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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。0 ~3 I1 t! W5 D. B+ q: ^: m
netlogo自带的social science--traffic grid这一例子当中,7 @7 _3 A; {1 [
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
* _" u7 e. m8 u- w" D0 E grid-y-inc ;; the amount of patches in between two roads in the y direction, B0 {0 E) k6 i
acceleration ;; the constant that controls how much a car speeds up or slows down by if
z. g# s& ^1 n j4 z: z( c ;; it is to accelerate or decelerate: `* d9 F9 G) N: E+ m9 q
phase ;; keeps track of the phase
8 d$ G; ~5 ~$ _. i num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure5 A. f0 o( u3 B0 A5 l. e. L( s. D
current-light ;; the currently selected light
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3 k: h2 s# B, j& e ;; patch agentsets
: U. ]+ {2 z, B# m( w& D9 L intersections ;; agentset containing the patches that are intersections
$ O4 r$ t9 t) G! @3 v- s1 t5 s roads ;; agentset containing the patches that are roads
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turtles-own( s/ @% w/ @. c! X; b% L* \
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speed ;; the speed of the turtle
2 T- L T% `% j* X9 j# n up-car? ;; true if the turtle moves downwards and false if it moves to the right0 Y1 L% `/ h. ~# q; `! X5 a0 l( h3 X
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own" I7 F4 L/ c: y- j4 v
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; t! ~3 R: U# U; P intersection? ;; true if the patch is at the intersection of two roads
& |1 _3 J1 F; D& _. _9 x# X5 E1 |4 K green-light-up? ;; true if the green light is above the intersection. otherwise, false.; R( j" ]1 u5 C7 ?
;; false for a non-intersection patches.
; ?9 n2 C: Y+ m; D$ X: C' h. b9 T$ R my-row ;; the row of the intersection counting from the upper left corner of the
0 @# C: B* w3 ~7 u3 `+ t) ~8 j ;; world. -1 for non-intersection patches.
- R6 O. K% }# c; ~, X my-column ;; the column of the intersection counting from the upper left corner of the1 N. q$ ~/ i( S. _/ k" d
;; world. -1 for non-intersection patches.
6 D( a( d# n) C |4 d my-phase ;; the phase for the intersection. -1 for non-intersection patches.
* i0 s+ y* L6 q; y: Q0 h1 N& ] auto? ;; whether or not this intersection will switch automatically.
" _1 E( O5 @- y) x: K) o, { ;; false for non-intersection patches.
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- O/ W) A8 U# {5 H& k;;;;;;;;;;;;;;;;;;;;;;+ v2 W! H- n# c) |) K
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.& a9 O! z2 q7 @0 I* U. N
;; Create num-cars of turtles if there are enough road patches for one turtle to2 m1 c- x0 {) }$ ]
;; be created per road patch. Set up the plots.: i% V F" x2 g& Y/ l, F
to setup+ T, Z r! H$ ?% R
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setup-globals, e& J/ F, f z: M$ H9 t
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;; First we ask the patches to draw themselves and set up a few variables
& j! g2 {, G3 d$ p+ F setup-patches
! ~4 S7 x5 ?2 J* G$ y% B1 M make-current one-of intersections" a6 s. @( g: J: \* ^5 {
label-current) X, O5 ?( K& A* F
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set-default-shape turtles "car"
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. g. E% R* o& n! K- ] if (num-cars > count roads)& |3 T8 M* H/ l3 }- p- E" U
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3 ^- O0 y m x4 c, d2 s- q7 G user-message (word "There are too many cars for the amount of "
& U. I s' a. \ "road. Either increase the amount of roads ". H5 L; }0 U9 o) N9 }2 T
"by increasing the GRID-SIZE-X or ") o- F& I7 u, W2 k
"GRID-SIZE-Y sliders, or decrease the "* ]7 D+ m8 s: {4 c1 r
"number of cars by lowering the NUMBER slider.\n"
& [7 S: W3 M* h "The setup has stopped.")$ i( P1 X. c$ x: P* ~ k
stop* P( F/ p1 r; N. Z4 o5 k
]
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
1 V; v2 E5 O7 I crt num-cars
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setup-cars
' a! j0 b) a1 L; s set-car-color: U% q6 X0 U0 f2 L" v4 v- h1 s- ~
record-data9 U5 j( w" T7 G
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;; give the turtles an initial speed
) i$ e3 ^" b; R' G9 p ask turtles [ set-car-speed ]
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* J8 C$ l9 s) ] reset-ticks
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5 B3 e, u; G- H W6 d- @: D$ Q;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet: K7 i) ?) g, [5 ~7 S& q
set phase 0
p# ~7 E' N/ w4 m set num-cars-stopped 06 Q% X, {( y, K' c
set grid-x-inc world-width / grid-size-x" W. E+ d% l5 Z) G5 @0 s
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 boundary
5 G/ t5 L z! M5 Z set acceleration 0.099( ?' i; N# K5 W) H
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
9 x% Z$ b3 G1 O) l R;; and initialize the traffic lights to one setting5 _/ R1 a i2 u7 W1 A$ r# @
to setup-patches2 n: r( g/ u4 `& z
;; initialize the patch-owned variables and color the patches to a base-color
; u; R3 r; h0 |# r# W* \' m ask patches
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: ^# ?. A r( b+ Q5 J set intersection? false
b, {: _4 @! M& f( m5 t! u* ]# t1 d set auto? false
( y& p+ a) C, d5 C Q! { set green-light-up? true
1 k* ^: w* @" J: b, P T set my-row -1
) k7 K: |( [3 g) z1 o& F1 R set my-column -1
" ?$ {0 h' c& p9 P$ y1 q set my-phase -1! L9 Q% T- }6 \$ i+ g$ M- |, _
set pcolor brown + 3
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! }6 U' S1 \, p. b# b8 F. W ;; initialize the global variables that hold patch agentsets
4 Q$ i% K* b- c5 R; i7 D) `$ ?5 G set roads patches with
( F3 d, G6 O& Y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 {# D( M$ l! K) Y0 z8 p (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% C& G; Y5 s/ g9 |3 ?) l set intersections roads with
& v& p& n0 j: O& O6 J [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
) S5 n x j" U! Q8 ?- h. z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' l; {1 x8 _$ U: D
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ask roads [ set pcolor white ]
% h5 A# U0 C; E) U; T setup-intersections
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& h$ Z# t1 s- K- J5 {8 q6 k: N其中定义道路的句子,如下所示,是什么意思啊?
1 K( j0 K) k2 r3 }# z! z set roads patches with0 a% O+ C* T7 u" e: I0 n# c: Q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- [" \8 T, G$ f# m; p (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, X2 H$ H ?6 ? i, i/ ^3 @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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