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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。
z! R F! V9 r& Q, f1 W1 m Anetlogo自带的social science--traffic grid这一例子当中,
; v5 `, i6 k8 tglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
) X* C5 ~' Z7 ^0 q& s x grid-y-inc ;; the amount of patches in between two roads in the y direction
" |( b( @& |% [# b i acceleration ;; the constant that controls how much a car speeds up or slows down by if+ c' b% \0 i' I5 e
;; it is to accelerate or decelerate4 z* R% h6 `; ^* k' l! q
phase ;; keeps track of the phase# j! s" {0 y4 I- w' U
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure4 \6 ]) P/ Y4 p0 k( b6 m. ?" A
current-light ;; the currently selected light
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& U8 [: i, e# d1 [' r( M/ h ;; patch agentsets: H! K2 K( u5 R0 J8 U
intersections ;; agentset containing the patches that are intersections
. b' d7 x# u4 C5 |( ~ roads ;; agentset containing the patches that are roads+ X; W0 g' J5 H3 H" T5 w# `5 b
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turtles-own; R' ]# w9 ?% C0 Y$ Q: @! f
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% f: q" G1 x4 _8 \" m speed ;; the speed of the turtle( o) X M3 }% L+ B$ r. d
up-car? ;; true if the turtle moves downwards and false if it moves to the right
& m2 c# o: u2 Q) w3 J) I wait-time ;; the amount of time since the last time a turtle has moved4 Z6 @5 \" T. y0 L+ E' ~0 ~* N
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patches-own7 E2 H, n2 x2 T. j1 X/ }
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8 P$ R! D, V d5 L) }) ~# h9 y intersection? ;; true if the patch is at the intersection of two roads% c0 T2 u8 ^1 Y7 j' [; E* Y5 K0 m
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
0 \, Q- d& j: w N/ ] o( A ;; false for a non-intersection patches.
7 K" z2 X7 M) l2 H my-row ;; the row of the intersection counting from the upper left corner of the: x9 z1 l* W/ s* Q, o
;; world. -1 for non-intersection patches.
. j( @% D' [: J my-column ;; the column of the intersection counting from the upper left corner of the
' E5 R, r- N2 q" `3 {! R3 l7 r ;; world. -1 for non-intersection patches.
8 K" X$ a% [0 y my-phase ;; the phase for the intersection. -1 for non-intersection patches.: l r/ M+ x6 V" _1 n- P
auto? ;; whether or not this intersection will switch automatically.& K6 z* I+ v+ r; X2 _; x" r
;; false for non-intersection patches.5 |$ |% _# y4 E; r9 c" |
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: U, m( w$ d, i6 g$ h;;;;;;;;;;;;;;;;;;;;;;
9 a. D7 ?) x: F/ K;; Setup Procedures ;;
8 E6 ]1 j, N9 U! n;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
" v4 c8 d1 N$ J- A8 R [: l, X) a;; Create num-cars of turtles if there are enough road patches for one turtle to
. A# R- D0 V% }! O; h5 j9 m;; be created per road patch. Set up the plots.
