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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。
* ? B; \* @6 t3 A! Rnetlogo自带的social science--traffic grid这一例子当中,3 E/ \- z( e8 v
globals
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6 t/ Y) a2 W8 S1 w Z5 t7 k grid-x-inc ;; the amount of patches in between two roads in the x direction/ S2 N: E+ o7 W8 w* [7 v Q" z
grid-y-inc ;; the amount of patches in between two roads in the y direction9 T% o; p5 |. `% d4 J. r
acceleration ;; the constant that controls how much a car speeds up or slows down by if
; X2 q i9 e' n9 _9 c0 F1 d7 S ;; it is to accelerate or decelerate
" u# `/ _) v, ` phase ;; keeps track of the phase
# w, r% k, q6 a1 y$ f' d7 d num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
5 E+ `& P& ]. a- B9 t+ f8 Q current-light ;; the currently selected light8 x% s! \" |( e- @8 L o7 N1 G
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;; patch agentsets
# n; x" I u/ J/ E intersections ;; agentset containing the patches that are intersections
) C3 U: O$ ?- e0 X" g6 }- x3 L roads ;; agentset containing the patches that are roads
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turtles-own8 v5 {4 A a' U" T+ j/ W
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speed ;; the speed of the turtle Y% G3 T+ L, n! ^8 U4 R, l. R
up-car? ;; true if the turtle moves downwards and false if it moves to the right
5 I. K% }; ~8 M E& c/ F wait-time ;; the amount of time since the last time a turtle has moved
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# ^! s/ Q3 x# |% z# W1 l4 n& Ppatches-own
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5 ]: E) K# v5 g( ?7 A intersection? ;; true if the patch is at the intersection of two roads. t/ X# T9 o: V p2 Y
green-light-up? ;; true if the green light is above the intersection. otherwise, false.7 ^; z4 [) \/ \/ {, @( F
;; false for a non-intersection patches.
% c2 I, _# v! z% f my-row ;; the row of the intersection counting from the upper left corner of the5 s' {3 a' B1 @) f& y. X
;; world. -1 for non-intersection patches.7 A3 \$ y3 w1 P8 x: P1 X
my-column ;; the column of the intersection counting from the upper left corner of the {2 k* P5 i# G. r& i0 o
;; world. -1 for non-intersection patches.5 f; z, \! w: {6 A& f
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
0 K' G! }8 M" }4 d, C/ k auto? ;; whether or not this intersection will switch automatically.
1 r K7 t! n" @/ D2 a( o6 P ;; false for non-intersection patches.
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" c- j9 B+ \5 r ~;;;;;;;;;;;;;;;;;;;;;;( ~9 i7 B" |* v/ T0 _/ J6 H
;; Setup Procedures ;; ]' w% F% W, T+ E2 j7 T" Q
;;;;;;;;;;;;;;;;;;;;;;
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0 `( X" N$ ~+ a6 h8 r;; Initialize the display by giving the global and patch variables initial values.+ w& Q" G) c7 F6 H# v- s
;; Create num-cars of turtles if there are enough road patches for one turtle to
% }9 O2 W/ E5 ~: }* H; ^& Y0 \;; be created per road patch. Set up the plots.5 Q; @9 J% ` c4 g% O7 S
to setup/ ]1 L+ y3 l6 ^
ca
0 @) S) k$ p$ a3 T setup-globals
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$ o$ h2 r' T0 s7 H. p$ S7 O( @7 i4 Y ;; First we ask the patches to draw themselves and set up a few variables+ g5 j6 m( v' W# k
setup-patches3 x5 i) i' ^2 j0 I+ i3 }1 b
make-current one-of intersections
5 @6 v( U+ i. K8 @ label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "' P0 F/ w$ \! Z6 f9 n: y
"road. Either increase the amount of roads "
% }: Y- ]& r( ^1 b$ H6 z "by increasing the GRID-SIZE-X or "- _* p$ \7 ^/ L
"GRID-SIZE-Y sliders, or decrease the "
9 @2 R1 D! u1 u3 @& S* _ "number of cars by lowering the NUMBER slider.\n"' R4 a9 ?, S7 H& b% U' I
"The setup has stopped.")6 G( z0 `5 V. S* s& E& ]' O
stop
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& V' s1 @( H/ l+ F% n$ V ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
+ L4 q! \( s6 |0 U crt num-cars6 t3 D1 z; U8 I
[
7 r! x: z& \# W9 G/ { setup-cars
7 a% t9 n+ O7 ~ set-car-color
9 E% b: J3 w' Z0 ^) Z record-data
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$ j, }' y& Z( Z0 ] ;; give the turtles an initial speed
# o# l% Z* E' r2 x2 g ask turtles [ set-car-speed ]. r1 w7 n# C% |8 a+ t1 A) N. M
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reset-ticks6 }% V. {: I0 R* R
end
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;; Initialize the global variables to appropriate values8 L: Y/ S3 s$ q9 B- y
to setup-globals- \5 q# s1 I( G4 z/ x* H
set current-light nobody ;; just for now, since there are no lights yet* z2 D* x' A) _& O! d! e
set phase 0. S( u" h; g3 b! \# c* t" L! R& _
set num-cars-stopped 00 {4 V! d, ^% Z. q
set grid-x-inc world-width / grid-size-x
! x" o/ p# X4 j 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
0 N/ l' k2 t- f" ~; E \& m3 T* N set acceleration 0.0996 v2 R6 b2 [5 _$ u8 E- ?$ F" q
end% g: ?- `, U$ e# c z
' ^( p% ]+ q# z% M+ y+ S P;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
0 t' M3 v5 H+ g3 d; ?" B;; and initialize the traffic lights to one setting
3 Z6 H& i# D" pto setup-patches
% \& q( M l; P! Q0 h: e8 _8 b ;; initialize the patch-owned variables and color the patches to a base-color
; N( i& O2 h0 d! e; |- t ask patches
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1 o2 T' U6 Y7 t4 G/ }7 D. R1 v L set intersection? false
3 `1 W5 n) F. ]8 i0 s5 ^* A set auto? false& g3 \* f4 U; w0 p
set green-light-up? true
2 n: ?- H2 M, U% t8 T$ P set my-row -1' @2 S/ o4 v: @% _
set my-column -1* @& W# B( ?4 I0 ^+ r4 o7 d
set my-phase -1 R- M5 A( [, s7 h7 F
set pcolor brown + 3( L; Q) L/ c T, j+ Z6 V
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;; initialize the global variables that hold patch agentsets
) T% J) Q, G8 ]9 e* y1 V set roads patches with
Q6 a# z& Z( o& j3 L6 G" g [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 [3 V$ v) Z2 R" M (floor((pycor + max-pycor) mod grid-y-inc) = 0)]" C. x1 d( X3 L7 ~0 s7 r
set intersections roads with" I4 ]$ n2 ?: z) g# j# S
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
! X7 R2 \ L! T+ Y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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end
; M) K [+ g% }其中定义道路的句子,如下所示,是什么意思啊?
9 U4 }# M T% a o3 ~' z set roads patches with; S& j( q- L6 v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: [$ q0 d1 n2 _$ r+ y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. ]5 B* R* J4 a' ~ n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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