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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。) E" u+ ^# T3 O4 }" d
netlogo自带的social science--traffic grid这一例子当中,
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grid-x-inc ;; the amount of patches in between two roads in the x direction
( T& I5 s F; ?3 X+ E grid-y-inc ;; the amount of patches in between two roads in the y direction6 F4 ~ f& q1 { [; j8 e
acceleration ;; the constant that controls how much a car speeds up or slows down by if5 s6 B1 @& z1 n6 [/ k1 Q7 S2 L
;; it is to accelerate or decelerate% [) {; b; @" y, Z& Q. @- G
phase ;; keeps track of the phase( x6 l% E! e2 D
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure2 ~4 x: e; [: a; V( c& b
current-light ;; the currently selected light, A) R( w V# G) A" Z; C: [5 |
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;; patch agentsets
E8 }! k* I) L2 h* u/ s) A. g1 t intersections ;; agentset containing the patches that are intersections
: h; H/ r" A9 Z roads ;; agentset containing the patches that are roads9 ]1 k7 M# O& `: G% l: a4 S. V
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turtles-own* f8 |. [. B4 g; x
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speed ;; the speed of the turtle
( U& P% g5 r. T up-car? ;; true if the turtle moves downwards and false if it moves to the right/ [/ X# ?5 P* X! k7 j
wait-time ;; the amount of time since the last time a turtle has moved
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: @7 Y& I$ Y6 V) X0 ipatches-own
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& Z2 ~0 e2 ]) m! h( Q8 R; _( z1 | intersection? ;; true if the patch is at the intersection of two roads
0 ~( J( j: b3 n green-light-up? ;; true if the green light is above the intersection. otherwise, false.7 z- d3 K$ [1 C
;; false for a non-intersection patches.
+ J0 e l) [3 V J* S my-row ;; the row of the intersection counting from the upper left corner of the- G# n2 E# f+ y, @
;; world. -1 for non-intersection patches.0 Q3 E: s- ?0 P( h8 Z
my-column ;; the column of the intersection counting from the upper left corner of the
4 b: q7 M$ z8 N1 X& d) X' z, K0 M3 P ;; world. -1 for non-intersection patches.
, S: B1 W$ }; W/ M my-phase ;; the phase for the intersection. -1 for non-intersection patches.( u' w; V7 j6 Z* J
auto? ;; whether or not this intersection will switch automatically.
* ?/ {+ L* M# ]# e: D" R" K ;; false for non-intersection patches.1 L( e- t- C0 y$ g& m
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& m' L1 k; g( };;;;;;;;;;;;;;;;;;;;;;
* i2 U# \8 {; L8 ] r;; Setup Procedures ;;4 n0 j, J" q, t d. s' V9 d
;;;;;;;;;;;;;;;;;;;;;;! y/ f) N' M$ E! o
& L+ c) }# M( e;; Initialize the display by giving the global and patch variables initial values.# m) p/ _6 H$ z+ ~( O
;; Create num-cars of turtles if there are enough road patches for one turtle to* y9 {( }1 u' z6 g- k& f: H
;; be created per road patch. Set up the plots.
$ S; v. h/ a! f+ Q9 xto setup
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setup-globals
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N |" G( R/ t! R4 C ;; First we ask the patches to draw themselves and set up a few variables
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make-current one-of intersections
* s W5 f0 H0 o0 _ label-current
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set-default-shape turtles "car"1 ^% u( e4 Q$ i4 C- R% K7 W
9 ^+ y( y, W& [5 F) i9 v% \ } if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
) O3 _* G7 a9 y) K. X3 M5 z7 L" W "road. Either increase the amount of roads ": z1 j5 X8 s r; Q
"by increasing the GRID-SIZE-X or "% Y& N: ]) S B* k4 I; W
"GRID-SIZE-Y sliders, or decrease the "
* S" D, D K! ]; \; J. U. ? "number of cars by lowering the NUMBER slider.\n"4 t9 h3 o" ]0 w5 S) [
"The setup has stopped.")5 H7 a7 |: T$ n$ \4 Q
stop [% c: a$ [5 Z5 K& X
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
5 Y: h+ C8 Q1 H+ p crt num-cars
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5 O8 T2 o. F' t0 O: a setup-cars
, M) y, a6 d2 [9 j5 s; z set-car-color
6 {3 D4 H; m" _ record-data- n# ~: ~( o$ w) ~/ L0 |
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3 q/ ^3 g; U. w. G# w, ] ;; give the turtles an initial speed' _1 V) W' x* M9 ~; t8 g' X+ U
ask turtles [ set-car-speed ]/ F: [" d' G% X- y
: B/ s- ?5 O. I# @ reset-ticks
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7 E# p2 s5 q) g/ A/ Q6 I4 M;; Initialize the global variables to appropriate values
2 z1 d2 |. v8 c L4 \6 Xto setup-globals
9 _! }! r3 `0 I, o N4 ^! R) Z6 k set current-light nobody ;; just for now, since there are no lights yet# e: K2 r5 K Z2 j* B _2 \
set phase 0 m7 y5 m# C2 _8 K4 \# Y
set num-cars-stopped 0
! ]3 A% l2 O, n: b1 d) x& H8 r; y6 u set grid-x-inc world-width / grid-size-x
" o3 z# l' }( f4 u, W- o" ? set grid-y-inc world-height / grid-size-y
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R: H8 Z* B/ l. c- o5 ~) A ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
+ ]& c& Q7 X/ {1 x8 J" `( b, d set acceleration 0.0999 p( {' Z6 C% R6 {* ?
end1 e) c: L2 T% ?9 @, i
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,- f1 }0 U7 B. T5 h2 ^4 V
;; and initialize the traffic lights to one setting
# @0 R1 B4 n0 h% K8 xto setup-patches
% k4 X, p* q2 M/ V/ l4 d ;; initialize the patch-owned variables and color the patches to a base-color
1 z `/ i# A7 I) M. S$ ` ask patches
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set intersection? false) R5 G7 I7 X$ p- J' w3 ?% w6 }
set auto? false2 _, g* z: k# r6 `3 Q
set green-light-up? true
; V G- ^+ d- r2 d2 d: C set my-row -1
+ P( ?$ ?/ [! [& l1 a set my-column -1
7 _* @( Q$ N" z# \ set my-phase -1
5 v! `3 V2 A5 @9 u m& q6 [! n set pcolor brown + 3- K) }4 a5 X" o: l0 B! I0 r' N
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9 }9 y9 V; W; }8 H- q ;; initialize the global variables that hold patch agentsets
y7 |9 l7 c# j( }2 e8 D' a8 H set roads patches with: q( s5 `/ ?" |- M
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ T( l- g/ d+ _/ `8 [
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# _7 B* s/ Z! T7 |2 p" l set intersections roads with* v5 ^% F* V' Q5 |5 ]- c% U
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
7 Z7 Z, w. Q6 l7 G (floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 O9 s9 B @2 N* G0 {9 h5 S1 J
3 r* M7 C' T" l8 `7 {7 ] ask roads [ set pcolor white ]
. C {: ~: \* D3 ?- \ g setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?
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/ E$ F& I! `6 N7 s1 o6 B [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
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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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