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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。/ t% C6 u* b3 r4 f
netlogo自带的social science--traffic grid这一例子当中,1 V" p0 S' l# W# Z8 M' W6 y
globals
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8 `% D# j* J3 k4 W) Y6 g$ E grid-x-inc ;; the amount of patches in between two roads in the x direction
* B8 i: g% q. v7 X6 m2 v/ V grid-y-inc ;; the amount of patches in between two roads in the y direction5 S0 g$ _7 s4 t& c; W* M4 g' s
acceleration ;; the constant that controls how much a car speeds up or slows down by if
- T8 c j( ^2 \0 i3 L$ T3 H ;; it is to accelerate or decelerate
! y$ Y: E% H# m/ J/ Z$ \9 B phase ;; keeps track of the phase
2 X; J" c% r9 ?& v! d num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure* Z& ~: |; q, Z% }+ c% a1 F
current-light ;; the currently selected light$ D; ~9 U+ T1 ^/ |# i9 }$ X
0 x+ h6 `/ y! J ;; patch agentsets% G% a- m/ ]5 z# w3 S: O3 a
intersections ;; agentset containing the patches that are intersections+ }, h0 y y7 i& |. Y5 n( Q
roads ;; agentset containing the patches that are roads
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; V6 T1 _2 c* w2 X! [turtles-own
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speed ;; the speed of the turtle
0 x# q0 ~" B' N W, B9 E up-car? ;; true if the turtle moves downwards and false if it moves to the right& Y8 @$ D8 g' u7 x
wait-time ;; the amount of time since the last time a turtle has moved. a- K% h- u$ x
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5 [& M, ~' I% }4 ~0 Tpatches-own* ~( A. f2 S: U, Z H5 c
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0 ~2 A* Q; P6 I$ h& e intersection? ;; true if the patch is at the intersection of two roads. L5 |* P# F" A- ~, W
green-light-up? ;; true if the green light is above the intersection. otherwise, false.( q" F" K1 ^: v3 h
;; false for a non-intersection patches.8 E: g7 X, r) t( }6 ^2 u; c5 v
my-row ;; the row of the intersection counting from the upper left corner of the' \8 A- B; t6 Z% {
;; world. -1 for non-intersection patches.! e7 G% @! I; E* z5 a. j0 b: h) e
my-column ;; the column of the intersection counting from the upper left corner of the1 W5 x s7 {( R6 n$ a
;; world. -1 for non-intersection patches.
' }. c9 x0 b; m) u my-phase ;; the phase for the intersection. -1 for non-intersection patches.( C5 L: Y3 D( @9 I- [9 y
auto? ;; whether or not this intersection will switch automatically.
; j' t6 m6 W6 E, h. E: j ;; false for non-intersection patches.0 M U3 u1 _" n9 Q; r m
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$ X8 O) |7 X* c- S7 };;;;;;;;;;;;;;;;;;;;;;, }9 E/ ~3 z6 }% u
;; Setup Procedures ;;- M! r) j, h4 s& L* P
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: @# g: }/ G& G- }4 R;; Initialize the display by giving the global and patch variables initial values.
: s1 H7 L" ~( J4 G% C( w;; Create num-cars of turtles if there are enough road patches for one turtle to& g# @: A! E/ ?2 k% W- I- ?
