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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。
" e) v( F* c0 W3 K' f0 I* r3 v! Fnetlogo自带的social science--traffic grid这一例子当中,
n2 u5 h/ L- N% Y/ N5 l. Oglobals
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0 T i( Z9 \ n, F& Z grid-x-inc ;; the amount of patches in between two roads in the x direction5 J* J6 {; N% C, Z. C, ^' `
grid-y-inc ;; the amount of patches in between two roads in the y direction: M/ K1 G9 F5 _
acceleration ;; the constant that controls how much a car speeds up or slows down by if
* a, F$ A- d% S* S" ~ ;; it is to accelerate or decelerate
% ?' w3 A) W; X2 ^0 ?' Z2 G2 E, n phase ;; keeps track of the phase: o/ y; I5 a; Y7 _$ o- N$ d
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
1 Q/ }/ r, m# e current-light ;; the currently selected light5 x( i) \% A$ S! V" k0 S: y+ `
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;; patch agentsets
& C6 b) Y+ ?% B5 R% e) L3 f intersections ;; agentset containing the patches that are intersections
2 b4 v, f, x! F k) c; C/ ]8 J roads ;; agentset containing the patches that are roads
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turtles-own0 p7 m) ^, O& \
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) \/ c% b) {6 h) \% p speed ;; the speed of the turtle
7 y+ B9 v+ Z6 e+ o up-car? ;; true if the turtle moves downwards and false if it moves to the right
! r/ |- p7 w8 `9 K wait-time ;; the amount of time since the last time a turtle has moved' w- w A" o9 D# M0 _
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) v5 @) a, a8 Ipatches-own
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intersection? ;; true if the patch is at the intersection of two roads) M5 F! }# J6 `$ X7 B
green-light-up? ;; true if the green light is above the intersection. otherwise, false.5 h+ v* c$ ~" E; W& Y( T1 y- b; w$ {
;; false for a non-intersection patches.
( M7 c5 R# L$ G# ^( b) v my-row ;; the row of the intersection counting from the upper left corner of the, D9 f" D/ d3 E: c% M' |0 u
;; world. -1 for non-intersection patches.
6 o$ a1 o1 o& d, v my-column ;; the column of the intersection counting from the upper left corner of the
1 F" i# [0 w9 e ;; world. -1 for non-intersection patches.
( J; S9 L) g+ D( n" q' k my-phase ;; the phase for the intersection. -1 for non-intersection patches.
6 x6 K3 O+ r+ \& k8 \' R" X+ ^' W' | auto? ;; whether or not this intersection will switch automatically.) O+ n c# M- w4 a X- _. M
;; false for non-intersection patches.5 U' I$ K0 W6 h/ ^
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) l5 F$ q- V8 L* R/ h) g, p;;;;;;;;;;;;;;;;;;;;;;
8 j( f8 C+ X7 V;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
: v6 D, k- \( \;; Create num-cars of turtles if there are enough road patches for one turtle to0 P K1 W: d7 B- n% ~
;; be created per road patch. Set up the plots.% Y1 g) |- s" V6 e
to setup
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) J* k$ W$ G9 x; O5 w, Q' B setup-globals
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: c' j2 U a' {& l ;; First we ask the patches to draw themselves and set up a few variables2 q$ l( Q. q. \9 i: l$ Z
setup-patches
& N8 b: k9 ?* _9 x9 O& T make-current one-of intersections
" k; r) O/ d4 ^ N3 | label-current
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; ^& M% g0 p+ Q* G set-default-shape turtles "car"
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if (num-cars > count roads)8 ?6 l- r! r. ~$ a1 P W, ]! x
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user-message (word "There are too many cars for the amount of "
d- [$ ?9 r p) V! B4 Y- N1 r$ ~, v "road. Either increase the amount of roads "" M1 O8 P5 b% v# x
"by increasing the GRID-SIZE-X or "
# a% z% h( s: J4 S$ q* Q "GRID-SIZE-Y sliders, or decrease the ". N3 v) | t4 D) l" }; f
"number of cars by lowering the NUMBER slider.\n", N# T. ?& r) s9 l
"The setup has stopped.")' z6 q) B, I; z3 C( ^
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
/ v& ? p4 } _% e crt num-cars$ A! l% Z/ L8 e8 X; L
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( ^: X( U5 Q0 z- q; m: j& s setup-cars
% {' h2 y2 }0 p. K" ?$ ^ set-car-color
) L+ P* e; x/ r$ }$ t record-data
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3 }. {; G w& r! j ;; give the turtles an initial speed, H$ O' j8 u, O# N4 m# I" s8 I
ask turtles [ set-car-speed ]+ D# X; {! m5 r4 e# w- h" T
% ?( X e7 I O h2 y v reset-ticks
5 y/ U6 c y& m. ?$ k# h0 B% Yend
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;; Initialize the global variables to appropriate values- R: m* v# u0 k. M* b9 `
to setup-globals) B. l. W; p* `; q1 k, W
set current-light nobody ;; just for now, since there are no lights yet `8 T: V1 t) m- r% I
set phase 0
# q* U7 T$ h% t% M set num-cars-stopped 0
& s" ^+ y' s% P$ e* K- T set grid-x-inc world-width / grid-size-x
+ z' d2 O7 L" c9 v) `& ?+ K! F set grid-y-inc world-height / grid-size-y
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8 k2 ]5 q$ |, G! z% k% Q2 ] ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
' q6 U# e2 a0 o( [1 ^* p- m9 E set acceleration 0.099
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! J+ W5 }; B" I }5 X/ B0 z;; Make the patches have appropriate colors, set up the roads and intersections agentsets,0 I: O ^2 W; s6 X6 K: S: X3 l* y
;; and initialize the traffic lights to one setting3 K, e2 M- r ]- H
to setup-patches
; d: Q( ?5 {: z7 f0 K: \' i ;; initialize the patch-owned variables and color the patches to a base-color
# g+ R3 e8 L/ ?3 S* e- | ask patches
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set intersection? false
0 `4 d8 S8 a+ C& s3 B! s6 N! F set auto? false4 w1 m. @- f' F8 r
set green-light-up? true
# @2 |2 v, ]& v$ c3 U7 y. t' g set my-row -12 M+ I5 e) A. \4 t1 q
set my-column -19 z) A5 \9 {2 X+ n5 U
set my-phase -1/ |, p0 {7 {. [! Z5 F+ i, R$ r
set pcolor brown + 34 Q% _+ F h) @% N2 A
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3 N- L2 P2 e( b* W- I1 D2 r6 W. z ;; initialize the global variables that hold patch agentsets0 L# N% h$ L2 z u8 S7 ~3 h
set roads patches with. C8 @$ f, y$ ^% l% v1 A
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
& |, Y! P+ k. {) J$ S) i; ^ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& O6 S) L5 P) C( ? set intersections roads with
$ T1 O* o f/ J! P/ m, z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
_+ b, J5 d) z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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end$ L& n$ B# M. Q. w
其中定义道路的句子,如下所示,是什么意思啊?
; w$ G7 d2 A E# k* F, ~" a2 K* N set roads patches with3 G7 T6 F. }) y! ^ Z( A3 b! G, U
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or }' U/ a1 K) K3 ^7 Z9 _
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 k c( W; H( E: R) 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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