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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。; N/ U( ?# Z& s( L5 W7 T
netlogo自带的social science--traffic grid这一例子当中,
8 S( ]) x9 [. ~8 R" v1 Qglobals2 [1 u' Z( y: a! W& \& a) f
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grid-x-inc ;; the amount of patches in between two roads in the x direction3 c3 q4 d$ ^# Z: N: O9 p
grid-y-inc ;; the amount of patches in between two roads in the y direction1 u2 m; L1 u8 H- K4 z
acceleration ;; the constant that controls how much a car speeds up or slows down by if
( C. P$ }1 W& L H ;; it is to accelerate or decelerate
1 _7 v, v; M/ e1 a+ ?9 C6 A phase ;; keeps track of the phase6 z, O) V G/ n; T6 r- y$ u5 S
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure5 G1 e7 y8 z0 \* z( [ c
current-light ;; the currently selected light; k3 ^) K4 c1 C4 A& ~( x9 s. r
) b, d" H8 i x$ J0 N- m ;; patch agentsets- l7 r4 {* d$ I5 E% D
intersections ;; agentset containing the patches that are intersections7 q/ n2 h9 R& a1 U; G
roads ;; agentset containing the patches that are roads
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turtles-own$ l% l8 g2 Z4 t- H. u, x
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% a0 O1 m/ G+ _7 j7 } speed ;; the speed of the turtle; f7 L% D% K2 x- @6 z
up-car? ;; true if the turtle moves downwards and false if it moves to the right* g$ C9 W1 E/ D+ [' \5 y1 {: L O
wait-time ;; the amount of time since the last time a turtle has moved
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5 I: @% e7 b! ] K1 u- dpatches-own6 R" _( O+ e: H
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% R, s& s9 o' u c; g$ }) @3 d intersection? ;; true if the patch is at the intersection of two roads
- j! I9 B" s N5 n- d1 k green-light-up? ;; true if the green light is above the intersection. otherwise, false.
1 |+ H; g6 _" T, T8 f# u& | ;; false for a non-intersection patches. k I: X) t1 [
my-row ;; the row of the intersection counting from the upper left corner of the. x( w5 r, {: U% W
;; world. -1 for non-intersection patches.
. ^, w3 _6 d1 K. k5 L0 g7 f my-column ;; the column of the intersection counting from the upper left corner of the
3 _7 ~! A* N2 A; h. P4 U ;; world. -1 for non-intersection patches.
0 _8 V5 H0 m! f my-phase ;; the phase for the intersection. -1 for non-intersection patches.# \- _: {% e, n# Z/ k
auto? ;; whether or not this intersection will switch automatically., V3 G1 p7 T( L9 y7 |1 Q3 B
;; false for non-intersection patches.; [# f" M' p L' ?
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;;;;;;;;;;;;;;;;;;;;;;* |; a1 U; Q9 `$ y
;; Setup Procedures ;;
* o# b C0 Q0 A7 {;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
; w. ^2 ?( m. q;; Create num-cars of turtles if there are enough road patches for one turtle to
# {1 I% T8 z1 h" C. h; s;; be created per road patch. Set up the plots.
7 @3 i3 s+ k4 S2 O$ r( f% Qto setup* Y& C: v( O4 f1 X* |. p3 k2 i! Q
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables) L& l' T) N- @3 E" U
setup-patches' T9 f8 _8 Z, @
make-current one-of intersections! k% q2 l1 m. y
label-current
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set-default-shape turtles "car"5 }' N) p O4 @4 g' ]( v- H
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if (num-cars > count roads); A# }$ @. R& }* v
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( S& F' m9 K$ O: G% } user-message (word "There are too many cars for the amount of "
$ p+ E) s+ J1 r7 _( i8 m "road. Either increase the amount of roads "
6 F, r: {) g5 k1 N) d "by increasing the GRID-SIZE-X or "
. @) a" R* j, n! N4 f "GRID-SIZE-Y sliders, or decrease the "6 m0 d2 O+ _0 p% L$ A! d. v! G
"number of cars by lowering the NUMBER slider.\n"- M4 o* X; t0 @9 W
"The setup has stopped.")6 p$ h. ~4 ^( U
stop
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3 t$ `% B5 @: `; | ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
& L$ ]# T" \8 \! p" F5 n9 i crt num-cars% Z+ `/ f- a7 n" U E0 q+ F) I
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setup-cars
/ ^8 B2 h! h7 {, |/ f$ H set-car-color6 `/ k6 l; i& T; f5 P
record-data
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;; give the turtles an initial speed
0 I3 B2 C6 p8 |- L$ f5 h" R ask turtles [ set-car-speed ]
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reset-ticks
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/ w. |$ G4 K8 c. }6 K* E* P6 C( L% n;; Initialize the global variables to appropriate values( y8 v9 h, D5 Z" K( y- V( }
to setup-globals) \4 M( T" ~* A4 [& g) ?- y! E
set current-light nobody ;; just for now, since there are no lights yet
0 q" u# B1 ^" a: _& Y! q; d set phase 0
2 m: G0 d! V2 s6 w6 E% G3 k set num-cars-stopped 02 Q( c4 a7 b4 x8 H( G! Q4 V. m+ e
set grid-x-inc world-width / grid-size-x
0 K) e! o( y" i 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
! c, f( j% q8 F! [. l7 E set acceleration 0.0993 U$ D4 Y4 } x! l0 ~$ v' Y E$ g
end- V- a8 _/ t9 h. a/ g9 O3 q3 u8 F
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,, |, E# b- D6 C/ ^2 U/ M
;; and initialize the traffic lights to one setting# w8 N" u, p n6 ?+ w
to setup-patches
/ b2 s1 O. n4 n3 N ;; initialize the patch-owned variables and color the patches to a base-color+ M I3 ^% X$ E. Z3 {; x3 H* _
ask patches. T$ o+ d* i2 k; R
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7 m3 r0 A) `. V( z set intersection? false
3 G( M. L2 b9 ~1 \1 W set auto? false' ~; j# _# ]% h, K
set green-light-up? true) P: q* X1 @/ E) I
set my-row -1 E. M( |9 b" L7 ?2 I9 V
set my-column -11 H! @! [+ q6 S, g7 f
set my-phase -1
- W6 ^/ D; }5 ~& y- {- f set pcolor brown + 34 \0 G, w9 L. _$ f2 ?
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" a$ H& R! Z7 ~8 d- P ;; initialize the global variables that hold patch agentsets
* b p# Y4 q+ n; ^3 ^, p0 K set roads patches with1 h; Y- _. [- \: N- }* e3 g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ w" D: l9 [* v& ~ x
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- L4 C) ]7 i( ]4 v: Z$ ^. } set intersections roads with3 c& u/ F/ ~+ v" A* H ]% g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and1 T+ k# h$ ^2 [/ V0 F. z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 }2 U( [4 m7 t* R# G" |
* B0 i# g9 a$ S y9 b6 p& w ask roads [ set pcolor white ] @( l# h9 c1 J/ i7 o W5 q
setup-intersections
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" @* O& t. b) G, }( B: j其中定义道路的句子,如下所示,是什么意思啊?( q" v/ ~: `5 m- r
set roads patches with
$ I* `& W# S/ s& ]: f8 n+ R! y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, k1 y4 Q& y7 f (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ N0 t$ f+ i1 }+ [, J' @* i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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