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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。
- p" }4 d5 `5 ]" x0 |" G5 ^, O7 Nnetlogo自带的social science--traffic grid这一例子当中,
7 u( @7 e. H, N$ \, x$ Rglobals
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|8 f, Q$ W0 x; _* t grid-x-inc ;; the amount of patches in between two roads in the x direction
/ H' `8 j( I0 C5 R2 ~4 H grid-y-inc ;; the amount of patches in between two roads in the y direction
$ V# K* k3 N/ i* T acceleration ;; the constant that controls how much a car speeds up or slows down by if
" M9 a, o/ ^7 Y, A: s) t+ s d ;; it is to accelerate or decelerate
G p/ d' H5 U9 K phase ;; keeps track of the phase* y& O( u/ u, |
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure9 @& O V8 b' R! m
current-light ;; the currently selected light
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;; patch agentsets
. e- c8 z& i9 ~+ `% }9 I" K0 x intersections ;; agentset containing the patches that are intersections$ G( ?. i1 o3 h- d+ G
roads ;; agentset containing the patches that are roads, F) U+ \+ U$ v( W ?1 k
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turtles-own
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: E$ Q4 |: E. f. y) w1 a" L6 m speed ;; the speed of the turtle% r5 S3 O3 t$ D1 H, x
up-car? ;; true if the turtle moves downwards and false if it moves to the right9 p# p1 z' b9 x# w
wait-time ;; the amount of time since the last time a turtle has moved- i. ]) j8 l' ]( l" |
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: m Z8 D) r L" Npatches-own& \9 g9 p3 t# z) W
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intersection? ;; true if the patch is at the intersection of two roads
6 w/ i% o7 O/ i0 ^ green-light-up? ;; true if the green light is above the intersection. otherwise, false.: m- }) l/ \9 g% T: H
;; false for a non-intersection patches.
+ X7 x$ x' m; e. w" J my-row ;; the row of the intersection counting from the upper left corner of the6 Z7 q, f* @" X: ]4 W' g" Y
;; world. -1 for non-intersection patches.
9 o. N4 p) [0 l' q; Q my-column ;; the column of the intersection counting from the upper left corner of the
1 c/ V) _6 C i! V5 K9 { ;; world. -1 for non-intersection patches.
- p) J& h% w5 s* x my-phase ;; the phase for the intersection. -1 for non-intersection patches.* G, ~6 o8 f' x2 f( W8 ^$ j) r
auto? ;; whether or not this intersection will switch automatically.6 Y; W! g4 n: l$ K
;; false for non-intersection patches.
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7 i- i* K+ L7 J9 l) D;;;;;;;;;;;;;;;;;;;;;;
: W. ^* M8 G v9 r- w4 `;; Setup Procedures ;; F' |" I# A& A: r7 O1 F
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
) M0 n8 _, f2 ^* t9 X4 O& s;; Create num-cars of turtles if there are enough road patches for one turtle to7 q+ Z) d: |9 n6 n2 z+ T0 M
;; be created per road patch. Set up the plots.
) W3 z9 D' |" Q T. N, ]% X! uto setup
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; X( i( p+ j# v, P setup-globals; t/ Y: @. Y+ r! ]% x% T
+ g0 e7 C! S; g; }8 _# S; T ;; First we ask the patches to draw themselves and set up a few variables
% G2 B) m- ], M0 Y3 P setup-patches
+ l) \: ^; F) i; h+ c$ e3 S* { make-current one-of intersections
1 e& J: @4 {8 n4 R) l6 m8 R. T label-current
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" X/ k8 J) I# F* O% c2 w) K+ C set-default-shape turtles "car", s# O$ L4 Z3 C F
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if (num-cars > count roads)/ s# E6 [4 B& {
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, D2 h. i2 x" v+ ~! r, j! w6 g1 d user-message (word "There are too many cars for the amount of "9 Y- L/ u+ L) L- q+ _& X5 Q1 ?
"road. Either increase the amount of roads "6 j( o6 l: j$ C h0 a
"by increasing the GRID-SIZE-X or "9 L" S& |' K# M( h" l: H# i3 m
"GRID-SIZE-Y sliders, or decrease the "
$ |0 o A7 i% [8 v "number of cars by lowering the NUMBER slider.\n"
$ ], l9 |, L1 e6 ?* I "The setup has stopped.")% h. h1 X) t N! ?; K
stop! i4 O+ K `$ n7 r( b& x6 U
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
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c- [! M0 Z+ N0 ~ I. h setup-cars
. K2 |* M# C+ d: ] set-car-color
& x/ U( K) i$ {6 i. B8 Q" C record-data5 R* P/ h U P9 ~4 L, h
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;; give the turtles an initial speed
% f2 T, s8 i* z: c: {& S l8 W ask turtles [ set-car-speed ]
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4 i2 T3 D. @ ~$ C" T reset-ticks
- ?6 @4 G& h# o; [6 Dend
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;; Initialize the global variables to appropriate values
; H) @8 g! V0 Z1 S. D. Eto setup-globals
N9 n1 a+ R1 t, U% P, O& M set current-light nobody ;; just for now, since there are no lights yet
* i" T9 ] g& i: ? set phase 0
: C5 o- g: {. |. k( G5 T( q4 ? D set num-cars-stopped 0' e: p$ \0 n$ w1 W& B; j! K
set grid-x-inc world-width / grid-size-x
: m/ `! a( H) n# r set grid-y-inc world-height / grid-size-y
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& W+ X8 @, N- H# f5 ?1 o ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
# R9 J5 ^# c0 ^$ O' u# ^4 u$ Q( ^1 I set acceleration 0.099
% T, ^* x% _1 u1 c" V2 u; }end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets, V6 A& d+ \. N- A7 i$ B4 n! X
;; and initialize the traffic lights to one setting
& T. l8 y4 _" F$ S) j' Dto setup-patches6 I2 o; f: f! H) j: Q
;; initialize the patch-owned variables and color the patches to a base-color2 o5 g1 D- m7 `% \
ask patches
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0 ^+ u/ z# D: p8 Y3 j# }& M: w set intersection? false- w3 Z. B0 R8 S) P% R; @* Y
set auto? false* J8 K$ K, U2 ~9 ]) _( z* w6 h
set green-light-up? true
7 E7 m. U9 G& C$ { set my-row -10 R {7 a# F: f e- H2 I
set my-column -1
* G3 ~8 G$ o* `* w set my-phase -1& {6 M8 A5 B! F+ h8 ^
set pcolor brown + 3- x, y* B9 e3 V2 _: m! \ ~
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W+ ^: g8 E% v ;; initialize the global variables that hold patch agentsets: K, v$ ?: \1 U. `
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ f/ H3 @1 ]6 L8 x g8 u
set intersections roads with/ ~# f6 |9 R4 w" I, Z/ p
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
+ [% i* l% X6 t% t) B (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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" U6 N3 \) z0 K) L ask roads [ set pcolor white ]
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end/ ? p; o( K. M2 w
其中定义道路的句子,如下所示,是什么意思啊?' Y9 i5 g6 ]) D1 k# d
set roads patches with
9 B4 a2 f7 u& t5 `& F; n [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' @. W3 f' ]& j' a (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 `* E3 g; J% r4 V0 ?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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