inc ;; the amount of patches in between two roads in the y direction) s0 {+ c( |( Z" q6 {3 i+ N9 a
acceleration ;; the constant that controls how much a car speeds up or slows down by if
3 Y& j! G: S, t& q4 ]. _ ;; it is to accelerate or decelerate
* G" y) [6 m* o0 n* O phase ;; keeps track of the phase$ ^6 Q) ]( b- V# z& r9 k
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
4 j# m1 b2 ^' U, z current-light ;; the currently selected light
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;; patch agentsets/ d6 k, ]* ^+ k S+ ^
intersections ;; agentset containing the patches that are intersections$ f7 Y1 n# k/ I
roads ;; agentset containing the patches that are roads( r# Q( ~& Y Q
]
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turtles-own* ~) x6 E2 r( e3 q; T2 W/ q# G
[
8 R$ c! P3 Q6 q9 Q* d speed ;; the speed of the turtle
+ F; \* @% L) ` up-car? ;; true if the turtle moves downwards and false if it moves to the right
' h( _7 W$ L R+ P wait-time ;; the amount of time since the last time a turtle has moved: f" u7 H3 m, {% x4 a" A
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patches-own l0 v. ^7 o! w, @) H- b
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intersection? ;; true if the patch is at the intersection of two roads- H/ C) K2 c- ^# g3 i- u9 ^
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
: }5 N1 T3 c$ j6 T' Q% I: u) k: B ;; false for a non-intersection patches.
7 w! r0 U9 I( z4 H, |; F- t my-row ;; the row of the intersection counting from the upper left corner of the/ V. {" _% V& w4 {
;; world. -1 for non-intersection patches.8 m5 l) J# n" [+ k- w. q
my-column ;; the column of the intersection counting from the upper left corner of the' E# D. c+ U% ]
;; world. -1 for non-intersection patches.
! c8 M* X0 ?8 c. _( v my-phase ;; the phase for the intersection. -1 for non-intersection patches.1 U7 Z( [8 E4 n! t _
auto? ;; whether or not this intersection will switch automatically.( `/ [; M8 ?$ R4 V' l% i
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;( N& `! D: F- ?6 p4 @- a$ N$ \, F; Q9 F
;; Setup Procedures ;;5 @$ |0 A: \, u6 q
;;;;;;;;;;;;;;;;;;;;;;
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9 Y7 N U" n: R% Q1 a0 R, C+ |: `;; Initialize the display by giving the global and patch variables initial values.
1 w* f+ @9 i8 S* t% b" z;; Create num-cars of turtles if there are enough road patches for one turtle to+ T8 Y: Z! O, ^- }9 R' [$ |7 ?9 T
;; be created per road patch. Set up the plots.1 u6 w) P: z5 `+ z
to setup9 k- j3 Y8 l2 D4 U$ f+ R1 D
ca
8 ?9 E3 t" Z3 G, D7 [7 {( @$ H setup-globals5 i+ i' R& w- a8 _4 r
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;; First we ask the patches to draw themselves and set up a few variables
" p5 `/ {/ e( w3 V$ I O! H! T setup-patches
9 f) z$ ~( g8 {4 ^4 @6 X( { make-current one-of intersections
+ P. Y# r9 Y+ o0 R" Z label-current( Y8 Y9 C3 @* j3 U# w
" M, N& O+ j, d1 {& b' x3 L, M set-default-shape turtles "car"6 U! w. M6 s+ ~; P6 c! J, ~
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
' [' m0 b/ x6 Q5 O "road. Either increase the amount of roads "/ T& b$ r' N# b! G
"by increasing the GRID-SIZE-X or "
4 Z2 b* j& T5 R7 ?7 j* C; l "GRID-SIZE-Y sliders, or decrease the ": ]# u" ~" o/ E2 E
"number of cars by lowering the NUMBER slider.\n"! B/ g# S y1 x. s9 Y. R
"The setup has stopped.")4 C& M& z& s$ q( H) t5 |7 E
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
0 e) p1 d: ]5 H) r- R7 V crt num-cars) D$ Q' t* X3 S; Q# j: D2 i
[
0 T8 g& d0 T# b: C$ d, Q setup-cars
6 t$ O, \) K4 ?8 S' E/ t: _- E3 L set-car-color( o6 A! ?8 _! e# h
record-data
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;; give the turtles an initial speed
& H% ~0 R! k0 c- ] ask turtles [ set-car-speed ]
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reset-ticks
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- o; r0 u# r" |$ r5 n;; Initialize the global variables to appropriate values
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8 o& k. G' f1 X4 m( t1 c; V set current-light nobody ;; just for now, since there are no lights yet
. B( p, t" P9 M set phase 0
0 s1 i7 |4 ^% ]; b5 d set num-cars-stopped 03 C- V" I' M! f Y
set grid-x-inc world-width / grid-size-x! Y" l8 {3 Q# ^ `
set grid-y-inc world-height / grid-size-y9 K( l8 ~3 t t# D: s1 b- {9 A
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
+ m% U' j" f8 S) R set acceleration 0.099- t4 J: I! M- _+ ~6 U
end2 m, l [6 Y) r8 s/ |( K
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,$ F/ O4 E/ M+ B; n0 k: _
;; and initialize the traffic lights to one setting
" F+ r2 `, {. d' U7 Jto setup-patches& F* | ^8 l$ m6 k" d. M$ `
;; initialize the patch-owned variables and color the patches to a base-color1 f* \* \$ v& Z) e0 ]: A. Q
ask patches, l* k; ~; v) Y) D: @* {
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set intersection? false+ H9 d1 e. D7 B
set auto? false+ v: A' f/ i8 \# k( H5 n
set green-light-up? true
, O) r$ o' B5 j4 I# A set my-row -18 P8 f- W( L7 G8 M5 X4 M; y4 s: U
set my-column -1
. W3 T# e8 h( v- D& q/ x+ c" v7 b set my-phase -1
% x/ ~9 z# h6 N* h( m0 N set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets! V1 `9 c u9 ]" H
set roads patches with
# Q) m0 Q. u# z' h$ o% u4 ?1 R [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or9 H$ w1 x+ S1 x7 a) j( q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]# X; @# L: d4 J
set intersections roads with. M, Q& v3 B8 J( f% E8 ?& g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and+ T) Z8 x. A+ @8 D6 h. L
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]( Y$ j U$ v. ]& t$ L8 |0 n( Z
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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?. T* z* N3 K' j1 N9 W; y9 y. Y
set roads patches with/ W. }2 h2 N6 h: n# C; E; e% k& h
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; [# D$ M( |; n1 `0 T (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
! c# ~* V( m8 ]) q( L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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