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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。. {3 w& ^( p0 h% r, [
netlogo自带的social science--traffic grid这一例子当中,9 h" b; Q, U1 S H: [' p2 f# d5 {
globals9 _& q7 h+ g6 P6 P! F3 J. Z( P
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& M; s; V( y. y/ g: g8 R0 t& } grid-x-inc ;; the amount of patches in between two roads in the x direction6 J3 }- R+ e* g& ]) A5 P
grid-y-inc ;; the amount of patches in between two roads in the y direction3 U: \; @, B) _" T
acceleration ;; the constant that controls how much a car speeds up or slows down by if8 u% P& Q4 y4 f5 I
;; it is to accelerate or decelerate
]; W: J7 C N6 r1 q5 X phase ;; keeps track of the phase
4 }# [5 S$ |( o( A& O7 {& C num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure% G: X7 w5 v1 O1 z# W- T; Q
current-light ;; the currently selected light+ I( |$ |' ^* m, U: r* N) B' N/ q
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;; patch agentsets
& H3 \* c9 m g3 a$ ^ intersections ;; agentset containing the patches that are intersections( S1 A/ V. W# @9 c
roads ;; agentset containing the patches that are roads
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! y y( _" a( k* [" hturtles-own4 ^6 F X5 ^+ L1 p' e6 {
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speed ;; the speed of the turtle% c0 U4 {' Q/ q- b4 |
up-car? ;; true if the turtle moves downwards and false if it moves to the right
5 Y0 Z8 Y& ^0 a2 U wait-time ;; the amount of time since the last time a turtle has moved: H U0 ~4 t* f x2 B0 g5 o
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
. k7 |6 r* U5 V9 j' C) b; E H j+ a green-light-up? ;; true if the green light is above the intersection. otherwise, false.
+ s2 f. ]- Y. F5 b1 E' ` ;; false for a non-intersection patches.
8 S6 u. }, P1 B( O3 }. E0 T- } my-row ;; the row of the intersection counting from the upper left corner of the; M* q" w; P$ [& [
;; world. -1 for non-intersection patches.& f/ z, w$ \' I6 R# h
my-column ;; the column of the intersection counting from the upper left corner of the
& L+ y& u9 A! q# I. a4 J! X ;; world. -1 for non-intersection patches.8 I) m7 c: H/ I" F
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
( A6 E( |3 h: q2 P1 n% t$ e/ h auto? ;; whether or not this intersection will switch automatically." S+ F* b: j+ R
;; false for non-intersection patches.9 o6 ?7 n; O0 L
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;;;;;;;;;;;;;;;;;;;;;;# p6 Y. F2 ?, S1 L6 d9 ^
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
/ B) L: c9 A3 X+ M* O;; Create num-cars of turtles if there are enough road patches for one turtle to+ b, l$ ^4 u5 ?/ |! Y% J1 J
;; be created per road patch. Set up the plots.& n! o4 V' f" S& I/ T
to setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
* d, h% g$ x$ y setup-patches' d4 }( m$ p. t
make-current one-of intersections
' p1 c& f% C0 N0 I' y label-current+ E5 ~/ [, @; S% x4 [6 Q
3 p* L9 W& d1 J; X set-default-shape turtles "car"4 P, u! B6 i4 o# h
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if (num-cars > count roads)& J! }9 d k- ~' |
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* [1 W' X7 j; o, }' w" X; Q user-message (word "There are too many cars for the amount of "
- ]* \8 \8 L, R% ~; o( J "road. Either increase the amount of roads "
8 ~8 S; A5 V0 ^$ o% h "by increasing the GRID-SIZE-X or "
0 F2 l2 c2 J1 V( H9 {9 P4 r' Q. C "GRID-SIZE-Y sliders, or decrease the "
3 r$ K: ^9 U0 Y! l+ g' i+ {4 C6 F "number of cars by lowering the NUMBER slider.\n" O# O, R2 v- e& w
"The setup has stopped.")
6 _2 m+ o9 _. u! O- I/ g/ d+ d2 C stop
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" |1 A b8 G: [& \# B: F! |1 g/ c ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color4 V" \" h2 U+ e
crt num-cars& m/ ?' _4 r4 i0 p
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/ W2 i4 Q- _3 I, @: z' X, V) \5 E setup-cars& y: D2 f m' y' D2 v, @
set-car-color
8 {- k/ ?7 z7 f" j" Q7 Y" D record-data4 Y1 u9 G0 @ y Y& |
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% H: s% g. o6 ?* j ;; give the turtles an initial speed" r2 O% V- W; D$ J0 {2 T
ask turtles [ set-car-speed ]
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8 T1 m6 D1 i5 g' g- N" B* l reset-ticks
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0 M8 L9 v# T' n7 ]" ^4 X7 i' h;; Initialize the global variables to appropriate values+ P& ?' y% a. F% F( V
to setup-globals
2 W6 C, c" K1 g/ o set current-light nobody ;; just for now, since there are no lights yet
6 B2 P! j/ e( ^5 W$ L: T# H set phase 0
5 s1 d9 \# T# w0 x set num-cars-stopped 0& q1 E2 w( |# ^) }
set grid-x-inc world-width / grid-size-x0 r# f/ x' A' P' Y6 q$ X7 W* E
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary( c! D3 z! b s' d/ }& v
set acceleration 0.099
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/ \, ^9 Z/ v1 {" y;; Make the patches have appropriate colors, set up the roads and intersections agentsets,4 M/ h I) A0 ^/ {8 J
;; and initialize the traffic lights to one setting; d% F5 r6 ?) E
to setup-patches
: g4 q, z! b/ q; B8 ~* V; S+ j b$ b& S! R ;; initialize the patch-owned variables and color the patches to a base-color
- l+ u$ n; q# n0 v7 a j2 K ask patches
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set intersection? false2 v4 G6 u; `7 x: m- r
set auto? false
, M( T$ }/ L9 n7 O' F9 Q5 p) h set green-light-up? true. O5 z2 g3 D5 a" M9 [0 Y2 _; _" h
set my-row -1
" [" g' K; b. E$ F" I set my-column -1
# e0 j2 a2 |# _0 z2 A0 U set my-phase -1
3 W) K Z; x" W: ~ C: C set pcolor brown + 3; v3 I& I C% t' l5 e* x
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* i: }7 w, E% L! t) \ ;; initialize the global variables that hold patch agentsets
5 D4 `% R. R' @, E$ V; e set roads patches with3 G" S$ |8 n7 T# V
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. N F( e+ n& d; O9 L5 z" u
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 p2 R" q' ?0 z1 O8 u3 T8 j
set intersections roads with$ Y: a0 s9 g& T! C$ X* J1 E
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
0 r% e. @5 a: A4 e7 d+ g \ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]- q7 \/ p3 i" P
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ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?
# T, n; ?6 V- s, ?; m set roads patches with1 z* [2 S _% L# B5 g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# i' O0 s3 ~/ F! j (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 s/ x4 `6 V# C; F9 d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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