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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。 n3 ~5 ^0 w" V+ a% ]$ ]
netlogo自带的social science--traffic grid这一例子当中,; p, {. @: e- N' w. S
globals6 s* O# m! z" |4 s
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grid-x-inc ;; the amount of patches in between two roads in the x direction
% y: S6 o }7 A% h! L: W7 P grid-y-inc ;; the amount of patches in between two roads in the y direction
% w/ l+ E# X- Z/ g4 K8 m acceleration ;; the constant that controls how much a car speeds up or slows down by if
& G$ o0 l6 H) B! z3 s' D/ o+ O ;; it is to accelerate or decelerate6 A) e: k& r) _
phase ;; keeps track of the phase
1 t8 z& x6 _5 o, d3 M$ A0 p' ~ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
. E/ ` V, ]* N current-light ;; the currently selected light" |; w/ r' z( y1 [+ N5 p
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;; patch agentsets
2 g5 ?9 ?1 g* ] intersections ;; agentset containing the patches that are intersections
' d6 \" N, R5 V) ~0 C2 T8 e roads ;; agentset containing the patches that are roads
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turtles-own6 [' M) I5 N7 `6 |" h3 [
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speed ;; the speed of the turtle+ \0 C: [4 g' C7 _4 R/ I8 a$ C
up-car? ;; true if the turtle moves downwards and false if it moves to the right# o9 T( H7 P6 ^
wait-time ;; the amount of time since the last time a turtle has moved
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, v: b0 C& v2 O# y6 ^patches-own5 p v, c: n! h1 O& o1 T
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intersection? ;; true if the patch is at the intersection of two roads- ?; ^7 g8 z/ x" z9 U7 t
green-light-up? ;; true if the green light is above the intersection. otherwise, false.$ }. ]1 }+ r, u7 D
;; false for a non-intersection patches.
. O, |6 d! @: B8 S my-row ;; the row of the intersection counting from the upper left corner of the8 r) `7 b3 Z* {" ]2 l
;; world. -1 for non-intersection patches.
5 U# b# S. r6 X) l: e2 N my-column ;; the column of the intersection counting from the upper left corner of the$ U3 h4 B, y& v, D
;; world. -1 for non-intersection patches.
4 y5 C2 l$ y) B* I4 F my-phase ;; the phase for the intersection. -1 for non-intersection patches.
% o7 z) j# d/ [ auto? ;; whether or not this intersection will switch automatically.
9 o$ l$ |& u7 x# t ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
. P% p9 B. q8 b, t# [. m;; Setup Procedures ;;
9 \9 ~! [5 M! \# R' V3 p;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.0 N6 E9 }* R$ G' @+ W1 ~) m& }
;; Create num-cars of turtles if there are enough road patches for one turtle to* q8 G5 r: ~* {0 d: i1 Y" Z
;; be created per road patch. Set up the plots.
" W8 Q) p+ N( o+ E A: mto setup
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3 Z6 G) ^! @6 L: q1 O setup-globals
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! w4 P5 P+ s }( s! ]. E ;; First we ask the patches to draw themselves and set up a few variables8 H, f" C" E2 P8 U
setup-patches+ R4 X% k) E# ~$ b+ i' [
make-current one-of intersections
5 u% ~& c& X) q2 A9 @ label-current/ m# B- t( [6 k5 o' x7 [
7 ~/ c7 B6 g$ ~/ [9 d" e3 L8 u set-default-shape turtles "car"0 o- q% N; [4 G G7 C
! S( A s# Z8 W if (num-cars > count roads) a, k- z5 p9 C/ }4 f
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user-message (word "There are too many cars for the amount of "
4 _, W ^' B6 w: Y5 b "road. Either increase the amount of roads "' z9 l+ q" }% |$ k# [2 U7 ^
"by increasing the GRID-SIZE-X or "
k: p) q0 J9 `# G+ @; P "GRID-SIZE-Y sliders, or decrease the "4 I7 J1 @) \( a9 ^! j h
"number of cars by lowering the NUMBER slider.\n"
! p& V+ z0 A/ _% S "The setup has stopped.")/ J6 y ^) j7 |" r* E- }
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color; C# I/ T- O' }- T0 @
crt num-cars
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setup-cars
; [. }. N& d8 i# Y' Y7 @1 L set-car-color
) U- |( j. a7 P5 w7 k7 L7 p record-data
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7 {9 `# v4 n' `" f! J; A7 |0 { ;; give the turtles an initial speed% N6 s$ B3 F# M, D, A9 `2 \; n
ask turtles [ set-car-speed ]7 }& U2 a4 N( S5 ?2 q. | r
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reset-ticks: ^5 b" M; K9 t: e o3 ]) F8 a$ P
end2 A, A/ ^: r, G8 [ G0 T: d$ O
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;; Initialize the global variables to appropriate values- Y* b8 m' n# Y! {4 O2 S% M
to setup-globals& ?$ r& B8 V. l- G0 @) n$ q
set current-light nobody ;; just for now, since there are no lights yet
% j5 M D; {& n7 s7 Q' W* n set phase 0. K8 H) p" o) Y; H ^- s" b
set num-cars-stopped 0
9 D7 B- v6 g- B3 @6 }& R9 A set grid-x-inc world-width / grid-size-x
# S y5 m8 X7 x9 [& A 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( Z# p* A, S7 g# F# A
set acceleration 0.099
- k7 k" e& P" I, oend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,# z% V R2 ~$ v+ T
;; and initialize the traffic lights to one setting
4 L7 c5 t+ ]1 @2 V: ^$ `to setup-patches5 s$ }- ^* S2 e! ?
;; initialize the patch-owned variables and color the patches to a base-color( `2 I @ h) E# K" s4 F4 f
ask patches
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! o3 V+ L" v- S: ^$ Y$ b set intersection? false) v, o: b, A' S4 ?+ M
set auto? false
3 _, [3 _* r% A& \( n set green-light-up? true( U# ^4 t9 f4 g- T+ U0 P
set my-row -1 \+ a4 h* ^! M
set my-column -14 d: t3 F6 m, b2 |8 c* K& A9 n c
set my-phase -1
1 |! ^$ ]# E4 E5 d set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets. ]: \, u3 d& d7 G8 p& j
set roads patches with
0 o/ j- ?& W* m( N [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( Q' t) R, |& d7 c6 M; o+ q3 n% _
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]* b% |( w5 w* W( |: B
set intersections roads with
7 R% ]6 _: L- ~- p2 G5 U. @ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
! s: Q( P4 s7 E# ]% z: N& T. } (floor((pycor + max-pycor) mod grid-y-inc) = 0)], g6 T% K/ ?2 `& @0 g+ W
: ]5 x: a0 \- O2 b* K9 E ask roads [ set pcolor white ]
1 h* U l L+ _, k$ ~2 X setup-intersections1 p4 _& J+ r* x' d, p
end
: h7 f, f! z+ ?: Z+ X7 v其中定义道路的句子,如下所示,是什么意思啊?, e$ k; B( m0 t4 @$ i
set roads patches with8 p9 }* \! l: T4 O" Y8 H
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 o+ G% j S: b, b' ?6 Q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- T0 O- y% M8 O( S. W) s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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