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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 c$ P& n2 g' w; f" {% Z& n0 Y
netlogo自带的social science--traffic grid这一例子当中,, L0 ]2 |! B' b& r1 Z( l
globals0 v" X. t$ J+ n! t
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$ v* _3 N& C8 w i grid-x-inc ;; the amount of patches in between two roads in the x direction( q6 G* d4 t- O) ]( S$ j5 T, I
grid-y-inc ;; the amount of patches in between two roads in the y direction2 G& R" f+ u' ^$ X/ s1 o# l. [/ r
acceleration ;; the constant that controls how much a car speeds up or slows down by if! G4 I& a8 o( B3 Y' L# X
;; it is to accelerate or decelerate, O/ q) e [3 G9 o. i
phase ;; keeps track of the phase
6 u% k! }3 k, n( ] num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure6 Y, y! b4 P- H* x+ ?
current-light ;; the currently selected light; @0 P1 @/ A5 j+ f" M5 N6 n/ L+ e% @
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;; patch agentsets
% {: @$ n# ]. Y8 H. m intersections ;; agentset containing the patches that are intersections
+ R/ Y) n/ W: V" W. d( p' i roads ;; agentset containing the patches that are roads" ?+ |5 C6 {+ e1 l2 t2 V+ Z: t y3 V
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turtles-own
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5 ]" i- K6 |+ [. P' _. w8 ~ speed ;; the speed of the turtle
: e+ Q. z, X4 t) e up-car? ;; true if the turtle moves downwards and false if it moves to the right* v* Y9 i% o) b y
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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* V! b, Q5 e! ^9 ^* `1 q, N) | intersection? ;; true if the patch is at the intersection of two roads
6 u9 a6 D' d0 D* O+ \: r green-light-up? ;; true if the green light is above the intersection. otherwise, false.3 l4 l# y& e% O. R( [! q
;; false for a non-intersection patches., B3 M+ a8 m5 t/ g2 ~- |' u
my-row ;; the row of the intersection counting from the upper left corner of the
0 [2 V& q+ f' c. I( ? ;; world. -1 for non-intersection patches.5 _* n; \: W* d8 ^ |, j& D
my-column ;; the column of the intersection counting from the upper left corner of the' G' Q6 x7 L$ K: ^& ?# {) n
;; world. -1 for non-intersection patches.: C, M* r0 M' v8 ~: l
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
* C9 ^( [: ?6 W* N" v: Q, {) A! D auto? ;; whether or not this intersection will switch automatically.4 v- L$ Y, c' c+ a# _1 p
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;& ~( N: `- d, K+ I% s+ t6 V
;; Setup Procedures ;;9 j# [1 Q y: m Y) |
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;; Initialize the display by giving the global and patch variables initial values." L2 X$ h* P7 h8 J* ^
;; Create num-cars of turtles if there are enough road patches for one turtle to
1 v1 \' }$ U/ W;; be created per road patch. Set up the plots.% R+ [* ~2 O! Q$ h
to setup' C; t( D8 ]& ]4 Q1 \
ca
, C0 n) o! @$ c$ v$ N' W setup-globals
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- _2 p1 D6 R6 F! @! K ;; First we ask the patches to draw themselves and set up a few variables+ p* M# u) D9 u4 [- d
setup-patches
6 ?/ I* N* i* q1 s- q make-current one-of intersections
; r" m- b: R7 r1 r, @$ t1 } label-current
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. b9 N9 j. e. I% q# r% E set-default-shape turtles "car"# U. Y/ a9 s* W5 j- T" @5 V: x
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if (num-cars > count roads) v7 S4 m$ m- O6 [- H7 d4 c6 `
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; S& S+ k1 C. S: |9 y# g user-message (word "There are too many cars for the amount of "
9 A0 p [, k/ e; b3 i2 O "road. Either increase the amount of roads "
0 X7 @4 M, h; c, m9 u( `7 J "by increasing the GRID-SIZE-X or "
. V+ B. u, Q8 m; \! f5 m0 R "GRID-SIZE-Y sliders, or decrease the "* U$ p P$ Y) e3 m
"number of cars by lowering the NUMBER slider.\n"
/ e- ^- [; Z' _* D' } "The setup has stopped.")
% }2 E& x: d; {) | stop
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+ s) }! g. F- U6 Y ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
( Q% [/ Z$ {" F. I2 R crt num-cars: @- u' w$ ?0 ^0 N3 C
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+ x+ [2 V$ q- N setup-cars
3 R8 |" q# L7 s& L set-car-color
! J. ]+ p) p$ S: a; ?6 D record-data
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;; give the turtles an initial speed# j$ _! O# I; A4 Q
ask turtles [ set-car-speed ]
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. P6 ^6 T! H- r4 R$ \! g reset-ticks
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V% O) x) ? y( O;; Initialize the global variables to appropriate values
& m* y1 C$ l; h) Ito setup-globals
& |( T1 O5 X; Z& O! c set current-light nobody ;; just for now, since there are no lights yet
, C/ r1 \/ Y, W7 f. _2 v set phase 0, [/ g; H/ q( j
set num-cars-stopped 0" y4 B7 e9 |* c
set grid-x-inc world-width / grid-size-x
9 t9 E) [5 e; _8 O, q2 d 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! V" J5 E9 M& O: X
set acceleration 0.099
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3 k( y) }8 ~; T;; Make the patches have appropriate colors, set up the roads and intersections agentsets,! @' j, w% P4 D$ O
;; and initialize the traffic lights to one setting
* o2 s6 B9 a# O6 Gto setup-patches Q9 a: \* F8 ~4 X0 Z
;; initialize the patch-owned variables and color the patches to a base-color7 S$ I7 ^& Q9 w% ]3 H7 K
ask patches
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set intersection? false+ ]2 _0 S& r1 I" M$ S4 H
set auto? false& o/ r' E" [1 b/ _, O
set green-light-up? true
; f0 v: G B" X/ B& @% E: Q set my-row -16 y1 T8 Q& a. c/ o* M
set my-column -1
0 a# \8 h/ W4 R5 ]3 }& x3 t& w/ X set my-phase -1
o! k/ }0 F# E* `! g0 C6 U, s( Y( j set pcolor brown + 31 b5 j6 ~ J6 ?: X; k2 h& n
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X* @7 c% s( [* v9 m ;; initialize the global variables that hold patch agentsets) y( o: ?$ V- x/ z; @5 P/ S/ M
set roads patches with
# K% E3 Q! P/ }8 ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; v& E+ b, h# _- ~, g; c
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 d/ j7 a6 J) d: b% S7 R2 A; w4 `! }6 `
set intersections roads with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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- g) d2 a4 f6 g/ f ask roads [ set pcolor white ]
/ M0 h: B2 ?: h: X% l' b& ? setup-intersections( k* t7 k8 g4 `* e# n
end, `6 [" ^" {4 T6 d) Y
其中定义道路的句子,如下所示,是什么意思啊?7 M/ Z' \. J) R- w3 k* u
set roads patches with
& k7 }4 l" x) v [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
& z# F" V y) t! c8 p7 L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; `2 T5 J P5 d4 m9 {& j; f& F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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