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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。 @( |: }* E1 t7 A
netlogo自带的social science--traffic grid这一例子当中," s+ E, U0 b8 T, U% q+ j: B
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction" j/ R# w5 U8 q) d. I5 V
grid-y-inc ;; the amount of patches in between two roads in the y direction+ [5 q) k5 K# }, h3 b- M* p- D2 W2 \
acceleration ;; the constant that controls how much a car speeds up or slows down by if6 K* ]( k3 Q* O( q
;; it is to accelerate or decelerate% u* T7 q% \3 J1 W7 {! }, V
phase ;; keeps track of the phase- y; e. K# x! {' j p
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure& t$ u- B2 P/ U& S, n) O% Q" q0 U
current-light ;; the currently selected light
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% s/ Z* |5 w& C: `1 Z& A8 P' I ;; patch agentsets, B1 V7 [- R) b) _/ _
intersections ;; agentset containing the patches that are intersections
" w* H7 h6 l' O2 u) v a* K roads ;; agentset containing the patches that are roads
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turtles-own
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9 E$ f) B0 ]! V7 _ speed ;; the speed of the turtle; u4 {5 `. ~) l, B% ?. X; P
up-car? ;; true if the turtle moves downwards and false if it moves to the right
f" T O/ y" L4 R 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
& ]( r8 t: V, G! i* [ green-light-up? ;; true if the green light is above the intersection. otherwise, false.5 g9 U$ G5 O! K/ a4 G: b( Q* W
;; false for a non-intersection patches.
F1 i2 h5 l/ ~ my-row ;; the row of the intersection counting from the upper left corner of the( [1 U6 n0 d ^7 }0 e
;; world. -1 for non-intersection patches.7 U0 o+ F, F6 ^" d8 p
my-column ;; the column of the intersection counting from the upper left corner of the' C% }: U: B5 J, O
;; world. -1 for non-intersection patches.& I1 |+ ?7 H: _" y; a! X
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
. P `9 z7 {0 q1 N0 a auto? ;; whether or not this intersection will switch automatically.8 k1 [& c0 p1 f0 i+ A+ E+ ^9 U* J
;; false for non-intersection patches.: w4 b4 |8 F+ j% N
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;;;;;;;;;;;;;;;;;;;;;;
" @/ x1 B+ w! s$ F, j- D! q;; Setup Procedures ;;8 N+ \) Q) F5 q& M0 X: B
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* x; p" J+ u& Y P$ X$ m! z;; Initialize the display by giving the global and patch variables initial values.
3 |6 X5 {" R' |0 z4 O3 W4 y;; Create num-cars of turtles if there are enough road patches for one turtle to7 c7 C0 ^4 z$ L- A2 C) _: Y% O
;; be created per road patch. Set up the plots.! o$ _7 i z' c% q! e7 K, M& N: d
to setup
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setup-globals' ]5 y* p) M0 L9 L' ~+ W
2 {+ c# k1 N% A ;; First we ask the patches to draw themselves and set up a few variables
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make-current one-of intersections
7 w; j0 s5 B4 T6 F label-current
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7 F. Q# a' L# E4 O: m% O- j% t set-default-shape turtles "car"
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if (num-cars > count roads)" L R8 S$ o) E/ T2 \: Y( B# q' z
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user-message (word "There are too many cars for the amount of "" ~& H0 x$ H: G* N3 V4 b
"road. Either increase the amount of roads "
3 S% i! ?4 y: o4 V5 ^3 r "by increasing the GRID-SIZE-X or "
B% {4 r3 @- q "GRID-SIZE-Y sliders, or decrease the "
, `: a, v8 S: u C "number of cars by lowering the NUMBER slider.\n". C* z8 T, C9 P {4 u5 O
"The setup has stopped.")( E* Y0 B9 q) R+ k( p! C8 B" v4 E
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
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setup-cars2 i* s6 ?. J) A$ B& J2 r& s( M
set-car-color
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;; give the turtles an initial speed& {& T5 {; |" ]- z/ \
ask turtles [ set-car-speed ]8 W) u& \7 L$ n
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reset-ticks
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1 C# W2 q+ E$ X# b0 D" g2 g+ N;; Initialize the global variables to appropriate values; n3 g& W8 i N& o A
to setup-globals
4 f& k; u8 R H3 g5 m# j set current-light nobody ;; just for now, since there are no lights yet
" M n' ~1 Z I5 m2 w set phase 0& w' n0 t0 l$ D- G2 r ~
set num-cars-stopped 0- b2 d6 b; ]8 e* k: o: C
set grid-x-inc world-width / grid-size-x; h$ i9 T! s" b) y
set grid-y-inc world-height / grid-size-y4 R6 v) q/ T! J2 B% y% v4 O
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary" ?( I1 q: }2 Y, i$ N7 c3 Y
set acceleration 0.099- q, g6 Y6 @1 s9 r- ?* B7 R
end
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, p4 E5 A$ g4 X' ^7 X" w$ I;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ `; y- h+ e8 X! l% x: R
;; and initialize the traffic lights to one setting% O5 t) f) r9 D" k3 [6 k
to setup-patches
7 @9 ~0 r7 l) f0 i ;; initialize the patch-owned variables and color the patches to a base-color
2 {, Y: f/ F' b$ s9 B! Y ask patches" C$ g) w: K( q) K7 g! X
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! v+ F- O# S7 g; t9 T set intersection? false3 Q2 Z. h! V' `2 T5 A- Q6 t4 ~- l
set auto? false
, y" m! }% `2 i set green-light-up? true% }0 `: w' f& l: J
set my-row -1
' |. o/ | K; d* g( c& V! a# A8 v0 k set my-column -1
5 }8 [! M' R( h& D5 h set my-phase -19 J# Q F% j3 K" J3 i& s
set pcolor brown + 38 S0 L# ^/ \3 @. f- D' Q& \
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4 Y9 d6 ?+ a6 K6 O. c# G5 G ;; initialize the global variables that hold patch agentsets/ O5 ]+ @5 e9 D: A; ^4 E; k! n
set roads patches with. z7 z- D" @3 a, o2 U+ U, n
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' m6 E: Q- w. \ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]- S" p* P z% o: R4 |$ T
set intersections roads with! U/ v% \) ]: r8 J8 X, L! t
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and4 E) R. Z3 k" l' q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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! k% z' Y- J8 N2 l& e9 n9 H ask roads [ set pcolor white ]
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end. G% |3 w" s2 n# S/ v5 Y' Z
其中定义道路的句子,如下所示,是什么意思啊?
; b8 |+ n' s/ ~% w( L set roads patches with1 g) A4 u. b# m" W% n& ^: d1 b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' ]% G9 ^* h0 J6 v2 D (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 n/ W5 f2 j- ?4 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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