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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。2 E0 F: @* X8 V$ C
netlogo自带的social science--traffic grid这一例子当中,
# d( }1 h9 z) u" N, Y- e( q6 ~globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
7 @7 i( W7 x: T! W& X0 P5 a grid-y-inc ;; the amount of patches in between two roads in the y direction
% B& c9 h& S& L4 w% a acceleration ;; the constant that controls how much a car speeds up or slows down by if/ O+ e, c9 A) c: w) i9 ^/ u
;; it is to accelerate or decelerate
- ]) ?8 s9 \% [! Z2 l) R phase ;; keeps track of the phase$ j$ W" \. g% E, V- Q
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
' b( y4 w/ t+ X# z. B; B1 S5 z current-light ;; the currently selected light
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;; patch agentsets' V) \( U( @% r$ Z) K5 ?
intersections ;; agentset containing the patches that are intersections
- b* D6 ^2 Q4 t" N: F5 E roads ;; agentset containing the patches that are roads
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turtles-own" ~2 d$ \# K. g3 ]5 e
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speed ;; the speed of the turtle
9 H; a+ Y' b+ Z0 s: J up-car? ;; true if the turtle moves downwards and false if it moves to the right& f4 q. b8 p! W4 U, T& ^
wait-time ;; the amount of time since the last time a turtle has moved
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0 A1 l, s% u* e1 c: N) wpatches-own% x! H+ S+ q1 [
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intersection? ;; true if the patch is at the intersection of two roads
+ J2 q+ G$ m; @ _, u, u green-light-up? ;; true if the green light is above the intersection. otherwise, false.
( T9 F: x# b" ~! u5 O/ B M& N ;; false for a non-intersection patches.
) o' l5 G# L! c0 ~7 O. j1 y my-row ;; the row of the intersection counting from the upper left corner of the& h. u# \; U+ h* Q7 i: {. ]8 N- b
;; world. -1 for non-intersection patches.
4 O3 u7 Q, O3 b J/ A) t h- N: P my-column ;; the column of the intersection counting from the upper left corner of the3 c- K8 n: z$ c. v4 }
;; world. -1 for non-intersection patches.
6 _' T$ O- h1 i: P, Q- H my-phase ;; the phase for the intersection. -1 for non-intersection patches.
9 ]' M1 F; \5 E! x( y5 a0 _# W/ c auto? ;; whether or not this intersection will switch automatically.
0 L; y* `' ^$ c) y) D: y+ A ;; false for non-intersection patches.: m$ h( Q& }7 h
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0 ?" y1 W& y" }$ _ E+ X;;;;;;;;;;;;;;;;;;;;;;! ?% M4 R5 w8 j H8 v
;; Setup Procedures ;;
+ d7 |, e; M# Q- Q1 K;;;;;;;;;;;;;;;;;;;;;;
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' B5 y) f6 `; z+ p v$ F! b2 [;; Initialize the display by giving the global and patch variables initial values.
/ M, C: [0 \- ?- m6 [! w;; Create num-cars of turtles if there are enough road patches for one turtle to% _& X" ?+ w* |( t, F# Q
;; be created per road patch. Set up the plots.
% P' k g& c7 {2 }7 J- e( fto setup
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: {. z' ^3 n2 A setup-globals
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;; First we ask the patches to draw themselves and set up a few variables) M8 W( y# e" S/ j) ?: H
setup-patches8 O! G, u8 v' F
make-current one-of intersections& l2 t" P. f, g$ y& |4 e5 d- M
label-current0 [$ Z. Y8 I* N5 Z+ h c) `
$ L) V0 a. w7 }5 G, S* M+ I- B set-default-shape turtles "car"
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- L# q, ?# E+ u2 W- n" A& B if (num-cars > count roads)9 w) L* Z* |/ Z5 z" ]3 E+ Z
[
6 i. N# B+ e& b" {7 u' v, g) w user-message (word "There are too many cars for the amount of "
9 _6 Q# V( b! C* a; r "road. Either increase the amount of roads "
, O" `/ L# [3 M' N "by increasing the GRID-SIZE-X or "
: l1 c3 w. H5 K+ V( N "GRID-SIZE-Y sliders, or decrease the "
& }+ q H, g( d "number of cars by lowering the NUMBER slider.\n"
6 m1 y6 G5 C6 U' [5 b "The setup has stopped.")* I7 f$ F. |5 Z& C+ o
stop1 J3 z6 T! m3 | X+ T+ d) C
]
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& l7 `) ~2 r: A3 ] ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
9 X/ G0 t' C: ]$ J/ I Y6 Y crt num-cars
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setup-cars
. M% t3 v: b) S% ~: ]+ W set-car-color
" ~; O$ d) n& b# X d7 A record-data" @* }3 h4 G! b7 q8 h0 S
]
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;; give the turtles an initial speed
3 }" D- G; \" ?5 a ask turtles [ set-car-speed ]
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reset-ticks
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;; Initialize the global variables to appropriate values0 H$ c B. A! `4 D+ g& S) V
to setup-globals9 C6 Y& j7 `" W& Y; {- i' B0 i! B
set current-light nobody ;; just for now, since there are no lights yet
1 ?0 r% h6 ^4 d K3 ?5 o set phase 01 S, V t1 l) ]* V, c
set num-cars-stopped 0
* ~* j2 `, S$ X) z# K3 F* ^5 s set grid-x-inc world-width / grid-size-x. D0 d- Q+ L& K$ Q
set grid-y-inc world-height / grid-size-y; |8 f# `) H* Q2 i0 ~' _1 i$ c
# w: k" d( `! g+ ^ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary- f& Z/ s0 F3 d- v7 ?
set acceleration 0.099
" x* f- t. I6 g( Q* J) W/ U. Send
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/ I6 U& a# P! C/ w- R: }: V;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
" T; b" Q. ~+ h5 x;; and initialize the traffic lights to one setting
' j. O. l/ s$ }( i/ p9 w4 N% dto setup-patches
+ ?9 Y9 L# ?- r! L ;; initialize the patch-owned variables and color the patches to a base-color! A( W! ?( M u
ask patches% K/ \+ a- S6 h! U, y, ?" n) `' I
[
' h% b* ~4 F3 p( b/ p set intersection? false
4 F4 i, i8 Q" L. G2 K! W% _! {6 k w set auto? false/ j! b w9 L- `) v6 P
set green-light-up? true* r* R. Z3 G9 _% u$ `
set my-row -1; Q' X3 ?1 H% i, a9 \. S6 m& Y( l! q
set my-column -1% H9 a& J+ H2 w' A, |
set my-phase -1
7 u. Z- A& B# J0 Y$ u) y set pcolor brown + 3, r! m7 Y- D! U5 r) P
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& U7 Q; |9 r6 M D% o ;; initialize the global variables that hold patch agentsets
, B4 J9 I2 H' N: T: x set roads patches with
% r# B* a D, t# x7 Q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* J+ t$ U& C% o
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 a& p r O0 f set intersections roads with1 p+ V" W, ~1 E1 H. h- C2 h/ a: F
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
; l/ l* Z8 K% l) s" G (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
+ Z) s" ?. e3 G: ]' Z; \! D setup-intersections
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3 W# s6 n2 Q5 c$ x- g* }其中定义道路的句子,如下所示,是什么意思啊?" u$ R$ N" C' F" Z0 P
set roads patches with
( J4 Q' \; I6 N8 \8 a& A- ^) _ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% D# z5 l6 R* Y- {; J
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) P0 O. L0 i% R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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