4 H! ~: f0 `& q( `2 I- tto setup
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setup-globals
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# m2 S6 K; T" [9 X ;; First we ask the patches to draw themselves and set up a few variables1 B3 @, Q6 p! K$ J$ V
setup-patches
2 Z& o# Q( r& d) p9 R7 @ make-current one-of intersections6 v: s+ S# |/ ^7 H
label-current
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set-default-shape turtles "car"
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$ P1 P; Q0 y! c6 U if (num-cars > count roads)) p5 _9 z/ u0 I
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- P) u- u- x s9 u& i# T user-message (word "There are too many cars for the amount of "
' P9 G. b8 u& m ?" w "road. Either increase the amount of roads "
% S5 l& ^1 ]0 u) O0 B3 g G "by increasing the GRID-SIZE-X or "
: Z0 X) J' ~$ g2 W "GRID-SIZE-Y sliders, or decrease the "
3 Y0 I! ~8 O6 ?9 m* s+ P4 R "number of cars by lowering the NUMBER slider.\n"& T) d0 V) d; d# E' v, `! Q2 L9 T
"The setup has stopped.") l1 k+ j- X9 N! K$ [. Q0 m9 W
stop" P* |9 x: q4 y f% v7 L" n
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) j$ F3 ]7 f& y7 K% b9 X# a' E$ D1 M ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color- H/ P1 H# _) R* a9 v; f7 F
crt num-cars
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setup-cars
; t6 k p: |0 A: W set-car-color. e+ s0 q! S9 t& g0 {
record-data
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;; give the turtles an initial speed( V. u# p8 @/ d
ask turtles [ set-car-speed ]
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" s9 N8 X: y# L; `% S* g' t reset-ticks: k3 h7 C {, S$ v! |% \8 ?
end( j% U! R% J# U& M* w; F1 e8 b
* f' F; E: I! O; {* L! S" G6 G;; Initialize the global variables to appropriate values
: U8 B% Z s, g8 ]* y. \7 L- _" a3 [to setup-globals
. v7 N: q4 E, ^3 b- |% V+ @ set current-light nobody ;; just for now, since there are no lights yet
! k: I9 {2 }8 h2 Y- X# T% j' _+ | set phase 0
6 e" I, l9 V. Y. |- Q set num-cars-stopped 0
& s- W: @' z* c8 T& p3 B3 ~. s; P6 e set grid-x-inc world-width / grid-size-x) D, E* |, }- `3 |8 R
set grid-y-inc world-height / grid-size-y' V9 T: U+ T3 d2 D: ]6 V
4 h# j7 [1 u% ^- R ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary, h: C9 j5 D; G. }- u9 V
set acceleration 0.099* L O1 S# i+ d* E& @' k3 @1 M
end
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: `" {+ l/ {( m;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
" ^! [3 C7 b2 ?: |8 ~9 p- y1 G" g& c;; and initialize the traffic lights to one setting
, Z/ ~! J8 i9 F/ V4 ]* C) _' q% P0 Jto setup-patches* `& S ~+ L k/ H3 p8 ?8 A
;; initialize the patch-owned variables and color the patches to a base-color
- _: T: K+ M; s; p( V ask patches, K/ H! `9 r: g
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set intersection? false
3 r9 d2 T- Y5 ^7 S) u9 Z set auto? false4 Q0 n3 f% ]+ H' I. I/ h
set green-light-up? true. `* J2 g' F* D( V, B. z( |: y
set my-row -16 b' \, _: \' {' N6 C
set my-column -12 i& v; f0 p! @3 a: K4 ]1 B
set my-phase -1
# X1 Q" @! _3 a9 f" { s$ G, W }5 s set pcolor brown + 3/ h5 M3 D. ]5 k# G0 G7 l' {
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. o- d# i/ `2 X2 ] ;; initialize the global variables that hold patch agentsets$ U: s$ K7 ~, v/ x& e1 _* c) y. Y- ?2 b
set roads patches with
( i/ U8 R) y9 {. ^ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( s( A. T# f; _; W$ L# k1 z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 Z6 u) z5 q! E6 m
set intersections roads with( M# W6 w3 \5 l9 P
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and+ {" J" U7 K$ B/ R$ ^# r
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]* M& T2 C! Q$ l1 r, s7 Z: B2 d
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ask roads [ set pcolor white ]+ g, m+ n- s. E0 `- ^
setup-intersections2 d- [; n- F& `2 R2 R( v# } P/ a7 \
end
5 T. j" v5 z: n/ K6 D其中定义道路的句子,如下所示,是什么意思啊?& I) Z# ^ O4 O- [
set roads patches with
2 l6 d" x/ N/ |1 D5 A [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# L( m4 ^1 f+ Y, p( V# } (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' c7 m7 G( u1 J: o% w) g" \
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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