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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。8 J: O1 q7 ^: ~% B3 U; n
netlogo自带的social science--traffic grid这一例子当中,3 i' L. S. B2 N' L
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction: B- P4 Z% S) d" L
grid-y-inc ;; the amount of patches in between two roads in the y direction# u+ d9 a& d" N: U
acceleration ;; the constant that controls how much a car speeds up or slows down by if
. m: f9 z4 N, ]' P n/ g) V ;; it is to accelerate or decelerate% S( ?4 \5 k% E9 f; K
phase ;; keeps track of the phase8 [9 J8 O( n. R/ P/ P- e. n* A
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure; U: W, [5 V% z: W
current-light ;; the currently selected light
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5 N3 R3 u3 Z# j! Z( H ;; patch agentsets
! k- M) I- h7 Q intersections ;; agentset containing the patches that are intersections
1 ?% M' {- l7 F0 r$ y# L" P: |8 B roads ;; agentset containing the patches that are roads
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turtles-own' b# I6 O+ f1 ]3 |: f8 i/ C. m5 I
[
, T( h8 {/ s6 Z5 u, l( m- N speed ;; the speed of the turtle% a/ L L2 W3 E, v
up-car? ;; true if the turtle moves downwards and false if it moves to the right1 Y. @1 H [* t$ f# J
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
( {2 M1 y6 B3 l. m: ]% R green-light-up? ;; true if the green light is above the intersection. otherwise, false.
" b. ]4 a, D8 L2 S0 f ;; false for a non-intersection patches.
) P, E8 t5 h( T* M9 l6 L my-row ;; the row of the intersection counting from the upper left corner of the6 a2 H+ f7 Q6 {. w; j
;; world. -1 for non-intersection patches.0 [5 \ P4 O7 S1 E" m9 @9 C. Y
my-column ;; the column of the intersection counting from the upper left corner of the5 b* A. Z; d; N! V3 Y+ V
;; world. -1 for non-intersection patches.
! o5 C d6 G, Q. ^. P my-phase ;; the phase for the intersection. -1 for non-intersection patches.* P7 a6 F, C* M) b) }
auto? ;; whether or not this intersection will switch automatically.
9 W5 t+ j( P6 Z% O3 V ;; false for non-intersection patches.
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8 a- @+ q5 d# v;;;;;;;;;;;;;;;;;;;;;;
( c! {' _ @* o% C& f;; Setup Procedures ;;9 D2 Z7 a! k! Z8 X
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1 [. ~$ ^, j% L7 |6 j;; Initialize the display by giving the global and patch variables initial values.
* f* Q- j) ]+ i0 g5 x;; Create num-cars of turtles if there are enough road patches for one turtle to6 n4 o9 ~9 {/ P
;; be created per road patch. Set up the plots.
. |4 ]2 w4 |& A/ ]( ito setup
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! L9 c6 v4 k9 r {2 o setup-globals; Q- A1 s. C( j+ d2 \/ S2 W2 H
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;; First we ask the patches to draw themselves and set up a few variables% y' E3 x5 w N% \ }4 n
setup-patches0 J+ N* b8 z+ z' W, H7 ]) u
make-current one-of intersections' O+ L3 i2 H) E3 Y: \5 ]; K: w
label-current
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set-default-shape turtles "car"8 H" T$ Z2 P; f2 B* B
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
% ^7 a' Z. Q0 T l5 i "road. Either increase the amount of roads "
! ~) l$ R, E( D+ R) H' s# m5 G "by increasing the GRID-SIZE-X or " F+ s: m: P2 g% i( ]4 Z
"GRID-SIZE-Y sliders, or decrease the "2 K% ~ j% e$ {
"number of cars by lowering the NUMBER slider.\n": G# z1 I) N; ?; |8 A
"The setup has stopped.")
6 ^3 z! Q0 Z' X* n; x+ f stop
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9 B* z, [& q. X5 E ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
$ f9 z( U0 Z+ K- p0 x crt num-cars
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setup-cars
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record-data% M4 j8 z* J# b' Y1 U
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# _- ]1 f: Z8 _0 ]4 Y, B ;; give the turtles an initial speed
5 R1 y& \6 {9 R/ [$ a ask turtles [ set-car-speed ]1 |# G" {# ~5 Y& }. ?7 b
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reset-ticks
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;; Initialize the global variables to appropriate values
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2 J8 n3 e; }$ w; _# F# F- j( U( W7 c set current-light nobody ;; just for now, since there are no lights yet
$ E$ w% S, q! @ set phase 01 ^/ k( k8 Z4 F6 D
set num-cars-stopped 0
5 d/ h1 ~6 J0 a1 c o set grid-x-inc world-width / grid-size-x* V6 |1 s9 e8 G) G# f+ u% s( N% j
set grid-y-inc world-height / grid-size-y- }+ K5 l1 M$ [6 {1 E( H
) U' j `3 x- b* x r5 a ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary0 h9 ?" [& @9 z5 f
set acceleration 0.099
6 a3 U) C% M: e8 ?+ eend! ]- f! [6 x- v
& [* |7 J. C" O& D;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
$ y. L+ Y z3 n;; and initialize the traffic lights to one setting T4 ?7 E8 j* X. {( V
to setup-patches4 F! Z2 L( l X# {1 I2 o
;; initialize the patch-owned variables and color the patches to a base-color
' E5 E) }2 p1 A% X" K ask patches
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set intersection? false T- {9 h' e# [
set auto? false
7 Y+ H: N6 M0 r' C$ F0 W set green-light-up? true6 j" u# d, A9 ~3 f' V
set my-row -19 Y+ P2 c) l! N% L& G% t& |7 {
set my-column -1: E \' [2 E, Y4 l U
set my-phase -1
) _. }( o: x) N' h5 ^ set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets0 j! ^8 P9 l# B
set roads patches with# U% ?$ h# M7 t! g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 M4 ~( V' {$ l9 ] (floor((pycor + max-pycor) mod grid-y-inc) = 0)]- O# W1 l5 I% g* M% B4 ?! R
set intersections roads with
j0 D6 s- u& r7 c4 [- \ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and! k6 l4 Z& ]' D: v) A Q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ j! ~. Z6 ?/ u3 v- J+ I' h \
3 F- `# G# V4 ?; p d ask roads [ set pcolor white ]+ }/ K+ \1 `( P C; W
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?* W- {4 M# b0 U4 j4 p: I7 Y
set roads patches with
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# J0 |/ Z3 x- x7 }6 m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ w; e' m# a; Y2 u) f0 d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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