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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。7 f; f5 T. o4 Z- {2 J. b% Q: r
netlogo自带的social science--traffic grid这一例子当中, W, g$ b& H H, |8 i5 V2 S1 z
globals- ^& H- o" k. F7 h; x8 {7 L
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grid-x-inc ;; the amount of patches in between two roads in the x direction% V6 y0 j3 x$ V: f. R7 \
grid-y-inc ;; the amount of patches in between two roads in the y direction& v5 o0 h9 r- c/ D' K! i
acceleration ;; the constant that controls how much a car speeds up or slows down by if
1 ^' x/ K: h# Q( l+ y ;; it is to accelerate or decelerate
$ M2 c! v n* ^: x phase ;; keeps track of the phase! c5 f' N8 X5 V
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
2 x3 c+ L& b# _* t0 c; M current-light ;; the currently selected light* G# E+ j8 |5 k% J
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;; patch agentsets
) ]. M! m) m0 e intersections ;; agentset containing the patches that are intersections
3 u M) G% K, L" A) _. @ roads ;; agentset containing the patches that are roads5 k6 L& y% Y/ v3 V- t4 N, Y' k5 K
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* l; i2 u' m! L2 B* }0 X& aturtles-own
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1 b0 b7 U7 S4 D" e* T speed ;; the speed of the turtle
, f [7 Q. f; k. h+ w0 ]/ Z) G up-car? ;; true if the turtle moves downwards and false if it moves to the right7 Z" g. p3 e0 J* N8 t5 R% G
wait-time ;; the amount of time since the last time a turtle has moved, w! `) T! S' l# x( W. M& ?% h
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' c9 U3 i) S& a4 T: M) w/ R& @( {patches-own
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intersection? ;; true if the patch is at the intersection of two roads
/ \1 ~% I6 s! x3 L green-light-up? ;; true if the green light is above the intersection. otherwise, false.- K; W7 K& t" S4 U$ I
;; false for a non-intersection patches.+ u; ?$ Z+ P9 }
my-row ;; the row of the intersection counting from the upper left corner of the
' u0 Y1 c) s2 w8 \6 R+ q$ l X1 i ;; world. -1 for non-intersection patches.
# d, |& [ S0 n7 C6 y6 u: B* ]8 h my-column ;; the column of the intersection counting from the upper left corner of the: J. W3 ~) [, ^% ^" ~
;; world. -1 for non-intersection patches.
4 @) Y) h0 v) e9 p/ u my-phase ;; the phase for the intersection. -1 for non-intersection patches.
* P$ L1 D' d' u- c$ ` ]6 h auto? ;; whether or not this intersection will switch automatically.( P8 I m0 ]. N. b& Q
;; false for non-intersection patches.
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& a7 V9 V( c' n;;;;;;;;;;;;;;;;;;;;;;
9 X/ h4 \/ M% f! Y# K. b7 o;; Setup Procedures ;;3 b# x. C; }7 n) B1 x4 A
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.0 \4 N1 T( @0 M' M9 g, ^
;; Create num-cars of turtles if there are enough road patches for one turtle to
8 }/ j6 H m$ j. s: o;; be created per road patch. Set up the plots.% D6 v% |# n# U+ B& O1 \7 F1 v
to setup
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/ G) O8 M+ B* {5 n3 H8 n% b/ | setup-globals3 O5 C1 E- C8 u! g! w! S2 h
) A! { k ?; L/ @6 C2 l ;; First we ask the patches to draw themselves and set up a few variables
9 c( h# F7 Y, _( p setup-patches
# P( H- I% R0 F make-current one-of intersections
# g& L0 T7 W4 @. L4 ~7 c! t label-current
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set-default-shape turtles "car") A9 ~4 J. M1 E( x# h0 J0 Z0 d; y/ ^
3 K' o- M; D: Z2 @ if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "- Q" b* e, \# l6 U$ x. g$ x
"road. Either increase the amount of roads "
+ m5 h9 }; B% z "by increasing the GRID-SIZE-X or "' x, M. L! c# E5 Q! A# s$ f! p4 {& I
"GRID-SIZE-Y sliders, or decrease the "+ ~1 q, g A! t. l( `
"number of cars by lowering the NUMBER slider.\n"! [) B! {) z: }8 ` v& e7 \
"The setup has stopped.")" O% e3 S/ E" c" k8 O; @! D6 t
stop5 U; R* N; c# \9 I# P
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- G" k. x# R: Y5 q ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color6 _! K' ^, K$ t" W1 t7 H$ f: a
crt num-cars4 }2 r) t, ]# Y) |$ d p+ r( T3 S
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% {: p+ k! h0 r' w setup-cars$ A# t' o& ^, a
set-car-color- q. F: N4 x2 I* }1 u
record-data
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;; give the turtles an initial speed) H; p! j6 X" P" j$ `! w
ask turtles [ set-car-speed ]/ M$ [ F) t+ y3 S9 r$ h
0 _2 _0 ~7 T9 [7 N reset-ticks3 W4 x3 b9 h2 [6 T- i- \- ?4 J! ^
end
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) D( b* D, l# e1 x7 L8 {;; Initialize the global variables to appropriate values
9 J, P& |" Z( Q9 ?$ b, Y$ R% a5 \4 K% nto setup-globals
6 g: r4 W- d4 l5 t2 Y set current-light nobody ;; just for now, since there are no lights yet
( ~: V r f" a- B' v, X set phase 07 l8 Y, h$ ^1 e+ ~$ g8 h
set num-cars-stopped 0
3 T# F4 |) [( {2 d5 E7 f! U1 v set grid-x-inc world-width / grid-size-x5 J6 p& f* k5 ~3 C5 x% Z# |* j) ~
set grid-y-inc world-height / grid-size-y
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, h3 `; V# C9 L n! n ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
8 P7 B. b6 o* O! k set acceleration 0.0993 O+ p" F( ~2 _& [& ]" N
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
* A2 R* c R) }. n5 d4 S# X7 @) R;; and initialize the traffic lights to one setting) z0 _2 i+ r6 a1 ^9 l0 c* l/ [
to setup-patches* ]' ?2 N d+ Y' f7 s
;; initialize the patch-owned variables and color the patches to a base-color% G# L# g0 V! C* H _8 v9 R
ask patches
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set intersection? false/ `$ H7 Q [, ` h
set auto? false1 {' w- z* @% E- K
set green-light-up? true
7 s5 A4 W' C& o set my-row -1
# _6 \5 v' F8 {: G$ g' t set my-column -1
; V. M/ q4 \3 W. s4 U& B0 v; T set my-phase -1
4 O5 x/ \$ C% s0 | set pcolor brown + 3
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# P( M3 e1 S9 @! K* ^ A4 ` ;; initialize the global variables that hold patch agentsets( A6 w8 ^' ]: v# P8 I& v
set roads patches with
( I1 j. `+ m; g [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* H' d: B4 N" p) b& f1 _4 g d (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# x5 q' L- ?9 ^ set intersections roads with) u/ Z5 {& |7 T' Y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
- y8 F& r9 ~4 ?* u6 m) B5 K0 z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ v' s# m5 `% X( T
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ask roads [ set pcolor white ]
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- Q0 c+ K* I% E, o3 t" Y7 |其中定义道路的句子,如下所示,是什么意思啊?
) ]* N/ J- [6 d% G set roads patches with$ G4 ]+ t+ C, N" p
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- U- t% u3 s; Q) m" `* @, V- | (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) {. d. v5 k+ H0 G$ [
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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