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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。* I2 M0 O# W! B a% v5 p
netlogo自带的social science--traffic grid这一例子当中,
- O2 `, x& o8 Y9 g' ]globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
- L# e g" l% D# y! E3 K0 \5 A grid-y-inc ;; the amount of patches in between two roads in the y direction
' b$ b G( @( [! G9 w5 A acceleration ;; the constant that controls how much a car speeds up or slows down by if
3 Z5 I6 {8 v1 A" \5 y ;; it is to accelerate or decelerate- U7 M V; t/ W
phase ;; keeps track of the phase
: Q; a* ^4 E# g* C$ m. ? a num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
. ^' N3 R. i( d y8 K( D current-light ;; the currently selected light5 r' f) w) v2 F. s2 b" X. |
* Z# s) ~# T! b0 o ;; patch agentsets
) E+ o, Y6 U( S8 v/ V% n intersections ;; agentset containing the patches that are intersections
3 E2 W8 W/ Y) U' C8 j0 F# b) \ roads ;; agentset containing the patches that are roads+ l1 |* G6 d4 l2 F0 D! g# F
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8 Q% ]$ g+ H8 t3 O& F% c5 iturtles-own
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speed ;; the speed of the turtle
1 j* {' _; N4 V' x% \3 e! i+ k up-car? ;; true if the turtle moves downwards and false if it moves to the right" V4 ~0 [/ g! u+ y8 S6 z& k
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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% H9 a% M5 a2 f6 ]! Z% ?! [% O intersection? ;; true if the patch is at the intersection of two roads! G+ i+ y* g% r3 J+ m
green-light-up? ;; true if the green light is above the intersection. otherwise, false./ Y( P4 W( N; D" ] h3 Q2 u, U6 n1 o
;; false for a non-intersection patches.
3 B" [! i6 L9 n" ] my-row ;; the row of the intersection counting from the upper left corner of the
9 {( R/ C* j; U/ ~- F1 T ;; world. -1 for non-intersection patches.
0 H# x+ U6 p- u7 Y6 L1 ] my-column ;; the column of the intersection counting from the upper left corner of the: Z6 H/ o. @9 E; j: O6 h3 @* ?
;; world. -1 for non-intersection patches.
9 k* ]! S- D/ i6 V4 V my-phase ;; the phase for the intersection. -1 for non-intersection patches.( f4 b" M `% P# `8 C7 ]3 U1 s
auto? ;; whether or not this intersection will switch automatically.2 Z0 z C& T% R" K' |
;; false for non-intersection patches.- d7 ?6 p# K, }0 \1 v
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( @& {3 `+ ~$ d3 N o;;;;;;;;;;;;;;;;;;;;;;3 Z8 P: `# y9 Z x1 B6 |$ R( h
;; Setup Procedures ;;% {: h8 f" w3 @+ Y9 ^" ^
;;;;;;;;;;;;;;;;;;;;;;- A" Q( b4 f4 k4 E+ O8 R
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;; Initialize the display by giving the global and patch variables initial values.
; Y5 O" h, d; r$ B;; Create num-cars of turtles if there are enough road patches for one turtle to) Y+ b" Z, ?; ~$ N4 B/ w Z _* ?1 \
;; be created per road patch. Set up the plots.7 E9 d5 |5 t+ A J& S/ M
to setup( U1 d& F! M0 R, W
ca
( }7 R' K+ a, k( B! k. j- _ [- y setup-globals
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$ k( X e1 S; C$ B$ t ;; First we ask the patches to draw themselves and set up a few variables! r# _2 j+ X/ [5 n6 I: j6 t* ?
setup-patches n S* k) E9 W/ A, b
make-current one-of intersections
- h2 g p0 w- c" A! ^& r label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)
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' E6 E( f! R9 i7 f& U& @ `8 a+ }1 d user-message (word "There are too many cars for the amount of "
, Y( v. c& j( b% k2 Q* { "road. Either increase the amount of roads "; O9 n9 h. v7 m' j' X
"by increasing the GRID-SIZE-X or "
, Y$ K2 p, P' O5 s "GRID-SIZE-Y sliders, or decrease the "- v( z7 q) |0 q3 C
"number of cars by lowering the NUMBER slider.\n"
) Q- C# m: R6 H7 R- Y "The setup has stopped.")
% k, M( g5 [# x I p% `1 B stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color! E J- T1 e0 a3 M# C# m1 T+ w
crt num-cars" W" S- v) b$ F# i$ w
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- y0 ]4 B3 Q }3 W$ [' n setup-cars r& Z; V: b( D2 ]) N6 ^
set-car-color
0 [+ I+ o2 P. ^9 ^3 O record-data
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" t4 J5 G0 M u& ^( t# g ;; give the turtles an initial speed
% ]8 L8 D: j* G4 f# G# R8 C ask turtles [ set-car-speed ]
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reset-ticks! V* w( y- ~0 G. ?
end5 z% j% ?0 [/ @ Y! e
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;; Initialize the global variables to appropriate values+ [; c" N) a7 h4 l1 k L- ^; n
to setup-globals
, s5 X4 M5 \2 Z+ _# h8 w9 {. N set current-light nobody ;; just for now, since there are no lights yet( U7 B1 A" A9 A& g8 V
set phase 04 T) b. _7 i7 P* {+ m3 a
set num-cars-stopped 0
$ } t! W0 {& G5 [- F, N- c set grid-x-inc world-width / grid-size-x% T. o- I! {7 I. }/ l/ b7 K
set grid-y-inc world-height / grid-size-y
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3 I% o& @- i' \/ V: r P ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary' b1 y( S6 i2 S
set acceleration 0.099/ S2 q! J, Q6 H- e9 j3 z( v8 K5 [
end6 ~* f; c# H# t) t: [
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,% Q7 F Y9 i+ v) `
;; and initialize the traffic lights to one setting3 f0 @9 F! C4 J5 ?" j0 ~; [
to setup-patches
, F/ B! b- P$ W$ P. z ;; initialize the patch-owned variables and color the patches to a base-color
" B1 L4 q. B) i ask patches% k) `2 ^/ G5 G$ s* ~6 h
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4 |( J' E% [* x& K! R& [5 \7 {3 Q set intersection? false. F, [$ j8 Q! l3 P. r3 u
set auto? false4 k6 L% d1 \4 Y+ k$ G
set green-light-up? true
/ M. Y% Q6 x* ^2 Q. _ set my-row -19 v( _8 a/ g7 c3 L* j0 B
set my-column -1& L( }- Q2 I5 d- u
set my-phase -1
( J* T0 u( b/ w1 X/ f$ N+ p+ s set pcolor brown + 31 L7 y5 r. Q( s" \# z& ]
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& H W, |" A& H$ l& y ;; initialize the global variables that hold patch agentsets
; y. Q1 j) s- f1 y2 U3 i, _ set roads patches with! w+ j$ v1 Q0 z! s8 y/ b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! y, s5 X" ? } t( R+ d( F (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 q* y7 ]- \* v( |0 v set intersections roads with7 Y( K6 y/ j. z$ p- I
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
; w! l& c# W2 n1 g (floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 x/ e" }; l( l
1 t8 C+ W; w6 \4 W ask roads [ set pcolor white ]9 c% ~! X7 n- v l/ ?& B
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 G8 \ Z9 |( a8 H @) e1 _ set roads patches with. X) E" D' V: [/ w3 W& P
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, P* F5 f7 o4 G- E* d
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! D$ N, G$ L) e2 r. X ^3 n+ }
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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