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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。) u; t* v _# Z/ f6 q: I
netlogo自带的social science--traffic grid这一例子当中,: u! z" ]. z5 A3 ^
globals
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* X- ]( q! y7 C+ r% F7 Y r grid-x-inc ;; the amount of patches in between two roads in the x direction: e4 _+ _4 Y4 |/ L' F' F
grid-y-inc ;; the amount of patches in between two roads in the y direction( Q% K; K( P! {+ b
acceleration ;; the constant that controls how much a car speeds up or slows down by if
$ k$ {$ [8 @7 w8 B0 I8 `7 `5 c ;; it is to accelerate or decelerate; e1 q$ Q0 v: t' W4 J
phase ;; keeps track of the phase/ v0 ^4 u' T! S, l1 t
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure) J* h- n" F, w( F: n
current-light ;; the currently selected light7 q) h- l9 a3 j: [2 w- Q: Q6 z
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;; patch agentsets9 v7 Z3 `* X# j
intersections ;; agentset containing the patches that are intersections
3 P9 t3 |) l% N1 R9 e& k roads ;; agentset containing the patches that are roads
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6 ]1 `: }8 _6 ]- m1 ?turtles-own
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speed ;; the speed of the turtle5 t- ] s) j3 _, {& \
up-car? ;; true if the turtle moves downwards and false if it moves to the right, G7 K8 l5 W$ Z' ~ i+ E
wait-time ;; the amount of time since the last time a turtle has moved! O6 |5 `2 P: t0 P- I, i7 D
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patches-own6 i$ P; u& }) H6 H$ |% k, U
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intersection? ;; true if the patch is at the intersection of two roads5 }+ O8 ?' c" l/ `& D
green-light-up? ;; true if the green light is above the intersection. otherwise, false.* I- o: h7 Y8 q2 n
;; false for a non-intersection patches.2 ^ o3 c+ l% M7 _+ j( E
my-row ;; the row of the intersection counting from the upper left corner of the# u% ^. k4 ^7 U7 P9 l
;; world. -1 for non-intersection patches.
# B* `& |. r, l ~( P8 t0 o my-column ;; the column of the intersection counting from the upper left corner of the) }- ` n( L7 n* y. I/ c
;; world. -1 for non-intersection patches.
! y0 |, P' j% O5 B& ]3 l my-phase ;; the phase for the intersection. -1 for non-intersection patches.# ?& O0 w& B# M% `1 u8 D& `
auto? ;; whether or not this intersection will switch automatically.
2 p! f# [ N) G8 t ;; false for non-intersection patches.' \' ^! r) w, L6 Y
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; N$ `% {* p0 ?# ^9 ^0 g;;;;;;;;;;;;;;;;;;;;;;0 Q8 F, x, ` n( L' ^* d9 U) B
;; Setup Procedures ;;& s, A+ q$ f7 S- W' Z
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1 ?0 `& |( W* g( G;; Initialize the display by giving the global and patch variables initial values.
~& i1 _9 D# I;; Create num-cars of turtles if there are enough road patches for one turtle to) B( G Q m4 _0 q9 m# p
;; be created per road patch. Set up the plots.
$ o- G; A! a) U% e, |1 X! ~to setup# K: @- {! q& d+ N! ?. `
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setup-globals+ ~( z, C6 i" k0 ^1 B! D. i: ^
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;; First we ask the patches to draw themselves and set up a few variables O( W8 ~# {) ~4 N1 O; v( x
setup-patches
# I( u+ E4 C- S; _ make-current one-of intersections, {8 }# K1 c$ T$ N: Y* g
label-current
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# s3 T4 }7 U1 m6 V( r4 ? set-default-shape turtles "car"
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" b4 a9 `2 p' K; b+ R if (num-cars > count roads)1 q0 g) l1 S4 K$ ^) D) w
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user-message (word "There are too many cars for the amount of "
% G" M" S' Z+ a "road. Either increase the amount of roads "
4 R: c; B6 L5 I "by increasing the GRID-SIZE-X or "
6 ^1 R: p$ G7 U "GRID-SIZE-Y sliders, or decrease the "2 k$ G! U! z4 W7 o+ E7 Y+ n/ j
"number of cars by lowering the NUMBER slider.\n"0 ^# y, Q, s% H) f7 x
"The setup has stopped.")
3 I; K- }7 a" l6 {; m5 z stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
- M$ e2 u' l4 V; V$ D crt num-cars# c1 e$ l9 }4 u) ?. I
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setup-cars: B( d4 {' f8 z' d; ^ j3 l
set-car-color
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2 j8 a. c8 s8 z4 b3 W; a ;; give the turtles an initial speed
8 ^+ T$ a; [, G) { ask turtles [ set-car-speed ]
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reset-ticks
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& w7 R' [$ X9 F;; Initialize the global variables to appropriate values
/ N( x( X. v( F* C' P* Jto setup-globals) R$ @$ g$ V5 G' A9 ^ ^, Z
set current-light nobody ;; just for now, since there are no lights yet( R" W- A5 y# [7 ^
set phase 0' d4 v1 k/ o: c3 t `5 \: y
set num-cars-stopped 0* l5 e/ h: X# z2 a V0 m7 M8 T! D
set grid-x-inc world-width / grid-size-x) k# u* F1 G; N6 b! w- O
set grid-y-inc world-height / grid-size-y( `* R9 N% k+ y& @' @9 M0 F4 I
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
" y/ V9 e5 k1 b% z& l set acceleration 0.099( k9 L$ f" I1 F& r/ ?
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,: D3 ^9 ~) {$ x5 W7 ^ V5 U0 y
;; and initialize the traffic lights to one setting
, a3 L$ B, K; h3 S% j+ n Q, [, w! dto setup-patches- P& q' a1 a" w/ @: I& f
;; initialize the patch-owned variables and color the patches to a base-color
! Z) A- S5 b) W0 g- k9 ~% ~; Q ask patches
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set intersection? false
) N- X% J; P4 |$ R, l set auto? false
& d7 {% u4 }, _. Q! H set green-light-up? true
" j" `9 |1 F, }1 O4 v set my-row -1
9 U/ U1 f h" t8 o5 f7 q set my-column -1
6 x/ d3 }4 A+ c set my-phase -1
5 F6 i3 V! F6 s2 |0 ~: f set pcolor brown + 3
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+ l$ B( L8 U% W* q2 @8 {! \( ` ;; initialize the global variables that hold patch agentsets
0 T: ]6 C4 Y% L2 A" E c0 t& ? set roads patches with& | l4 E( h0 p% ^/ A5 H1 J* ] ]
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 O9 _1 S/ K A. T (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 E& T1 J: C* ]) N. z
set intersections roads with
8 [6 G4 q( Q! A" m$ A4 b8 x7 o* E [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and& I% y$ { e- j4 s; \" G
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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2 k6 B H' a" j8 q# B, `. Z$ f ask roads [ set pcolor white ]) B' H# P( K" P) c" ]' _
setup-intersections
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4 L4 E; f5 T$ ~" v4 z. k$ G其中定义道路的句子,如下所示,是什么意思啊?2 V1 [1 L$ z7 A. m8 F
set roads patches with! m/ |6 M8 k$ P- m6 s! I
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
9 g- y' H6 C$ k. b8 A! d$ k (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; _, S" c& T7 c7 v: _5 S" b1 c; `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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