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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。7 S: Z" g& D2 P3 D9 m2 h3 {* J
netlogo自带的social science--traffic grid这一例子当中,4 ^1 ?* J/ M6 z7 |6 k
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction( Y# b, v9 u6 D+ @: d N
grid-y-inc ;; the amount of patches in between two roads in the y direction
: Y4 F$ C6 |$ O6 M" E. V9 e. R acceleration ;; the constant that controls how much a car speeds up or slows down by if
* x$ W, w& p) i; R4 z- c, K ;; it is to accelerate or decelerate! R4 a( W! e) |3 a
phase ;; keeps track of the phase8 q$ ]! s1 j; x! k
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure7 c/ W7 @2 u! Q2 C% l
current-light ;; the currently selected light' R1 [& j& h" n
; ^ A% O+ D( T5 a& @7 G ;; patch agentsets/ s* Z9 b2 W2 D6 U* K `* h1 N7 ]
intersections ;; agentset containing the patches that are intersections7 E3 V0 y1 D. u
roads ;; agentset containing the patches that are roads* \$ H. c1 }$ \$ o) g. Q
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turtles-own
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# |+ G) U( V: r; b speed ;; the speed of the turtle
; N# n% \( A, C$ ?7 ?5 U1 {1 M/ m- z up-car? ;; true if the turtle moves downwards and false if it moves to the right
8 x1 q) N( R/ M4 u wait-time ;; the amount of time since the last time a turtle has moved! a3 r# \6 W8 @
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6 [ Z, n& |5 Y5 O: l" z
. a6 a( t( q$ c& J, epatches-own
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intersection? ;; true if the patch is at the intersection of two roads S; c$ C3 r [; w
green-light-up? ;; true if the green light is above the intersection. otherwise, false.% w) M/ ~+ q3 m1 u
;; false for a non-intersection patches., g6 t& K6 |7 D/ E& _& N
my-row ;; the row of the intersection counting from the upper left corner of the
* t3 W& }% d d J8 N$ p, d ;; world. -1 for non-intersection patches.
! e. L" Y0 X: O/ k8 t( W% v. ^: U my-column ;; the column of the intersection counting from the upper left corner of the
' O. G' W* _0 c- \ ;; world. -1 for non-intersection patches.
0 }' E1 c1 y- q: a* M1 S" ? my-phase ;; the phase for the intersection. -1 for non-intersection patches.
5 R: o9 s6 W% _7 r& P. y% R. M auto? ;; whether or not this intersection will switch automatically.
& I' U; i2 B( x ;; false for non-intersection patches.1 ^; n" G: e, K7 e! z
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, s4 Q2 Q$ _$ e; w8 F7 r% M$ L;;;;;;;;;;;;;;;;;;;;;;* P: r* H, B% x- R
;; Setup Procedures ;;
2 c1 w H- `7 F) A Z;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
4 y, m0 @( E% l) G/ X. A) c% ];; Create num-cars of turtles if there are enough road patches for one turtle to' h7 `3 s8 c/ K8 q6 C
;; be created per road patch. Set up the plots.* {0 @: I2 x+ Z4 e% J
to setup0 ~0 x1 y; @! `) s
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setup-globals6 m" d' Y! d# ]9 m3 ~
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;; First we ask the patches to draw themselves and set up a few variables2 w7 M3 m) @3 l8 R6 i$ p: T& S+ z
setup-patches( y9 x- N/ ]- q- A6 U
make-current one-of intersections
# }; R8 K( O! t label-current0 {# {& [4 f$ j# s) {& g2 k
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set-default-shape turtles "car"$ H& ?/ }2 T, ^' z$ W8 j
- n) n, i2 g* i8 A. h1 p if (num-cars > count roads)9 t& L" f* Y. K0 }6 @( _
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user-message (word "There are too many cars for the amount of "
0 M, l8 [- W) a# \- u# K "road. Either increase the amount of roads "
5 Q' i4 l% g& n* a8 J' t "by increasing the GRID-SIZE-X or "
& Q7 y) E* X( ] "GRID-SIZE-Y sliders, or decrease the "
; t" `5 i J3 P8 }3 j5 H/ z+ c* H "number of cars by lowering the NUMBER slider.\n"
. \5 |! j* ^' b6 `) D4 B4 O' k "The setup has stopped.")* w; ]3 R; b- w/ ]
stop
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6 o4 F; r$ X, n- ^ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
6 \% I, \# S3 D0 t* \. ` crt num-cars/ m9 b' f* ]2 ^4 B; R' n! ^
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setup-cars
8 j" s7 [! O* V6 Z$ ^# j3 a4 p set-car-color
1 i3 a2 r/ n0 w) ?3 Y record-data* V( Z, m) t3 Z: h' r; s+ [
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;; give the turtles an initial speed6 N0 ~+ `. a' F- r; q
ask turtles [ set-car-speed ]# {$ e# t; G& a2 l, l0 V
# t9 Z% X! r6 c! b- c reset-ticks
3 D. Q2 b2 C) R9 Xend
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;; Initialize the global variables to appropriate values
! c( d( f7 C. I H, eto setup-globals
" p `: V7 z/ E+ X2 O- U r set current-light nobody ;; just for now, since there are no lights yet+ F6 V# m7 V$ {$ C: i
set phase 02 ]9 G% w& X9 R" h) W
set num-cars-stopped 0
! v$ E# X; W+ d( e' r set grid-x-inc world-width / grid-size-x
' Z3 e7 J9 U3 `; Q T$ j set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
! ]& @8 |3 S) w |! _8 H set acceleration 0.099
: A% p( P6 d) G7 } E2 O8 ?end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,3 q, h- y# S) s4 X r$ R4 e: `6 N
;; and initialize the traffic lights to one setting
' O) [% j: y: P( I( @0 ito setup-patches
+ P, `9 Y; o" H( N2 W ;; initialize the patch-owned variables and color the patches to a base-color' k. s) J! C( J2 ]3 |5 k0 g+ W: c7 {
ask patches, V$ [ y/ L O, r0 s
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4 ]2 C$ L2 \) i- i4 C9 @ set intersection? false
9 M1 M: i( I1 r* E set auto? false& j# ]; O, f5 j+ w. z
set green-light-up? true
! v1 C8 J1 T' Q, P1 S set my-row -1: O. _8 s; ~5 X" |- O
set my-column -1
4 A; G$ c4 u( O6 v3 J$ V set my-phase -1
- K* M) B) Q7 a set pcolor brown + 3. l' k3 a* {7 D' u+ G
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! O! }: Y1 W' G: i ;; initialize the global variables that hold patch agentsets
' S5 R1 A+ M4 t/ }# V7 ^& e% k1 w h set roads patches with
- j7 S1 n3 R: ~6 V: n' Z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) i6 i. ?$ Q' g V (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& \8 A# M' G9 \4 [3 k- W# A set intersections roads with
8 u6 m, l0 k% _$ T d2 C4 k [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and# I& D. C5 H2 e. \# u: ]7 W+ b
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 |7 J/ |1 m1 e I
B; f; J! w3 F6 u8 w3 { ask roads [ set pcolor white ]
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end
" [4 s! t. R* a1 I" K. _其中定义道路的句子,如下所示,是什么意思啊?
2 m) Q! X0 Z: y- q9 N set roads patches with. Q( B3 G% |+ h1 e- }9 J7 s
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
% V: M: s; i! D; d/ L- o (floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 t7 \# ^) J$ _' U" [- K
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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