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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。# ]- m$ \* I$ H4 |
netlogo自带的social science--traffic grid这一例子当中,
1 Q" p4 E3 b \globals9 Q/ U% |2 z+ R" B
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grid-x-inc ;; the amount of patches in between two roads in the x direction
! ]' P8 Y5 Q% d, T |- B grid-y-inc ;; the amount of patches in between two roads in the y direction
* v" {) _: }$ U! G* N acceleration ;; the constant that controls how much a car speeds up or slows down by if
2 n8 u$ A6 j9 w6 F& s. z# ]: l ;; it is to accelerate or decelerate
# \4 u8 D" s! r$ k' b" W, Z/ x | phase ;; keeps track of the phase$ {$ A) q* F0 v& c
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure3 K& o: }: t2 D5 V2 d3 {( q% \
current-light ;; the currently selected light
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;; patch agentsets" V( d( k g% Q; g
intersections ;; agentset containing the patches that are intersections# t* x! T* f, K5 R" k; n$ _/ n
roads ;; agentset containing the patches that are roads
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, j9 c9 y# O# `$ i; C! pturtles-own
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6 Y" q( D- q9 r5 Q. P2 l# ?. p speed ;; the speed of the turtle6 e, e2 Z3 f' ]' f8 b
up-car? ;; true if the turtle moves downwards and false if it moves to the right
% m K1 A! A/ I. t3 X/ b wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads" H! `) k, V- a; ^" z( a
green-light-up? ;; true if the green light is above the intersection. otherwise, false.5 s, F( r: a- v0 V* L; X Z) A
;; false for a non-intersection patches.
* H4 l( f5 U; Z6 v& H& T* Y6 p my-row ;; the row of the intersection counting from the upper left corner of the
& S8 s6 }6 [, E7 x6 I$ g, I. Q ;; world. -1 for non-intersection patches.
4 @. [5 A! c' L, }) \; A& c my-column ;; the column of the intersection counting from the upper left corner of the+ h, U% }! Q0 W! [4 R0 j5 d; u' E! J
;; world. -1 for non-intersection patches.: m# Y8 B! _+ ~3 o# C
my-phase ;; the phase for the intersection. -1 for non-intersection patches.2 Z6 r( p$ P; m' \" K
auto? ;; whether or not this intersection will switch automatically.$ s& J3 S9 `3 k/ j% U
;; false for non-intersection patches.
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/ ~) ]" K/ c) F;;;;;;;;;;;;;;;;;;;;;;6 h! `* R- i( P( i0 e
;; Setup Procedures ;;
2 f+ j0 l5 \: L) c9 Z;;;;;;;;;;;;;;;;;;;;;;
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2 [% M8 [+ W; o6 S0 ^9 r' v;; Initialize the display by giving the global and patch variables initial values./ y. y. A+ D2 A- w' X7 i) X" d
;; Create num-cars of turtles if there are enough road patches for one turtle to+ u0 X& H( p7 Y
;; be created per road patch. Set up the plots.
3 n: I I1 D) ]! N# Ito setup$ X- [0 F) \2 A$ a
ca
2 q# O6 G% t' D. e9 X T setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
7 Y7 u) p+ ^3 F& l setup-patches" D+ u. L0 r- l N6 Y
make-current one-of intersections) s1 a0 D) D& t- k' ?$ c7 l/ ^
label-current1 `7 g7 s: S1 d# k1 `: s
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set-default-shape turtles "car"
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& {( B1 S+ b7 A2 ]8 {# ^7 L if (num-cars > count roads)& A- P/ j2 a( n
[
+ G/ Q4 v% Q/ k user-message (word "There are too many cars for the amount of "
: L ] D& i/ O1 o2 F "road. Either increase the amount of roads "
5 _, S) u5 i9 w "by increasing the GRID-SIZE-X or "
& u9 G' C+ L8 F/ l "GRID-SIZE-Y sliders, or decrease the "' M' ?" ]) X3 n9 Q2 A0 n, R+ m
"number of cars by lowering the NUMBER slider.\n"
! O, Z; w8 X% o5 z "The setup has stopped.")
/ w9 R- `. O% v% e I7 e. w stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
' t# e5 x0 O) [6 w" s. P) { crt num-cars
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setup-cars
/ d% m) m* c @6 J6 {6 h set-car-color" [ _+ v2 F: R* X" q7 P
record-data
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+ T) v0 K/ S& s4 b. f ;; give the turtles an initial speed
! T; s+ C0 J$ Y! g ask turtles [ set-car-speed ]" h1 C8 P$ n- l( S- i$ S
j; K* v$ V7 H, f P/ d5 s. Y+ c reset-ticks
3 m6 r E4 u2 R- u7 @" E; {3 fend
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% W4 P8 Z/ }# o;; Initialize the global variables to appropriate values4 l" ~" N/ L% ^9 ]: J6 i" P' J
to setup-globals+ k- }. r( ~0 m
set current-light nobody ;; just for now, since there are no lights yet
) s, e+ r8 d6 @ M" m; y p set phase 0
3 @1 P1 B. C# V set num-cars-stopped 0
]( \/ h- I, a1 y9 n$ N6 ^% C set grid-x-inc world-width / grid-size-x
7 ]7 w8 n! a4 i. n* v: e, I1 A7 d, N set grid-y-inc world-height / grid-size-y% o- \" n) E2 P" m V1 {
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary) O# `* b3 Q9 S
set acceleration 0.099
) |$ n2 ~6 _' S5 J9 Tend! A, r/ c) g, Q+ b1 a7 x/ v
( h; E" x5 Y6 N& U5 C& P, ?5 t- t;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
+ c" \8 l2 ? s+ u;; and initialize the traffic lights to one setting. C! f( s& I; x/ E8 }' Z$ X, M
to setup-patches
# M* Y+ u/ m$ s& L# V# j ;; initialize the patch-owned variables and color the patches to a base-color
/ b6 c( J) w, ^, r- ~ ask patches
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set intersection? false& y* f) a" `3 x( |5 _, i
set auto? false
+ W6 X0 \0 D. K1 m# w6 _- z set green-light-up? true9 U: I' |/ f. M1 r: g
set my-row -1
. W9 R6 O" r0 m4 j5 X1 p set my-column -1
, a, N. ?# p8 O1 s9 k( l4 h: t# ~ set my-phase -13 O8 }! _' g, ^4 p" K% k3 i& {3 C
set pcolor brown + 3; I Y B. c; u9 T- m
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# S& ^1 K- I4 N1 \ ;; initialize the global variables that hold patch agentsets
! |6 Z7 K, ~ L; W, z* x( y% Q set roads patches with
. X4 F( \4 e! E4 k. |8 N4 h5 ~ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* U4 d4 Y6 l1 ^+ N# K7 u u2 l" S
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% {( N6 d, R1 E- n" M3 A) ?# X2 ~ set intersections roads with
- B( N& b, p3 t) p" M- ^ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and- ^/ |; E# y/ q% E
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]" v9 U0 o% [& @) V2 u5 x8 O R* M
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ask roads [ set pcolor white ]
: F+ S0 O! P6 } Y setup-intersections% e, z6 |9 _5 Q- W
end
8 T; _( \* x2 p其中定义道路的句子,如下所示,是什么意思啊?* A; C/ I2 X8 W' ~, u4 ]" ^
set roads patches with
4 ~ i' t# Y2 S* V6 E& ] [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or `1 H- A. U" k# E8 C$ K5 k
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' \* r2 ^: ^( l2 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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