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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。9 Q- }7 Y$ v/ j" r. K" O1 d
netlogo自带的social science--traffic grid这一例子当中,9 b8 ` J: T. r5 y( e
globals* g8 a4 L+ F8 i& b& i7 l
[
' u) g$ m$ f2 W3 Y) }1 a grid-x-inc ;; the amount of patches in between two roads in the x direction( c/ F: ?- s( i) G y6 {
grid-y-inc ;; the amount of patches in between two roads in the y direction: b- n; R* Q) z6 A9 Z
acceleration ;; the constant that controls how much a car speeds up or slows down by if
/ k- T: ]+ y) w. A" ~$ ]; R ;; it is to accelerate or decelerate" B4 z* [/ D+ j" \$ ~
phase ;; keeps track of the phase
9 ^, N" b+ ^! s$ M" n) V* B n5 p num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure1 w! d- y& n, X$ ?3 O
current-light ;; the currently selected light
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2 s6 X/ j. S% J& r ;; patch agentsets+ E% g, A, j/ T% o
intersections ;; agentset containing the patches that are intersections4 ?2 I/ I3 ?! ^3 z2 q/ D# A' u
roads ;; agentset containing the patches that are roads8 e: Z6 F5 a, {! s2 J. z
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% t. a3 y/ a% ]2 i+ S# ?' iturtles-own
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speed ;; the speed of the turtle
* e' }8 `; k4 g# k) f) b( c) y up-car? ;; true if the turtle moves downwards and false if it moves to the right
) B6 _7 j! \( g: Z) T- p1 C wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads n, I5 ?' L4 ]' B/ m
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
" W4 u* R% }3 @: t, J$ ^+ [# A ;; false for a non-intersection patches.8 _8 F+ c: V' V' y ~9 {: k! E
my-row ;; the row of the intersection counting from the upper left corner of the0 I$ y! L# {2 j# F# @( V: p
;; world. -1 for non-intersection patches.
1 R% Q; U& j" k& c# t* q my-column ;; the column of the intersection counting from the upper left corner of the- N- z, x* d0 }4 J
;; world. -1 for non-intersection patches.
) X ?! @( Z x- @* a my-phase ;; the phase for the intersection. -1 for non-intersection patches.
# r' G- S. Y) V! l' G9 G$ U% d auto? ;; whether or not this intersection will switch automatically.) v, l* d6 m- g+ v/ y# s
;; false for non-intersection patches.- l, N) G4 A, x. H% ^& p
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& Q; d. y3 e1 A, \; V8 ^;;;;;;;;;;;;;;;;;;;;;;$ f5 r9 x+ `, V7 ~ N+ N" X" P
;; Setup Procedures ;;# F/ Q+ C7 }) x& ^! S, p
;;;;;;;;;;;;;;;;;;;;;;' a' }2 ^: r) b/ ]1 }! ^5 t
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;; Initialize the display by giving the global and patch variables initial values.3 D: n$ [% `7 q
;; Create num-cars of turtles if there are enough road patches for one turtle to
8 [6 F H1 u8 U+ c a8 q; S9 I" h. U( m;; be created per road patch. Set up the plots.
" E$ M, Z- t* P- u; Ato setup% N4 m9 ~+ H9 y2 X; R
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
( P7 M4 i9 p+ ]3 r7 h3 J setup-patches5 ~# P6 Q! b. O/ D% i. x8 }' K3 v' r4 l
make-current one-of intersections. X- n( }: K( r9 G
label-current
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- k+ p+ U2 n% @7 X" r set-default-shape turtles "car"5 S) `% d% n' t4 N
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if (num-cars > count roads)5 N6 K0 |3 A+ W. ]: }
[
! }- G( F. x) K+ e user-message (word "There are too many cars for the amount of "
2 C: f( e3 ^2 J+ Y "road. Either increase the amount of roads "
) U/ G; r4 y$ V "by increasing the GRID-SIZE-X or "
, B$ }, s( _+ d) f Y( T# c- D- Q "GRID-SIZE-Y sliders, or decrease the "
& ?; `( [0 b2 v/ r$ N. h "number of cars by lowering the NUMBER slider.\n"6 O$ [3 D: M& M
"The setup has stopped.")
% Z" J" X# U) F) W0 a# O+ W stop( `: [, H( m. P. b" F @: [/ W
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
( w% O7 J' M/ B6 a2 h9 h7 {/ |- j crt num-cars
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setup-cars
7 I2 U) l- z( Q set-car-color
+ Z4 \: U# I ~/ F" I r8 _ record-data
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1 M {8 f+ E! K0 ` ;; give the turtles an initial speed3 p* ~1 R0 Y# R# [- Y$ A5 O' `
ask turtles [ set-car-speed ]9 a5 g W. S+ g) W @1 ^2 g
: B1 t1 @) |' u8 e2 G reset-ticks1 A E0 O' I5 C
end' n7 r/ r1 K& x6 p
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;; Initialize the global variables to appropriate values
" N: n; L2 Z# A; bto setup-globals
' s. }7 T: K: ?" V set current-light nobody ;; just for now, since there are no lights yet
9 |" h/ a4 a$ I: P set phase 0
. Y; \9 e% T' Q2 S; t6 z7 @) ^0 ~ set num-cars-stopped 0
( P0 u' L) s, y5 O _1 g set grid-x-inc world-width / grid-size-x' D( T+ ~0 d6 Z
set grid-y-inc world-height / grid-size-y
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: Z; ~3 `$ Y2 S- N/ L6 @8 i8 G/ O ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary9 h8 X3 _7 R7 M3 d6 w9 v
set acceleration 0.0995 M/ K5 e v2 i# P/ r- R4 {
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
3 s& f! R$ G9 p6 Y* Y;; and initialize the traffic lights to one setting6 Z6 F2 |. B: ^1 I
to setup-patches
6 W/ {! a3 N# h/ J% d' a ;; initialize the patch-owned variables and color the patches to a base-color& V5 d1 D3 C# N9 J( u( j) C
ask patches
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set intersection? false
. t4 i2 l4 z; E' X- L set auto? false
1 \% L' V0 q4 P/ _; t. }; I( h set green-light-up? true5 a3 N: \: D3 G2 c. G
set my-row -1
k+ t0 {" `. T3 Q8 `+ f2 z* K set my-column -1+ \/ N' M w$ b
set my-phase -1/ F4 S4 c: J8 m1 c4 R/ g9 M
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets [. w( @! [$ r3 S3 o9 O
set roads patches with+ W8 S5 s" d7 t$ _. q3 W B
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* d: j; F5 t+ H3 T, e- T7 U
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% `5 [: W; }- D' y: g1 }8 J' X set intersections roads with3 d& C' _2 c2 a( B) ~0 C- x
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and l, ^5 P4 _' ]! e9 z! J
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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# r2 @' X+ s; ~. v" j" | ask roads [ set pcolor white ]6 \$ X$ @4 P& M* d! P% r
setup-intersections# N; y: j5 w( {4 \ x: w* c
end2 O# n" c3 G6 o6 m9 Q/ {& B$ J
其中定义道路的句子,如下所示,是什么意思啊?9 ~! t/ `# F4 T
set roads patches with
3 [0 ~, J; A6 f; b l4 t5 { [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' q) G5 ]5 x) g5 A
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]( }/ n# _5 n) A @& N5 g: a
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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