;; be created per road patch. Set up the plots./ ~% J0 b2 W) y. _$ s% A
to setup$ _ d1 d( [% {9 R
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setup-globals0 ?) H9 l6 D {% s9 I
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;; First we ask the patches to draw themselves and set up a few variables9 `$ f. A) G+ @& Q+ w
setup-patches
& x/ E/ h( P2 K% Z! _, n) \ make-current one-of intersections
1 B6 [ e8 b3 l# E& Z label-current7 U( W/ `5 N) \( U
6 L$ q1 h9 k; p e+ g set-default-shape turtles "car"
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* J& f7 \% @( r if (num-cars > count roads)
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% G: N9 S8 D- r0 x% O' I user-message (word "There are too many cars for the amount of "
9 |, F: t- c) d1 V "road. Either increase the amount of roads "
6 B- E3 z9 l: c4 i "by increasing the GRID-SIZE-X or "
# [, ~" v$ Y# r, L- s "GRID-SIZE-Y sliders, or decrease the "' B8 A6 Z, r% g$ _& ]0 A+ G
"number of cars by lowering the NUMBER slider.\n"
2 p5 S: {" ^6 F i' R3 a# \ "The setup has stopped.")& k# U" ` C& R' U9 r& K, k' L* b
stop
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* `" ] k7 ?; x- a ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color u J) z$ Q* T& ^# \: @2 ~
crt num-cars. G, m% L* _; y
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setup-cars
! U% Y& N6 C4 A set-car-color
* b+ v$ Z% {9 C# C/ S record-data
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;; give the turtles an initial speed
! w/ u9 B( }, X, D ask turtles [ set-car-speed ]; ^; [# T9 n' ]& v( J$ y
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reset-ticks a) t# l" K, v1 |, t
end" x. @1 V B ~! V. \, @
; X+ l( g. Y% F" M K3 C; L6 k! D;; Initialize the global variables to appropriate values+ s: G$ w% Q" x- Q/ b- g( h$ |+ [! q
to setup-globals
2 j0 j4 j1 N- q set current-light nobody ;; just for now, since there are no lights yet5 s. l9 Q3 q; L% s& b
set phase 08 t- f T5 W8 h" B) b' o
set num-cars-stopped 0
) E4 T: C a9 I/ N/ ?; k% ~* x' w set grid-x-inc world-width / grid-size-x
9 S/ A4 q% E; l set grid-y-inc world-height / grid-size-y
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7 o. i8 K( V/ K, O2 {6 v l9 m ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
. W3 u J, _9 J% B, |/ r- j set acceleration 0.0993 @) Y. ~6 g2 X2 L* @
end
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" S( H: c; R) n- f;; Make the patches have appropriate colors, set up the roads and intersections agentsets,3 {+ r9 ?, S+ K
;; and initialize the traffic lights to one setting4 V3 R" s6 h- B+ v2 e
to setup-patches
6 B2 e! T1 D, L! ^+ X ;; initialize the patch-owned variables and color the patches to a base-color
; S" V- H3 z+ k: { ask patches
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2 q, @1 L7 S% U1 J! M set intersection? false
}) e; l- Z9 D6 w$ ]8 T6 X set auto? false
3 G: _: o3 p8 O" N9 S) {1 e+ { set green-light-up? true- K3 ]9 R5 u& X( S
set my-row -1
; x$ j! L1 V1 C, Y set my-column -1
) v ~6 \' B: U5 r+ v6 e set my-phase -1% N! e, f' l* s1 e
set pcolor brown + 3. K5 x( { z! |2 g0 f
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9 ]% `2 ~) J; W! ?/ {, [ ;; initialize the global variables that hold patch agentsets: b5 J r' ]4 l1 `: e
set roads patches with) G W/ C" m9 c8 l2 S) H- E
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 P- z3 _. E m7 N0 R& e. ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 b8 e/ M5 I/ V. k# t% `: J- |( T
set intersections roads with
' H2 ]" H" @# w+ v( p [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and+ c! V; k% T( }- ?1 ^
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]; i/ E0 J M+ x! {9 q' h
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ask roads [ set pcolor white ]8 _5 a/ j6 m" g
setup-intersections0 c6 i @0 X9 |1 z1 a# ^8 ]$ m5 e
end
# N2 i5 c8 B, A! g1 h* V其中定义道路的句子,如下所示,是什么意思啊?
( O% f; {, i$ _0 Y/ X( A/ k: w set roads patches with
( j5 Q' l( L0 Z$ H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 d4 P. |. [* I (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 Z. A8 `' t3 l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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