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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。4 i' S) {6 U! e5 B) L$ K8 r D
netlogo自带的social science--traffic grid这一例子当中,, O- K% P& q# t4 S, n* V
globals$ O. t! j- k5 h8 \) E5 L3 T# W
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7 ]$ ^0 @$ _3 r# u" O' _2 }7 E grid-x-inc ;; the amount of patches in between two roads in the x direction s* M7 p" \7 V
grid-y-inc ;; the amount of patches in between two roads in the y direction! K# c$ Q8 H1 Y) L3 P* q, g
acceleration ;; the constant that controls how much a car speeds up or slows down by if
& S- u/ M/ |% z! @ ;; it is to accelerate or decelerate
" |: d) N5 a4 _- J; V& ^# \: a phase ;; keeps track of the phase1 B; A" S, |) b) \1 w
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
3 Z9 Y( g6 a7 a current-light ;; the currently selected light
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;; patch agentsets2 A% L- c' s* K: S( w
intersections ;; agentset containing the patches that are intersections
; O5 y( A# V# c& q6 u roads ;; agentset containing the patches that are roads
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turtles-own
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, }) e1 Y+ E$ c. S speed ;; the speed of the turtle$ T: [( E6 e0 s. T
up-car? ;; true if the turtle moves downwards and false if it moves to the right
3 Y1 N3 I4 D* W }$ r: C wait-time ;; the amount of time since the last time a turtle has moved, p: J/ ?2 u, V+ ]
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patches-own W3 [( F* Y9 e; L+ s& b% {
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intersection? ;; true if the patch is at the intersection of two roads/ h0 N( q, }* S" Z3 {, g
green-light-up? ;; true if the green light is above the intersection. otherwise, false.3 }) i+ W& w' C' ~/ l' c
;; false for a non-intersection patches.; W/ `5 H+ | R# H
my-row ;; the row of the intersection counting from the upper left corner of the
. x6 t2 ~# j( [1 ~5 K0 [1 W$ k ;; world. -1 for non-intersection patches.
0 Q8 ]" }: _6 }( d my-column ;; the column of the intersection counting from the upper left corner of the3 l6 M9 J# q) N3 l) R/ V" b
;; world. -1 for non-intersection patches.1 S# R3 q1 `+ S: W& d. D/ n
my-phase ;; the phase for the intersection. -1 for non-intersection patches.4 o! R, {' A" S: s
auto? ;; whether or not this intersection will switch automatically.
0 r1 }9 H' j0 l) v& d ;; false for non-intersection patches.$ H; [8 b! N! Z. {
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;;;;;;;;;;;;;;;;;;;;;;
( L" o+ \( j* G( B;; Setup Procedures ;;
, J! M! g e5 e r0 J8 Y; Z1 r;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
, V/ @: [$ e0 ~6 i+ {;; Create num-cars of turtles if there are enough road patches for one turtle to
8 a9 z6 c# A q7 I;; be created per road patch. Set up the plots.: Z( ?4 u% j; J8 c+ G
to setup
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* O1 P% K, z8 y setup-globals
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4 B4 ?% d% y: ^; I3 P ;; First we ask the patches to draw themselves and set up a few variables
% W- d6 v: s% M* [8 a. f# }( { setup-patches
9 B9 A5 w9 A& P. E make-current one-of intersections
m6 N' \; ^1 X9 {/ J; n label-current
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7 u5 x { w- \+ M |( N set-default-shape turtles "car"
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; B" ~ l) |; k+ O3 t if (num-cars > count roads)* A5 W4 ^: i/ ^% ~( }
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, `* g' h1 |. `" T* P user-message (word "There are too many cars for the amount of "4 V* D$ F9 S( @) u4 P
"road. Either increase the amount of roads "
$ o9 p7 }* d9 d0 v "by increasing the GRID-SIZE-X or " T" q" L0 m4 k Z
"GRID-SIZE-Y sliders, or decrease the "3 O, J9 D* t6 H9 [0 e
"number of cars by lowering the NUMBER slider.\n"
, }) U% M" g0 `& Z "The setup has stopped.")3 F1 M/ b! q- Q, H3 k6 b7 H% d) @
stop& i* U8 K/ Z& O' b
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color y3 c' G0 ?5 l$ q. Y
crt num-cars
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setup-cars
: e0 ~# |6 z3 p( L$ ] set-car-color
6 _: B: V' K. U* {/ N& w record-data
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, F) Y3 W. H! n+ ? ;; give the turtles an initial speed
+ E- r7 {8 }" d ask turtles [ set-car-speed ]
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reset-ticks" _' ~4 C2 \, k i5 F2 X
end1 l6 {) b+ x9 p+ o
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;; Initialize the global variables to appropriate values; v& G3 S* e- ^6 b
to setup-globals1 _: p9 a4 H0 u, K/ Z) A* F
set current-light nobody ;; just for now, since there are no lights yet
7 t9 K4 D' [0 f+ x7 B4 N/ Q/ R set phase 0
6 V/ l: d9 T) G/ p set num-cars-stopped 09 O: o2 l) N7 |
set grid-x-inc world-width / grid-size-x* n* o4 E7 i* b2 b- Z! [$ N1 s' u9 Y
set grid-y-inc world-height / grid-size-y
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$ t' k2 [: I- t, R0 O9 J. V ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
$ Q+ H9 ^5 w4 T$ K, d# P* y* x set acceleration 0.099
) d V, |% Q: {( mend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
# _! @9 ?4 v/ m- `;; and initialize the traffic lights to one setting$ J; u4 P" n( A, c# E
to setup-patches
2 F% L9 g6 U3 p0 ]; I ;; initialize the patch-owned variables and color the patches to a base-color
. A7 T3 \! j5 n+ j. [+ C9 T l ask patches
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. D1 q. Q9 k1 Y1 h3 @8 Q& H set intersection? false
' L. j' @1 h5 }' U+ y* }* I set auto? false
( B5 j1 x% T1 q, r$ G set green-light-up? true0 v) T. |5 a+ S1 W8 v1 t
set my-row -1
' F' Q- F9 I+ Y0 w. V) Z( g set my-column -1: \! r' p% Z# c( |2 F
set my-phase -1
7 Y4 v4 @, ?0 U- H set pcolor brown + 3% Y& ~. ]' I1 r& ~9 m H* j
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/ v3 x. b8 g, G, Z9 s9 ^ ;; initialize the global variables that hold patch agentsets- [: e3 M! }+ [1 o4 q% n) v; }: s6 Y
set roads patches with
' `3 L( ]5 h9 w7 L [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 k4 C6 h. e4 Z* y4 K2 g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 d7 g9 T0 Y9 N3 O( B set intersections roads with7 I) G6 w h9 g) @7 x
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
) u5 k/ F+ a! H (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( C7 b/ f# f' ?; \$ }
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ask roads [ set pcolor white ]) ^4 n: g C8 @3 o3 {
setup-intersections) a5 b2 [1 b' I1 b- q
end
' n& k2 Z9 P3 x T6 Z: ?其中定义道路的句子,如下所示,是什么意思啊?
' x. @, `! f( J- o- B set roads patches with% j$ h2 o8 t2 U8 q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
. E- T2 ]5 |0 E+ B1 s9 h (floor((pycor + max-pycor) mod grid-y-inc) = 0)]! t4 w2 S: c6 X" s/ P) s v
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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