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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。
5 ]1 u1 R/ _; Z: B/ Qnetlogo自带的social science--traffic grid这一例子当中,
/ q5 x+ V( B9 r% E3 m; `- Yglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
" ?5 y. J; J [+ B grid-y-inc ;; the amount of patches in between two roads in the y direction% q7 a5 H( J1 ?! o( ]" l1 k
acceleration ;; the constant that controls how much a car speeds up or slows down by if
+ k% I! W; l. V" E# z ;; it is to accelerate or decelerate
- q3 `! m" m" O3 Y+ X phase ;; keeps track of the phase& o/ `* I" {: X$ p+ p- x
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
8 r* V' Q5 l" V. G* f9 _4 k current-light ;; the currently selected light
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/ w, }% P7 G, l, i) ]- ]/ O9 V* x ;; patch agentsets
9 J- w: F7 }, N8 n7 n, @ intersections ;; agentset containing the patches that are intersections
" @ s$ n9 G" K F; m* | roads ;; agentset containing the patches that are roads8 Q! M/ V. L9 c* r6 e7 t
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turtles-own) o/ J9 B) b- D5 U' {
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+ o$ ~; Z1 a& E W8 {: S [ speed ;; the speed of the turtle/ ~( e# |/ [' l4 \( z! @
up-car? ;; true if the turtle moves downwards and false if it moves to the right% v, J3 b5 i+ }2 b
wait-time ;; the amount of time since the last time a turtle has moved [' m& y/ ]% G, t
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patches-own
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3 e) H1 |4 K3 Z" N, O+ Y1 K1 ?: O1 x intersection? ;; true if the patch is at the intersection of two roads% i7 Q7 m5 o' [2 n3 L8 o, D4 z+ u
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
1 A! i% D$ W( z1 |1 s ;; false for a non-intersection patches.
' H$ o( ^9 K5 g& r7 E my-row ;; the row of the intersection counting from the upper left corner of the9 ^- @% u/ ?. o$ c2 o+ g" E
;; world. -1 for non-intersection patches.
$ {) X9 |' n2 w* B5 J# I my-column ;; the column of the intersection counting from the upper left corner of the! F5 S* n, g* V; U+ w
;; world. -1 for non-intersection patches.
. w: X. n$ H3 r- U& y; L8 G% K my-phase ;; the phase for the intersection. -1 for non-intersection patches.
; t6 M4 W& C0 N auto? ;; whether or not this intersection will switch automatically.+ y# |) B8 M" o! y) u4 L' e
;; false for non-intersection patches. {9 w" `; q9 l
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2 y# y2 D* U: g: r" {+ j! {& G;;;;;;;;;;;;;;;;;;;;;;/ P3 ?0 c e$ m) ^
;; Setup Procedures ;;" o. [# G' ]5 ` b, J
;;;;;;;;;;;;;;;;;;;;;;6 q k C. g$ Z9 z! e" X
) e8 ~( ], C( k, p; H: T9 R;; Initialize the display by giving the global and patch variables initial values.
) g1 |. D8 _( o2 x: w$ {5 Q;; Create num-cars of turtles if there are enough road patches for one turtle to
$ @, C" } `! G( g% K% P3 X8 R5 h;; be created per road patch. Set up the plots.5 g5 {3 J, G- O" g
to setup
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setup-globals
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1 o" A) x# Y5 r: c ;; First we ask the patches to draw themselves and set up a few variables( v/ }' a* W$ N4 x( F4 h* }+ H) @( |
setup-patches ~8 O5 p! W" K& M* W" U& H2 E
make-current one-of intersections
5 F0 c. Y& J& Z/ ~ label-current3 v3 B Y2 M8 }+ M( i
/ T. K* E' B8 `1 @: R set-default-shape turtles "car"
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if (num-cars > count roads)
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8 g- M1 l% R5 C! k$ m8 `5 E9 _ user-message (word "There are too many cars for the amount of "+ w6 p- } W) J0 S: {
"road. Either increase the amount of roads "" Y. D* Q+ {& U5 F& u
"by increasing the GRID-SIZE-X or "
0 `& j0 \4 e# O }# i; N8 B "GRID-SIZE-Y sliders, or decrease the "
- q7 V# l6 i" a6 e "number of cars by lowering the NUMBER slider.\n"
& w2 g& y) z. _3 v "The setup has stopped."); Q, d7 a+ Y8 ^$ y
stop
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' u% v* k+ Z5 |3 P8 m* j' [ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color+ d2 i0 d C* f) A; {
crt num-cars
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setup-cars
& @" K) I' C" I3 j$ z8 r9 _ set-car-color- ?0 ~8 G1 c( U, V
record-data% a6 w# g7 w: |! ~7 U2 S7 ?
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;; give the turtles an initial speed
W ~9 t" j( n+ x' U) } ask turtles [ set-car-speed ]
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9 r# w( F0 K4 r V7 A( s reset-ticks6 g; K/ q+ ^/ X' O& U3 ]1 c; ^
end
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;; Initialize the global variables to appropriate values4 i) p' R3 F6 c- L
to setup-globals: |( I; H7 e' o3 S
set current-light nobody ;; just for now, since there are no lights yet
t0 G! P/ P5 Z( f9 k0 } set phase 0
1 R' i' _2 ~) d. M4 ^; }& B5 w3 p/ z set num-cars-stopped 0
1 A9 M) }7 u( }- ^ W; A& j0 C: [& i set grid-x-inc world-width / grid-size-x
3 F* o! w, U9 }) F; `: ?) {3 L! N set grid-y-inc world-height / grid-size-y
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; K3 m, F m( z( l ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary( P8 u9 F; u$ k. q8 Y! K
set acceleration 0.0996 r! I. F/ y0 K/ v& n6 }: M
end# _/ q3 Z& y* V2 C0 a
: j2 D7 ?4 F/ y( R9 ^;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 x) V, k. D( L% ]2 W5 k;; and initialize the traffic lights to one setting% _, o) ?7 |0 @+ `: X
to setup-patches
% x1 X4 N+ R9 t ;; initialize the patch-owned variables and color the patches to a base-color& o$ \6 N# S# v
ask patches5 ~- B4 K; O/ K* e1 @
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1 E7 @' N- S2 ?$ K2 |8 q set intersection? false
- Y7 J9 R0 }/ J i set auto? false
# d& k% E% ?/ ~* g! Y# O& V* V set green-light-up? true4 \* J: L3 U/ P( L# B& d6 F
set my-row -1
. s4 b5 |4 r! J set my-column -19 u) e& U$ v5 R
set my-phase -1
6 X2 v/ o# `! T! m, ~ set pcolor brown + 3
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3 {7 r$ X% m4 I b$ p ;; initialize the global variables that hold patch agentsets
: h5 L, g. q9 ]3 I set roads patches with3 N$ U1 K6 x0 q. U: \; k/ V( ?1 O- S
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; H! ^6 g$ y) P& g, o (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: f% L/ M$ \' `# T. O set intersections roads with) P6 [3 ?+ e0 V a+ G5 K5 c
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and5 |6 G3 h4 ~" V
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 ~; ` o; Z, N8 \- ~
, j% Y: C6 M; w; h3 K9 o ask roads [ set pcolor white ] F3 a2 E/ f0 \ Y
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?) {) {6 p) r) d( G/ f! t. B% ~
set roads patches with: r. c9 P8 ^5 ?( q, F3 Q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 Y% L5 b5 H* s- B& _ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, z' |, f8 o' M8 t& [* B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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