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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。7 O! P" p- _, r+ K& [7 ]8 r
netlogo自带的social science--traffic grid这一例子当中,
}. u, f/ [/ L. R' e3 ^* Pglobals
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F% Z. n9 |9 e' }$ \5 ^ grid-x-inc ;; the amount of patches in between two roads in the x direction9 d/ t8 J' ?9 F
grid-y-inc ;; the amount of patches in between two roads in the y direction! c1 K3 A. a1 A9 {, I9 n4 n
acceleration ;; the constant that controls how much a car speeds up or slows down by if( \3 D/ f" w% z, R- P8 p1 Y( [, ?
;; it is to accelerate or decelerate" j4 n3 E4 y Z! |
phase ;; keeps track of the phase) }; O+ {$ M( H! }$ K; a
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure% ^" M9 U8 r. q0 F4 V# z( }
current-light ;; the currently selected light% n1 S+ b" U* r! L: L1 C8 j
; q/ u$ v+ ]+ W* V5 }$ Q ;; patch agentsets
6 g/ ^. j( L* A. X, \9 W4 G2 n intersections ;; agentset containing the patches that are intersections
& u9 C9 L1 z) n* E" V+ p% b# b6 y5 p roads ;; agentset containing the patches that are roads: V/ \' g1 q3 M* ]3 J* p3 c; z/ k
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turtles-own
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) {+ ~8 U& E0 Z: g9 l speed ;; the speed of the turtle/ \8 E5 Q' I& x" C
up-car? ;; true if the turtle moves downwards and false if it moves to the right
! J1 b: n( w3 v" S wait-time ;; the amount of time since the last time a turtle has moved- Q6 i* K3 f9 p
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patches-own% o8 s+ l, c* v p: A
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intersection? ;; true if the patch is at the intersection of two roads! J) [) e( c" `- w- S& W
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
" T& ^2 [& n' \$ ~' N. R' @, B* H ;; false for a non-intersection patches.
7 W4 P a. ~& Z/ u$ z. g my-row ;; the row of the intersection counting from the upper left corner of the
( L& A/ ?8 k& A* D/ t' P# F ;; world. -1 for non-intersection patches./ k7 q6 V5 g* T4 c
my-column ;; the column of the intersection counting from the upper left corner of the
' y9 H) y; h; x( _" Z ;; world. -1 for non-intersection patches.1 ], l" Q! m8 A5 T- X
my-phase ;; the phase for the intersection. -1 for non-intersection patches.- s' W. `4 R9 t( W" g* T: C" A
auto? ;; whether or not this intersection will switch automatically.' `8 R7 o9 H* `
;; false for non-intersection patches.
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# ^+ Z. U. d Q/ U9 N;;;;;;;;;;;;;;;;;;;;;;
+ I/ h$ k* Y+ ^1 q;; Setup Procedures ;;1 T9 }( p3 a4 h1 |/ V8 C) y
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;; Initialize the display by giving the global and patch variables initial values.3 |' B" Q8 q I5 O4 H
;; Create num-cars of turtles if there are enough road patches for one turtle to
* w4 T- |( [' x, }: I;; be created per road patch. Set up the plots.
, k' h% n7 }' G6 eto setup
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, `. K, Q' S& A! [ setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
5 g% ?2 Y- a' [1 v setup-patches
# q7 Q- \2 K3 i$ ^" P# _ make-current one-of intersections
# X3 f& K8 x7 p6 f0 t7 L label-current. f1 Q1 \) l8 t0 V
$ }4 j0 j3 |* d# p set-default-shape turtles "car"
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if (num-cars > count roads)' K, f! Z& R2 [9 J
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user-message (word "There are too many cars for the amount of "( v9 J, D( t6 [9 V5 u; Q5 b
"road. Either increase the amount of roads ") n: r" B) D8 H: X, r9 X
"by increasing the GRID-SIZE-X or "$ O) ^! H O4 h7 E. _/ ^4 v
"GRID-SIZE-Y sliders, or decrease the "
$ E x& j" ?! h* J" y/ H "number of cars by lowering the NUMBER slider.\n"
& R. V4 {6 L. G* D6 A% I; `/ S "The setup has stopped.")
# G9 t+ d+ l7 [/ J' V9 @ stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
3 v& o& q* a! K* K/ I0 I5 Z7 } crt num-cars
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2 L2 o4 j& D- T" L+ \; q setup-cars
! T1 H. l% l9 W, D/ u set-car-color
- Q. o7 H' N* ~% D) f) k& { record-data
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;; give the turtles an initial speed
- Z1 W2 m9 E! v" m; F0 w- T3 p ask turtles [ set-car-speed ]
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. a3 _/ N. M( `- L8 y reset-ticks
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
9 Q/ `: U9 O7 ]0 k set phase 06 l! w$ D0 M. x1 r! i
set num-cars-stopped 0# v4 }0 e. j- }5 x5 A
set grid-x-inc world-width / grid-size-x& h" B$ I+ _+ W/ b; Z! I& k
set grid-y-inc world-height / grid-size-y% i. T4 v. p# Y, ]
3 L+ j2 y5 K/ Q8 }: ?3 u1 N ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
* R5 L6 A$ H+ m( [5 y( h. j set acceleration 0.099; Q, q, s R% C- ^
end; a3 X1 X: c+ e* k) J; t% [) Y3 ]
' l$ I3 Q; o" [8 u6 k2 S: O# w;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
; Z. H7 i8 _, ]0 H9 b;; and initialize the traffic lights to one setting1 j$ e% ?, j8 t: C# O4 i
to setup-patches& C. D5 g% N" |3 Q
;; initialize the patch-owned variables and color the patches to a base-color& } w. ]1 }" i" G$ Y
ask patches
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set intersection? false' |2 z4 A2 {. t$ I+ K! l* G1 x" B
set auto? false4 q, w( w! @ q `3 N5 U
set green-light-up? true
4 F9 k4 r8 h8 K! p8 f/ f1 E set my-row -1
% q! I3 O: L5 }" [6 E: q set my-column -1+ N6 V0 G3 D; n/ V* |" j
set my-phase -1' G. F, H2 k" d$ z7 Z- E1 D6 d( y
set pcolor brown + 3
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* e1 ^$ I a M5 |3 Z* _ ;; initialize the global variables that hold patch agentsets
" } X9 P1 i+ D( k6 f! ` set roads patches with
3 l9 D* R% q: A [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 t* L! L2 p2 |) F z& r: ]
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]* ^# y: F4 d4 v0 b2 e7 J
set intersections roads with, o4 i+ ^( k/ A* v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and: t9 H# \2 o% S2 N+ I' w
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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: P: }. z! W6 ? ask roads [ set pcolor white ]; N) ~2 }6 n) C3 @& s# B" V
setup-intersections
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6 r8 P# v- z8 n其中定义道路的句子,如下所示,是什么意思啊?/ q, N3 ^6 }1 R9 Q
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 _% p9 m( h8 y4 m9 p% P
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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