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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" n7 { J( |netlogo自带的social science--traffic grid这一例子当中,
+ v! P9 U2 p2 A, c/ Kglobals% w" O2 O' ^: m L! T1 x* \5 }6 d
[
: G* T; |" c0 _$ E grid-x-inc ;; the amount of patches in between two roads in the x direction
' v7 W# _. R) j& v9 |2 i0 L grid-y-inc ;; the amount of patches in between two roads in the y direction1 F% J3 W1 @" j; w) U1 s4 {
acceleration ;; the constant that controls how much a car speeds up or slows down by if
) T$ X" Z$ d, e! [9 [: y8 [ ;; it is to accelerate or decelerate
% b5 {% h" V2 `5 s- B S phase ;; keeps track of the phase
6 z _: X: b0 W5 C, m- P8 C" z8 z/ F num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure# S3 E" o+ i0 P
current-light ;; the currently selected light
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;; patch agentsets/ s( @* U6 o2 w- F }! b; F& o
intersections ;; agentset containing the patches that are intersections) \6 n( P" e8 u
roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle* q+ Z A1 W- x+ Z
up-car? ;; true if the turtle moves downwards and false if it moves to the right
2 N+ Y# i/ M! s9 I wait-time ;; the amount of time since the last time a turtle has moved
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intersection? ;; true if the patch is at the intersection of two roads
) Z8 V9 {& S% H3 D1 a green-light-up? ;; true if the green light is above the intersection. otherwise, false.
' C0 k- R- q& Y3 F( D ;; false for a non-intersection patches.
; j" Q8 X% K) j( v+ f$ H% H% Z6 ` my-row ;; the row of the intersection counting from the upper left corner of the0 {" x. j' t( m$ `0 J) x
;; world. -1 for non-intersection patches.& l' f, m# k* L8 h6 g
my-column ;; the column of the intersection counting from the upper left corner of the
) B# F3 y; C* y% u% Y ;; world. -1 for non-intersection patches.1 p' ]( v6 x$ T/ X. X* R( W
my-phase ;; the phase for the intersection. -1 for non-intersection patches.9 r3 z* O" q" T, Z. G# M# U2 `6 e
auto? ;; whether or not this intersection will switch automatically. U2 b. O8 q) Q4 U l
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
2 `# M7 {0 A4 M! h+ @;; Setup Procedures ;;
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, T% A$ \; y; h9 n. @9 V( e2 g;; Initialize the display by giving the global and patch variables initial values.
9 J5 v/ p& s$ S' _;; Create num-cars of turtles if there are enough road patches for one turtle to G9 s) C! l; L$ j
;; be created per road patch. Set up the plots.
' Y. ~; p- I t: [3 I/ \* Ito setup/ Y# b4 R: L$ t3 g2 q) f; z# y
ca
- @( ]) m( [ ^0 ]% g setup-globals
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! A% l) v& _( q8 @" m ;; First we ask the patches to draw themselves and set up a few variables
& H! W0 W) m! v- G setup-patches
9 V* q# ^, d8 t. j7 B J7 [3 J make-current one-of intersections, y3 Z$ X) R; ]4 W$ h
label-current9 z* t: e" ^( W1 I
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set-default-shape turtles "car". p" `4 K, i# y/ x, K# P! J G
0 m5 y% u# c* U if (num-cars > count roads)* `. j3 z/ d* Z+ \1 Q
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user-message (word "There are too many cars for the amount of "
# E, E2 C) U5 d" ^4 V1 W. [& s "road. Either increase the amount of roads "
: u; m- R% i$ w/ [, M- R: H Z "by increasing the GRID-SIZE-X or "0 z# B" l c# C% U3 G1 C
"GRID-SIZE-Y sliders, or decrease the "; g4 T& @7 l1 Z7 r" R! d
"number of cars by lowering the NUMBER slider.\n"% m7 s" L+ `1 A: c/ r N
"The setup has stopped.")# F3 a G( [' t6 _/ p/ l
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
! W g5 f3 X5 {# O8 H$ O ^+ { crt num-cars; T y2 v! q. B+ v* E/ G y9 y3 [
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setup-cars
$ }9 S# `" P6 v t set-car-color
; g7 Q3 j& m* S3 `, w) n record-data( j: a, X6 ?/ I1 f- I% T
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* o( x, n, d' F& v ;; give the turtles an initial speed# |, E8 {; [% h) a
ask turtles [ set-car-speed ]
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reset-ticks
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/ |5 j9 L* ?$ T- H# E;; Initialize the global variables to appropriate values# [0 c+ S: w5 }, |. s
to setup-globals( g/ y0 k. G' W- i! P( n0 W
set current-light nobody ;; just for now, since there are no lights yet1 P( r" V: f _' a) Q! ~; @* Q
set phase 0+ M) K/ A0 \0 |& }$ X- J# A
set num-cars-stopped 02 G- O! h, @8 ^
set grid-x-inc world-width / grid-size-x
" g9 K6 ~6 q4 e/ g set grid-y-inc world-height / grid-size-y
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: |. i' u6 S7 m, ? ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
: c7 P% m' q' M* V! I0 j set acceleration 0.099 k; u; h4 @' n T g2 X
end
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) ~/ B, y* \9 v9 ^;; Make the patches have appropriate colors, set up the roads and intersections agentsets,3 U) {4 Z& p. `" c9 h5 ]
;; and initialize the traffic lights to one setting* G6 O* a! {, k8 t$ M
to setup-patches
' X1 i% E. q! R( O/ |( G( K! \ ;; initialize the patch-owned variables and color the patches to a base-color: W5 B8 c' D$ s: a5 ^
ask patches; I* j7 P/ k T f% [
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set intersection? false. ?8 ~; B% D4 j+ D' H0 `( Z
set auto? false. W, T+ a8 F8 Z4 T- p
set green-light-up? true
: I0 e. ]8 g# M+ I3 t$ g# X' q E. I+ H set my-row -1! M! y# n" f# s! o0 H. @' C
set my-column -1
( \& H) Z# f& p5 r set my-phase -13 R. q. n/ @9 e- Y, {2 o
set pcolor brown + 3
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. P+ c. [: s. k) p) b ;; initialize the global variables that hold patch agentsets' R: S+ \" T: G4 U; l- D9 e
set roads patches with0 h5 c& f7 T: D
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! J* t4 ]* J9 e/ c) ? (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 T1 Y8 v0 C& Y; B1 ~ set intersections roads with
3 [8 {, @% _" } X5 | [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 N7 m% q: F9 |! s! Y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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' C- ?( m/ W5 Q' w 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?' l. T3 V# O! U: o0 a% c
set roads patches with
5 }3 w$ c& i- Y M [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 D$ ^' Q4 X3 } (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) T% K& t8 F8 f- y; X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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