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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。% N- v: Z {1 c; {) D- ]
netlogo自带的social science--traffic grid这一例子当中,
/ q% M# W1 {+ [/ ~ E- }2 bglobals* u3 A& P$ ^1 w3 N
[
, C; s/ X) e2 g, R8 E1 O. H( p/ q grid-x-inc ;; the amount of patches in between two roads in the x direction
( P5 S0 z8 I2 v2 s c grid-y-inc ;; the amount of patches in between two roads in the y direction* L$ Q/ F V# s. F' S) `6 ?, j k
acceleration ;; the constant that controls how much a car speeds up or slows down by if
3 r- k! ^+ k; \! f% w; c: ? ;; it is to accelerate or decelerate# z" e* c, B; e5 r
phase ;; keeps track of the phase
6 `# w7 f9 V) `. w6 U; |( P% q- i num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
+ Q, ?) t( [/ n current-light ;; the currently selected light5 y; C. F4 i" d6 O1 }$ n
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;; patch agentsets
9 h2 |$ N9 x) `& k intersections ;; agentset containing the patches that are intersections
# x! |* X# S( {% T; R, c3 }. Z! O- s roads ;; agentset containing the patches that are roads
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turtles-own* v9 Z2 { a4 \: f' I% B
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speed ;; the speed of the turtle
% P, \6 H) s' c1 o up-car? ;; true if the turtle moves downwards and false if it moves to the right
2 ?$ J( ]0 h0 e. V6 K% d% z0 b wait-time ;; the amount of time since the last time a turtle has moved; G8 F* s' e1 p& {8 h, d
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patches-own2 B5 p& B7 ]5 I6 c
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intersection? ;; true if the patch is at the intersection of two roads
3 ^3 ]# @1 r- D6 L green-light-up? ;; true if the green light is above the intersection. otherwise, false.5 ~% m$ a T7 f$ O
;; false for a non-intersection patches.
1 M- t1 H% v0 m$ D6 K5 d. X: T* e) [5 v my-row ;; the row of the intersection counting from the upper left corner of the* f0 | f) b; N* k9 i
;; world. -1 for non-intersection patches./ \) e3 p# _, ?& G6 o
my-column ;; the column of the intersection counting from the upper left corner of the \, Y- u) H# O; @% F( v% V
;; world. -1 for non-intersection patches.
/ z% _$ n, U, r7 U: X. E8 a7 Q my-phase ;; the phase for the intersection. -1 for non-intersection patches.
! x4 j8 v2 }' N* G) A! T auto? ;; whether or not this intersection will switch automatically.4 N6 O h$ A. c$ r" w
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
) f# v( s. o0 G;; Setup Procedures ;;4 `1 p2 ^8 E8 o: F; `& `" |4 o& i
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3 Y7 u4 o5 u% y$ R# L" _;; Initialize the display by giving the global and patch variables initial values.4 n0 e2 B. U' B6 g! v
;; Create num-cars of turtles if there are enough road patches for one turtle to. C9 W: M$ `$ ~4 ~( m
;; be created per road patch. Set up the plots.
8 Q* u$ K8 C) ]" j- j, ~7 J( d' l& hto setup
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! \6 w1 E" Q! R setup-globals0 Q- z \) v% r1 \
; ]/ [9 u" K: P ;; First we ask the patches to draw themselves and set up a few variables% N! ]$ b8 P$ [" X' g. t/ J. O
setup-patches
: Y/ d# c" k9 ^+ Z- b make-current one-of intersections
p' S, ]8 B. @3 X2 C7 C- r label-current$ L7 p- [7 M8 i1 m; T. X
. Q& _% g; m, I, I) J( O set-default-shape turtles "car"
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M. F0 @; G3 s& v) u4 e4 @0 d if (num-cars > count roads)
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$ q3 Y% T$ V" \" p5 z- E4 P user-message (word "There are too many cars for the amount of "3 L4 S1 f7 Q& m7 U2 V% p! e
"road. Either increase the amount of roads "
: C; b: O- |8 Z "by increasing the GRID-SIZE-X or "
& }3 r/ X# H& \" C" Y& P% p9 M "GRID-SIZE-Y sliders, or decrease the "9 j2 q1 A/ i3 ~8 ?7 t
"number of cars by lowering the NUMBER slider.\n"2 Q/ L4 n" b) e0 t% S3 ~9 `& o2 ?
"The setup has stopped.")) X. s: P; A) ^% i% T' L* c# R
stop0 t! ^! _- P" p% \% i6 J8 o# @
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
/ `0 A4 f2 T! i' a7 i1 Y' H crt num-cars
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$ A/ r+ B2 M" B0 V& | setup-cars& H/ Y% ~6 b! T# e! B: _9 S
set-car-color
9 S& r/ l' H/ k. I record-data
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;; give the turtles an initial speed/ H- p: M3 q R% o
ask turtles [ set-car-speed ]( B$ ?5 I3 ^. D4 K. F/ S
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reset-ticks+ f5 F$ i* J' p* W4 W3 `
end
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8 y4 a* F4 S7 |! @5 A0 ?;; Initialize the global variables to appropriate values. m5 K& F0 W. A8 L* k5 u3 U
to setup-globals
6 \# x! H+ h, Y- o) l1 o set current-light nobody ;; just for now, since there are no lights yet
. m; v) Y$ R& U set phase 0. F9 U5 |* H* M# Z$ o5 f' N& m; u
set num-cars-stopped 00 ?9 P0 m9 m7 H2 E6 v. j
set grid-x-inc world-width / grid-size-x
5 h0 }9 {9 x7 X8 c) y8 L set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary4 f" }6 L" n/ B9 N/ h- K' f
set acceleration 0.099' x( l! z; D$ E, J; {
end
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/ J6 X: @( F8 b* b' g* [& k! K;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
/ d- c, B& S7 _- P0 m5 t;; and initialize the traffic lights to one setting
3 p5 n$ i5 d9 n8 J8 Ato setup-patches4 f" J6 @$ r8 K4 D
;; initialize the patch-owned variables and color the patches to a base-color
) w _4 L8 j# j4 D( } ask patches8 X) W9 S1 s$ F; a
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set intersection? false( d3 ^/ o. O: W+ c
set auto? false
! p2 l; Q% ^6 t# c+ \: e. K set green-light-up? true$ r! z1 x/ g- {' j& h2 c
set my-row -12 r9 x1 C& b4 G5 l
set my-column -1
3 C0 w$ I. R% @1 K2 Q set my-phase -15 p" w! c+ R( x: O4 |; m- X
set pcolor brown + 3
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|3 L( z# N% C- M( m9 u ;; initialize the global variables that hold patch agentsets; }) q8 u. ]. f: ^2 f
set roads patches with
& U, q+ a' f5 g [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or8 K6 f& y4 b7 B- x
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 Q. J+ ^% U# T3 G
set intersections roads with
& w. v# h8 y2 S) O [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
! K; b- Y' g& \8 J9 o5 A6 M (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ] M& i* f& u9 |* b9 C
setup-intersections
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) D/ C$ x2 [4 Z1 `其中定义道路的句子,如下所示,是什么意思啊?
% w* Q1 ]) I$ s1 |1 v* _% H/ V, o) a set roads patches with4 V8 I) u, w" L8 {6 b8 t
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or/ J1 k: ~, V$ T) h; d: U
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 z; `1 i; x- o! s9 H% j5 @9 d: k2 u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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