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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。0 r4 ^5 K5 p; m$ f0 ?" }
netlogo自带的social science--traffic grid这一例子当中,6 y! b$ B3 r3 w1 i9 I+ U- [
globals7 {. g3 s/ E1 A6 c$ m1 p6 M: t. h
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grid-x-inc ;; the amount of patches in between two roads in the x direction3 m0 g) m( y8 N" d4 E9 C. P7 U% p! h
grid-y-inc ;; the amount of patches in between two roads in the y direction
: g/ y# E4 V6 M4 ^2 {+ ] acceleration ;; the constant that controls how much a car speeds up or slows down by if
3 Z; _, }$ L4 e% B# x ;; it is to accelerate or decelerate [/ F6 H {$ i
phase ;; keeps track of the phase7 W: i# e, c, v- M4 F) }* g
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
) E9 S M# Q! l- g# U+ F0 v9 L' Y current-light ;; the currently selected light. s- B5 q; j$ ^& {; C4 j
) Y: G/ E3 {, f# t" i6 { ;; patch agentsets
2 q v6 k. D! i7 D: b* c4 o intersections ;; agentset containing the patches that are intersections3 ], q" x$ r ~) n/ V+ y2 `$ y& E
roads ;; agentset containing the patches that are roads0 z- r/ a+ h; k# f6 f) L/ a7 v
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+ L9 X5 v9 W2 Z. zturtles-own% _5 [- ^2 @6 |# }
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speed ;; the speed of the turtle
( I9 W$ q: a& Z f, g v up-car? ;; true if the turtle moves downwards and false if it moves to the right
% d5 b0 X3 O# {1 z+ h7 J1 O# G wait-time ;; the amount of time since the last time a turtle has moved
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2 M' {- j, v# S9 M/ |patches-own; d9 D8 J4 D& A- r7 ^7 P! }' ]+ o$ t
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intersection? ;; true if the patch is at the intersection of two roads0 E7 ^* S( g0 K' u, ~' P
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
8 H0 V9 V$ {. b3 x* y3 R ;; false for a non-intersection patches.
3 i+ x0 ~" x6 O my-row ;; the row of the intersection counting from the upper left corner of the) N4 _' h- t) o) C3 l' l& @
;; world. -1 for non-intersection patches.- I- U7 u3 g0 h9 Z/ a+ z
my-column ;; the column of the intersection counting from the upper left corner of the
( X: f9 C+ g$ R ;; world. -1 for non-intersection patches.) _* b. E; q% ^: t
my-phase ;; the phase for the intersection. -1 for non-intersection patches.9 D6 [; ~2 ?/ A
auto? ;; whether or not this intersection will switch automatically.
1 s9 M6 l S/ ^. U ;; false for non-intersection patches.% ^, m/ S0 X- Z( D
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;;;;;;;;;;;;;;;;;;;;;;9 S5 H" R. W, `
;; Setup Procedures ;;
1 a: O1 }( a$ E;;;;;;;;;;;;;;;;;;;;;;) D* Y/ z" A3 q; s
, T# H8 `) z" y; ?+ p- I: w3 |;; Initialize the display by giving the global and patch variables initial values.
( B; h; a; t( r9 r;; Create num-cars of turtles if there are enough road patches for one turtle to
/ o& n: K" b, B2 Z;; be created per road patch. Set up the plots.
. Z. c- h T" R+ [& rto setup
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setup-globals
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, ~; y. ?5 g( X8 i0 m7 R P ;; First we ask the patches to draw themselves and set up a few variables4 D2 G' [% M( D* z3 e, ?
setup-patches
) _; i: v6 G# ^' f make-current one-of intersections
5 t- I5 r& {4 @5 U4 G label-current- {- [ x% D" S
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set-default-shape turtles "car" N# s: X) Y1 B' h' I2 { l. K8 I5 h+ p
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if (num-cars > count roads)! [9 T5 z+ T; z% F2 N
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user-message (word "There are too many cars for the amount of "; Y. p! T3 N" l+ i+ b
"road. Either increase the amount of roads "; b3 ?6 f. M4 P- n0 G6 l9 @, g
"by increasing the GRID-SIZE-X or ") g) o3 l0 [! u1 i& }' U
"GRID-SIZE-Y sliders, or decrease the "
. a) S3 p9 G6 O3 J/ I "number of cars by lowering the NUMBER slider.\n"! n7 H& K& [2 M* Q0 p& K" D
"The setup has stopped.")
5 o5 n, b0 ~0 W# q+ S0 _6 L stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color/ ~4 h$ M& ^/ L# A
crt num-cars
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- `/ E) y5 l0 V# K4 T, R. c setup-cars- Q% _" a# i U* x2 z# W( {* N! F" K. Y
set-car-color
# O' _" J* \ @/ R- v4 }8 R record-data
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2 w, L- Q9 l% P' B6 @; i ;; give the turtles an initial speed
K5 V1 B0 N0 Z( y: Y: u3 W4 K. @$ K ask turtles [ set-car-speed ]2 t& \+ P% B" K% j
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reset-ticks
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;; Initialize the global variables to appropriate values
: m# l" r) q7 xto setup-globals# G! R2 M8 _+ f7 f
set current-light nobody ;; just for now, since there are no lights yet
6 v: d$ ~; A# z: h1 T8 l set phase 07 S$ Z8 V q# W) ]! g
set num-cars-stopped 0" p- I" t: s: O/ ^+ y7 T9 l9 \. Y
set grid-x-inc world-width / grid-size-x
7 w& _- O" k) C& I8 |# y+ V4 I set grid-y-inc world-height / grid-size-y' L/ c5 G0 h/ A* S- b! ~
8 x9 W% L7 x) W" y" p ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
& F1 q' e( S' w9 W; n set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ r3 H1 G, h6 E2 W g
;; and initialize the traffic lights to one setting
# u) p O. L9 I6 V& D8 w0 ]to setup-patches
5 y) ?# C" A) [5 B ;; initialize the patch-owned variables and color the patches to a base-color& H* d/ Z& o0 G
ask patches) z4 j5 x4 ]* ?8 ]" b3 }
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set intersection? false
3 e; B% [' V* ]/ n' k' H6 h set auto? false
: n" t/ r' y6 `! H6 ~! p set green-light-up? true
" j8 k3 q V* o, {: \ set my-row -1
' q# S4 n4 |5 A s. @2 L set my-column -1
! ]7 E" u* D5 M set my-phase -19 n3 n( s2 C9 e( u1 O/ J
set pcolor brown + 36 b H; ?+ G9 m. _& z- T1 l
]
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4 Q% m4 Q3 R! u: i* r# H ;; initialize the global variables that hold patch agentsets
+ v$ v( }2 P9 e7 C) T0 B set roads patches with2 E9 o2 w9 w2 n* L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 ?& ^+ ^- y- B! \
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ G4 q5 _, H; x. a
set intersections roads with9 U1 ~1 z. ^, r2 Q" B! J2 |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
% r; V8 G) I: X# o6 M- b2 I; w (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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/ U- I$ I4 _1 V* D# G; s) d$ D ask roads [ set pcolor white ]
* a0 A0 c! @8 @$ r. j2 J setup-intersections% Z( c5 O2 u2 \- Y+ \
end# y L W0 O1 p' P6 A
其中定义道路的句子,如下所示,是什么意思啊?9 N- ]7 D8 N* Q
set roads patches with5 h0 @4 \' M% I6 g8 H
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 i, W7 D$ P7 i% A' T
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- ~3 D3 S5 R+ q$ G" c6 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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