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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。4 p* l/ \9 Y: ?
netlogo自带的social science--traffic grid这一例子当中,1 m9 ], F9 k& C* j' b2 G# Y X
globals: R) r; v* @0 I0 n# X
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% h' c( W: [, i grid-x-inc ;; the amount of patches in between two roads in the x direction" Z& c/ c: S4 \* u) { w
grid-y-inc ;; the amount of patches in between two roads in the y direction
7 K5 h# [' x/ S* k9 d acceleration ;; the constant that controls how much a car speeds up or slows down by if
; W, `6 B) I5 f) I$ p ;; it is to accelerate or decelerate
2 Q( U y* G# N7 M9 A phase ;; keeps track of the phase1 {/ A# T$ @0 W# D5 F4 G9 y
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure. ?4 C0 @+ F7 ~5 L2 p
current-light ;; the currently selected light' y m/ Z- s7 d t& V- R
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;; patch agentsets
: C) w8 K' [4 ^2 I7 z" P intersections ;; agentset containing the patches that are intersections
4 c0 W+ O) e' J, s roads ;; agentset containing the patches that are roads
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turtles-own
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& k* }" t m. R3 V6 K& K# H) x& y speed ;; the speed of the turtle3 C' V! n/ e- V+ @* M
up-car? ;; true if the turtle moves downwards and false if it moves to the right
4 }0 z) `4 g2 z2 g wait-time ;; the amount of time since the last time a turtle has moved# l4 Q2 t1 Y k" D% C; R7 {5 j8 T) b% V
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
* a: I9 ~. i }2 E; m- I a; J green-light-up? ;; true if the green light is above the intersection. otherwise, false.
6 M2 j' d( y! ~, a ;; false for a non-intersection patches.# H4 C; B1 I: H9 H2 }1 x
my-row ;; the row of the intersection counting from the upper left corner of the% T1 c' i; e5 v' N. _! K$ E1 T+ s, G
;; world. -1 for non-intersection patches.
( L" e- W, q- S my-column ;; the column of the intersection counting from the upper left corner of the
* ]8 K6 l) ]/ N! f ;; world. -1 for non-intersection patches.
& d% p& P/ Z& b2 _8 d my-phase ;; the phase for the intersection. -1 for non-intersection patches.
% ~( k- ]" {- w9 c auto? ;; whether or not this intersection will switch automatically.; B3 ]7 v. `) Q+ a* ?
;; false for non-intersection patches.
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, ~5 m; Z7 q: G+ ~; J+ s;;;;;;;;;;;;;;;;;;;;;;9 p3 H% C# N2 ]. H
;; Setup Procedures ;;
$ V. D+ w1 q7 Q# C) D;;;;;;;;;;;;;;;;;;;;;;9 X. y$ A. |) A
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;; Initialize the display by giving the global and patch variables initial values.$ |0 n1 a. x- w2 S( g0 m8 l- Y/ G
;; Create num-cars of turtles if there are enough road patches for one turtle to
7 z, y6 E* U& y- z; c% h Y;; be created per road patch. Set up the plots.
) `7 t9 i$ c/ k- L, C7 g, _; x! Eto setup9 X( ^% s8 B* L+ U: v
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setup-globals4 K" H6 @) E0 E7 j& P" Z
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;; First we ask the patches to draw themselves and set up a few variables
# |; A. Z1 ? ? setup-patches
. c4 y- D3 [+ d* V0 R make-current one-of intersections9 p/ X+ O6 m0 ?" L* x1 ~
label-current
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. k0 M6 Q+ R. U ?0 u6 L5 u set-default-shape turtles "car"
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1 J9 G. B# K* E1 U2 d5 c' | if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of ": ?0 h0 p! l! Z
"road. Either increase the amount of roads "
- h& Z- O: U. n& e' W! h% c5 R: K# Q6 D "by increasing the GRID-SIZE-X or "4 N& b) u+ t D6 }$ y# q" d- Y
"GRID-SIZE-Y sliders, or decrease the "7 b8 p) q! g' H! e" `6 x
"number of cars by lowering the NUMBER slider.\n"
0 y0 b: X+ t4 Z0 S0 b "The setup has stopped.")1 P1 ]- b: X- ?# |4 M
stop" r" t5 m4 |6 z8 A9 n% f# Y
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color- ~' u$ m' i# V7 _; V1 W' Z
crt num-cars! m, C$ M# A( t$ H, S _) C
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- l7 @0 `7 y# _, c% f setup-cars
" Z, f8 i& ]& }9 o3 ?, J% s set-car-color1 Z/ k5 Q9 L' [- N. o* `4 K4 m
record-data
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;; give the turtles an initial speed- H; z) Z& N5 l) E5 ~( j4 U
ask turtles [ set-car-speed ]( i# T! @1 z; S8 f5 S8 I# ]
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reset-ticks
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s+ N6 N% [3 ?( M: v2 k. B' f;; Initialize the global variables to appropriate values/ T3 Y7 e! w5 H3 x
to setup-globals
+ n! n) f g- r set current-light nobody ;; just for now, since there are no lights yet
( ]1 ^2 L0 W' y7 D3 L( ~ set phase 03 H* ? Y/ G6 B- V4 J' ~# q
set num-cars-stopped 0
) |9 [ R- x7 S3 j' W, ]; _9 I+ g set grid-x-inc world-width / grid-size-x- ]( ?5 I5 c$ W% X; L- z
set grid-y-inc world-height / grid-size-y3 D- m. q: q+ z
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
. Z- \' S. B: V8 g- ~2 P. p set acceleration 0.099& p" E Y: Y6 t; X2 v
end( j2 n. W# f9 [
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
9 o: T: g; s9 \;; and initialize the traffic lights to one setting; J2 d9 K7 z6 r4 o7 Y7 N8 Q& V7 W
to setup-patches' G. g) K3 N% O; g
;; initialize the patch-owned variables and color the patches to a base-color
- R0 D& A# T- Z5 k- f ask patches5 u& y/ \ F7 U, |+ w
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set intersection? false8 i7 V% z" X4 U1 d7 W
set auto? false
3 Q, F- b" b& d set green-light-up? true1 ~" y3 I& j5 |
set my-row -17 i8 h, c3 L3 l" q# F0 Y
set my-column -1# p- W1 z! S' v3 A
set my-phase -16 T5 V, V0 g( C3 K. |
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets: g n8 V; |) k. G0 [
set roads patches with# [1 E( Q' _& G& i: x! X
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 p1 j' K4 S& o% i; s (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 t1 F/ C2 `" o, t" Z% ]# z) {! c set intersections roads with- C9 K% ~; n3 K& N! f" ]+ m3 U
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
1 D5 A" u) l. N: H (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
! |- \" u6 s; C: V+ S) R0 |: J, V setup-intersections6 k/ L% [1 Y/ J3 p# @
end, m( m3 j/ s q n* L0 A& g! ^
其中定义道路的句子,如下所示,是什么意思啊?
0 x4 K7 h3 ~! V: ? set roads patches with) Z! A9 x r. q$ f
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* i& i& _1 V o4 W% N2 [9 C( y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 x6 U/ _$ K% s1 m5 o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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