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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。3 D& d/ s* @; }5 w5 [1 n1 D: o
netlogo自带的social science--traffic grid这一例子当中,
% F. M5 }: i1 p& t" }/ |3 i& Y! s& Fglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
7 I9 V4 ^; X; T* ~7 X" l! } grid-y-inc ;; the amount of patches in between two roads in the y direction6 {- n1 ]6 f& I6 ^$ w2 l) }/ u
acceleration ;; the constant that controls how much a car speeds up or slows down by if8 F. U; }' O* j2 L
;; it is to accelerate or decelerate
* p& Q8 T& l. L) s phase ;; keeps track of the phase# Q! O! L% w$ u7 O( N; F/ d
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure, V5 w% M2 C* ]8 O
current-light ;; the currently selected light
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;; patch agentsets# S! l1 j. \4 W. M; L
intersections ;; agentset containing the patches that are intersections
( ^* [$ P' u% A roads ;; agentset containing the patches that are roads
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turtles-own. v$ Z6 U) ?3 h6 A$ Z
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speed ;; the speed of the turtle" o. x# A1 E8 \3 Q
up-car? ;; true if the turtle moves downwards and false if it moves to the right; |( q& H/ y) U4 R. N" Z
wait-time ;; the amount of time since the last time a turtle has moved: M, E5 C6 f. B3 X! H
]
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# _- h% ?1 r& Ypatches-own9 H, J7 ^7 M W( J1 h3 T p
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intersection? ;; true if the patch is at the intersection of two roads
" e: A0 b- a, o green-light-up? ;; true if the green light is above the intersection. otherwise, false.8 C7 X; ^: x) ^
;; false for a non-intersection patches.' o3 u. q4 L/ a" N, ^
my-row ;; the row of the intersection counting from the upper left corner of the: c$ i ]9 X# a2 |
;; world. -1 for non-intersection patches.- {* k( t/ o+ o) I
my-column ;; the column of the intersection counting from the upper left corner of the* D5 w0 [+ ]/ g
;; world. -1 for non-intersection patches.! L- x3 n) v- s
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
+ t+ V( J2 Q! z/ w3 b auto? ;; whether or not this intersection will switch automatically.
! X5 W2 v4 P" L7 J! K ;; false for non-intersection patches.# ^6 Z+ N2 \% U0 d: P
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;;;;;;;;;;;;;;;;;;;;;;' n) [5 `3 t Z$ G( [2 Z( @
;; Setup Procedures ;;* _& e( Y* B5 h
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;; Initialize the display by giving the global and patch variables initial values.8 |& E8 ~! k1 F8 @
;; Create num-cars of turtles if there are enough road patches for one turtle to
( e1 X o1 A e" [5 z;; be created per road patch. Set up the plots.
1 b, ]7 L4 O. V. I% N3 B$ ^% eto setup5 b d G- H. f- r! S% b! ~* ~! d
ca
! V8 H2 [( s$ y( n" y3 K setup-globals9 v7 ^$ o7 ^/ a& f( A* e |4 k
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;; First we ask the patches to draw themselves and set up a few variables# K2 }4 i G2 J* v/ ?. m8 N6 ]
setup-patches
- w$ t: h, q+ y* [ make-current one-of intersections
0 q% x+ l) N5 S8 S6 J' J label-current
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set-default-shape turtles "car") U8 V r; r% D L2 _) l
/ y, C8 D9 u( K& W# ^ if (num-cars > count roads)1 {: b, Y' J) x) P/ Y$ S5 \
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user-message (word "There are too many cars for the amount of "0 E5 v! @% R; Q3 z
"road. Either increase the amount of roads "0 E5 F5 u8 z5 u& v& j, _
"by increasing the GRID-SIZE-X or "
5 F! m4 f3 {! e6 P: X( d "GRID-SIZE-Y sliders, or decrease the ") D' y7 W1 [1 _4 _1 w& f* M
"number of cars by lowering the NUMBER slider.\n"9 W8 G+ E9 c) M& C! ^
"The setup has stopped.")5 k0 \+ t6 `9 \. r6 ~9 ?
stop
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3 N" n& ~& h6 e- { ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
& ~9 k6 j2 Z9 J$ ?% A crt num-cars0 v+ k, g* _5 N L1 m
[
9 a/ ~! s' F+ b; r# V! m( a setup-cars
8 ?. L% u# |+ [# N! f3 g$ |- M( ] set-car-color
7 ?/ }3 w% {& s3 W4 f8 n record-data
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* \9 V4 h. ?9 }8 @1 z$ e3 ~: J; z ;; give the turtles an initial speed4 k6 z; H. J* m- ]- q$ o3 T# I! V
ask turtles [ set-car-speed ]1 a; m, T, w6 I1 g6 m0 B+ Y2 l
( v8 d8 Y2 d9 E9 s6 U: G1 w reset-ticks7 x; W( E# w+ B+ f" ^: U: X: Y$ f
end* d8 E4 G0 n' u, g" i& ~' t5 r( [% Z
) Y" h4 @5 |' B! x0 ~& U7 H;; Initialize the global variables to appropriate values. o! N3 J8 f) [; V
to setup-globals
$ w$ A! X( e4 H set current-light nobody ;; just for now, since there are no lights yet1 X5 g8 J$ N6 x0 w) b
set phase 0' |3 f+ l. E [6 W r: B* M
set num-cars-stopped 0: S& B, K. Q* p* y
set grid-x-inc world-width / grid-size-x
0 {+ J3 E- g7 X 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 boundary0 @7 F# D7 E( Z- D
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
6 ]4 l& n" Y3 t2 Z; ] i( q;; and initialize the traffic lights to one setting
/ U. h q) a# z$ \0 |* Y% vto setup-patches
) v1 \6 X( m4 ^2 \+ y ;; initialize the patch-owned variables and color the patches to a base-color: K. ?1 b/ {# |+ ? m9 ~
ask patches2 N+ Z5 W5 K/ h! W8 H
[
0 o" G" L/ k' o$ j set intersection? false
& C; Q Z4 a0 M7 r set auto? false7 p5 p3 r, J1 H+ \) a/ z* K
set green-light-up? true
) \; |, W& ?7 m0 l1 B8 D+ y3 o set my-row -1
3 [( v+ n9 x/ r, b9 p' e2 \" N set my-column -1
5 ?3 k2 j5 V6 w set my-phase -18 T z2 k- d: C0 ]7 f+ [
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets; ?3 S( X: R5 C- Q, M4 l+ E
set roads patches with4 e# T6 c" @. z. h' k2 N) d4 h6 Q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! a. w) H+ }6 a (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& I5 d$ f6 G# q# d4 _- Y2 M
set intersections roads with
: t$ ^ o# N1 I [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
* _3 a: @' \ u7 B$ o+ H' |' ?3 j (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 F+ ?1 u" r5 R7 a3 j ~# B
4 V% [2 g! \# Z4 Z# n ask roads [ set pcolor white ]
8 o: ~; `( y: @9 B0 r- @ setup-intersections3 @3 @3 y5 L5 F3 |; |9 {1 D9 b7 M# G
end
, M$ Q9 K. q4 L+ S) a2 E其中定义道路的句子,如下所示,是什么意思啊?1 K. X( [3 \0 q( o+ L' I# d
set roads patches with' `) a6 u: f* J9 j
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or1 ]5 B9 [) H6 g) H0 A ]$ l* S
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# g; x) N( w$ H7 h! C' M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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