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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。1 `- M" G N. g; e
netlogo自带的social science--traffic grid这一例子当中,/ M: b2 q& a) F9 Y5 J
globals) n. A" O' R$ }
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# j0 Y: N1 ^" }# `, D" s grid-x-inc ;; the amount of patches in between two roads in the x direction5 @ p1 {5 E& Q( O2 O
grid-y-inc ;; the amount of patches in between two roads in the y direction
- [0 [1 Q! ?, P7 P& ` acceleration ;; the constant that controls how much a car speeds up or slows down by if
; ^1 [9 S1 h; @2 G% n& q$ H: ?( n+ G ;; it is to accelerate or decelerate& Q E$ } l2 W" F" g
phase ;; keeps track of the phase$ V! D/ `' [ @) Q
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure6 {: G; r+ Q) j
current-light ;; the currently selected light3 p1 e8 [) E9 [9 {! v
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;; patch agentsets# g9 Y$ D1 W5 y0 p" o( K/ w
intersections ;; agentset containing the patches that are intersections
; S0 ^9 I4 Z& U9 j3 k# r! w roads ;; agentset containing the patches that are roads
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turtles-own4 k1 d/ H1 z; v- A
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speed ;; the speed of the turtle4 @7 [& ?3 O' i6 }! M# l9 L) x7 }
up-car? ;; true if the turtle moves downwards and false if it moves to the right
3 m0 D! a" ]% o' y) |4 O x wait-time ;; the amount of time since the last time a turtle has moved
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r. {) X! K$ \: U1 z
" S2 E. \1 [0 m5 q: [patches-own: w* p4 E4 P- O1 H
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intersection? ;; true if the patch is at the intersection of two roads1 W O( W" @4 J5 j
green-light-up? ;; true if the green light is above the intersection. otherwise, false.5 P9 v- E1 N6 D/ [
;; false for a non-intersection patches.
" T) \# L7 C* g6 K my-row ;; the row of the intersection counting from the upper left corner of the
8 A; V# |1 [. S- ^. ]- n ;; world. -1 for non-intersection patches.* |$ a+ F# f& ]; o7 L% v( z
my-column ;; the column of the intersection counting from the upper left corner of the, }/ U+ B. Y- w4 D, P
;; world. -1 for non-intersection patches.
, L: @% J$ H; ?6 h my-phase ;; the phase for the intersection. -1 for non-intersection patches.
0 p% `6 a2 K z auto? ;; whether or not this intersection will switch automatically.
, \; t" p1 { I$ d ;; false for non-intersection patches.& W- M/ m& M$ o" X. K0 H
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- t5 J9 g! F$ q: r8 z# o. [# s;;;;;;;;;;;;;;;;;;;;;;
& W5 j2 J$ e" @3 y% f, h+ i- e$ z;; Setup Procedures ;;9 i6 i4 a' u- u
;;;;;;;;;;;;;;;;;;;;;;
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' b0 ~. j; f) y* @6 B8 f;; Initialize the display by giving the global and patch variables initial values.( }" u4 B. ?. \* j4 w* N
;; Create num-cars of turtles if there are enough road patches for one turtle to
8 c, q1 \# L& a- C;; be created per road patch. Set up the plots.1 S/ n& w' @( l2 Z1 A3 _
to setup
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_0 ~& |/ n3 B# @( R& I setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
" f) E& d; o5 H setup-patches
- q7 l( a; r- E make-current one-of intersections
- \& L6 h1 t; A' i3 b S+ w+ I2 z6 h label-current# E/ z7 {4 y! ~$ ~ _
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set-default-shape turtles "car"" |1 I5 N, M' n% f! N& p, m
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if (num-cars > count roads)8 P7 j+ d; A2 Z" \: r
[
Z8 U0 U! z3 k7 X$ G+ l user-message (word "There are too many cars for the amount of ") U3 [2 V( \9 ?0 B V* ^
"road. Either increase the amount of roads "
/ Y6 Y: s: [) P: I* |. U "by increasing the GRID-SIZE-X or "
: _$ z! y" k2 O$ `0 ^ "GRID-SIZE-Y sliders, or decrease the "$ K, b0 M3 {6 G. ?$ v7 q4 [, e
"number of cars by lowering the NUMBER slider.\n"- p) b* a+ j1 ~
"The setup has stopped.")) ^; F- X; Z7 y/ y
stop4 J8 E3 E+ t- n1 I) i B
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, \" u, [. i& p2 k ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
" l# o3 R& | t5 {6 }. f crt num-cars
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setup-cars
- H( `$ [. a) j* ~! R0 ] set-car-color
- c: X+ Q$ I8 I record-data3 X9 b) c* \, U6 n }: [
]
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;; give the turtles an initial speed2 {9 H9 j, K6 E9 @; f
ask turtles [ set-car-speed ]
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reset-ticks
5 V6 x$ x2 i% d' `4 r2 N! ]! L6 cend
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;; Initialize the global variables to appropriate values0 E8 A9 t3 l5 P- z3 V1 o
to setup-globals+ p1 [+ M9 I$ p Y
set current-light nobody ;; just for now, since there are no lights yet
, C2 v3 _& g9 R( n+ N* z5 t set phase 0
0 d$ I2 Y* ]. a: V: C3 G set num-cars-stopped 0
8 x+ s4 U7 b' s* Q2 v/ _1 ~ set grid-x-inc world-width / grid-size-x, E) S5 U8 O. \ o' Q1 }" Z
set grid-y-inc world-height / grid-size-y+ q+ h* G8 ~9 q( I5 Q+ X, H
+ X9 n: C4 E @8 L: D2 i" D ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary8 l t. r0 o, r; p$ K- m& \
set acceleration 0.099
9 f" g# X; ^& {- E- @end" R6 V7 `1 E6 T
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,0 O' q# N6 g( \' ]" S) D. C
;; and initialize the traffic lights to one setting* @# |) U Q3 j7 W8 s% i& {
to setup-patches
0 z5 Q6 [0 `+ P9 U ;; initialize the patch-owned variables and color the patches to a base-color j+ R/ e- r5 r+ Z/ A
ask patches* T; j6 s# n/ P- o+ w$ K0 F/ i4 l
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set intersection? false1 z9 k/ w$ Y7 c* ]9 ?3 d
set auto? false; \! D0 r4 `- L C# u3 i3 ?, T+ L
set green-light-up? true) p% Z5 _$ q" P& U5 s$ ^
set my-row -1
' h* h* ]: Z2 N7 \* r set my-column -15 j+ P0 t7 Y" \- e* q
set my-phase -1
$ x/ J% ?# @7 U3 S' l- { set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets' ^5 S0 I5 \8 M# s/ k) D
set roads patches with
) H8 P# u6 Y1 P- s [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 P# E2 F: j2 j( h3 H5 x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ q$ @; j& ^ `7 i* d
set intersections roads with7 l1 b2 F8 R2 E# t& q2 X. r0 B0 L0 Z- H; Z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
J# ^: ~ r+ ]% V T3 B& h1 ^. B (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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& o; x1 t# ]4 N- V- ^+ W5 S' ? ask roads [ set pcolor white ]
5 V( H: W+ t+ }$ p: @ setup-intersections5 Y& R2 J$ ?+ f5 _" w$ a0 d, ?& q( L
end0 Z* Q. ?4 l" d
其中定义道路的句子,如下所示,是什么意思啊?
! c6 H2 q6 P( Y! d$ M) } set roads patches with
/ \% Y% J" J& S- K- K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
4 p) {. z5 ?/ t6 p I( y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ O! G T9 q8 `# T" f
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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