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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。6 m8 L4 @! B# p* |* p: K8 I' L6 e
netlogo自带的social science--traffic grid这一例子当中,
1 O9 c$ n+ `+ W+ B1 v% gglobals
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1 l9 t2 O1 B' {- w( L4 q; n grid-x-inc ;; the amount of patches in between two roads in the x direction
: w( V- ~/ q1 r1 \( s7 c grid-y-inc ;; the amount of patches in between two roads in the y direction
7 w: i* e* m% G+ O' R ? acceleration ;; the constant that controls how much a car speeds up or slows down by if
* \! E- ]" z9 M/ \& e4 u ;; it is to accelerate or decelerate
! Q0 R" l" r* H* N$ H: \ phase ;; keeps track of the phase, A0 i7 H- _; k' _( b2 v
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
3 b8 o/ t. J/ s7 N5 x* [ ]$ z current-light ;; the currently selected light
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) u; w5 q! y: G ;; patch agentsets
! [* V" B, y% U9 k% A: @ intersections ;; agentset containing the patches that are intersections1 a0 n% e* d7 Q9 a$ Z% W: j% ?
roads ;; agentset containing the patches that are roads
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# ? |) z- ^ V+ g# T! t% w; f# Vturtles-own. I" s3 B0 D" q0 ~$ _
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speed ;; the speed of the turtle
: `# _* ]( I' t. X. W( x" [# B up-car? ;; true if the turtle moves downwards and false if it moves to the right
" g3 c. e( c3 s5 z wait-time ;; the amount of time since the last time a turtle has moved
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0 y1 ]- A0 [) T$ kpatches-own
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7 L. ^* H: u3 {& W# o4 X intersection? ;; true if the patch is at the intersection of two roads
0 M$ c+ j4 \1 k% u8 a green-light-up? ;; true if the green light is above the intersection. otherwise, false.! l3 H+ j* s! ~; a& G* I5 y
;; false for a non-intersection patches.
2 n- ]8 \, X: n d6 r- G# x) ~ my-row ;; the row of the intersection counting from the upper left corner of the
: a$ M: r, B8 ]# ] ;; world. -1 for non-intersection patches.
, F! w4 ]% h# u8 i my-column ;; the column of the intersection counting from the upper left corner of the! l3 N- c% l& m* B( i% a8 h
;; world. -1 for non-intersection patches.
& X* u+ e' y( a+ f8 ?! V0 O" z; r my-phase ;; the phase for the intersection. -1 for non-intersection patches.2 ^( N! v- C2 G% Q/ t3 d
auto? ;; whether or not this intersection will switch automatically.4 ^# r2 i3 x0 S. K4 M) b
;; false for non-intersection patches.; v' b" g' R! m7 W! O) ?
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7 R) s* n8 i; J. \; |;;;;;;;;;;;;;;;;;;;;;;# _. R6 n- Q. O! l/ y5 O
;; Setup Procedures ;;
$ ~3 L4 r6 \* {& O3 k$ }8 ^ q+ x;;;;;;;;;;;;;;;;;;;;;;
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% ? c, U. ~" ?# e. T: t9 Y% g;; Initialize the display by giving the global and patch variables initial values.6 A! D/ q' `/ p: n
;; Create num-cars of turtles if there are enough road patches for one turtle to5 G9 \7 o4 T6 ~, \+ v% z
;; be created per road patch. Set up the plots.+ P; f; G7 _) |$ m4 v$ U
to setup
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! t& C- ^: t! E- s6 y setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
0 L. r; J- c& L0 C: G: b- N setup-patches5 V! G- m. b3 y* \2 r4 [: h- X
make-current one-of intersections2 M' P# @; g. ~, ^
label-current1 j" c1 r' k# f. G1 |- K
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set-default-shape turtles "car"
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if (num-cars > count roads)
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. r# u% x* r V3 K3 x( c user-message (word "There are too many cars for the amount of "
" P" h, r( q5 }+ O "road. Either increase the amount of roads "4 Q6 `: b$ C: i' I$ n
"by increasing the GRID-SIZE-X or "
" p m+ I* B9 w" o8 P: P! S "GRID-SIZE-Y sliders, or decrease the "
; h6 p. w) ], O1 K5 N "number of cars by lowering the NUMBER slider.\n"2 v& x% Y# h0 N( a
"The setup has stopped.")
, Y3 }# ^- \; V# e0 U stop. A# d u3 i* [
]
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color$ M1 f: }& E4 c" s: v
crt num-cars
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9 _# B' M i( w) d* L- I setup-cars
2 m' z' F5 v- w; p( j set-car-color
7 f5 ^+ r d. i4 `2 U- M* _ record-data
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;; give the turtles an initial speed
( O# ]! W7 M @2 } ask turtles [ set-car-speed ]3 N. H1 U9 p8 L e8 E
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reset-ticks
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;; Initialize the global variables to appropriate values1 A+ z J1 X! _5 Q( q
to setup-globals
' L$ m& \5 t' ] set current-light nobody ;; just for now, since there are no lights yet; A; _- @# ~/ L; F1 A( f
set phase 0
" @6 s4 n' t# b( T' h0 _/ ^- c) d set num-cars-stopped 04 N, s/ n# R) z k
set grid-x-inc world-width / grid-size-x
9 c; [/ e E3 U) }9 y set grid-y-inc world-height / grid-size-y% e% t8 P- ~0 o7 I4 g
, `* W5 N) O1 U; X& y$ ] ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary4 N5 l$ ?+ b, l3 h0 x5 d
set acceleration 0.099
! S/ G6 @) o5 Iend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
$ R. O) u# y9 S0 O" c; h+ z;; and initialize the traffic lights to one setting. ]/ }/ Q9 Q3 s, f/ k. Q9 r
to setup-patches
9 |8 F* @" G3 e& ?! ^9 }( t ;; initialize the patch-owned variables and color the patches to a base-color
- ~) J7 {! O) q% y" {* A ask patches1 u. b/ Y1 q, E# I' m
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set intersection? false( ?5 J+ G4 g+ K2 q
set auto? false* F; F! g% B. {
set green-light-up? true' R; w3 }0 R: F- i9 N* }
set my-row -1- r. }2 U( [8 A& A1 D" j
set my-column -1
( Q' Y! d$ }0 A5 m set my-phase -1
4 @7 |8 h5 Y3 p. X9 q3 D set pcolor brown + 3+ `$ b4 H5 I+ O! b$ y
]
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;; initialize the global variables that hold patch agentsets
3 p" }' ?3 S( M! \- A' t! K set roads patches with
( X: h8 l0 D, _3 e [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ a. p8 X7 t3 [* Y4 [0 \
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& V; y" ` O) Q- T3 p- X set intersections roads with5 I3 }- n9 @& h- |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
( g8 Z+ j" n0 l, D C (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]4 B- F& k. W+ S& i. I
setup-intersections& E7 x) ^ A( V5 h- m
end
( S1 E5 d+ [9 B) p& P6 @& Q6 g& U! |其中定义道路的句子,如下所示,是什么意思啊?
" l8 N0 P1 o: ~, J9 w! K, Y4 k- S# L set roads patches with
; \ g( R1 q1 S" ` s# h [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or8 H& Z& F0 l* X$ K
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 k5 s, l; C$ P6 x/ s! ~
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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