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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。& e7 V( u/ F7 w" K7 U# Y
netlogo自带的social science--traffic grid这一例子当中,
' G7 E, [8 U# Y" a, hglobals% W5 L7 Y: [6 M2 D# |$ h
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grid-x-inc ;; the amount of patches in between two roads in the x direction
. u6 V. G1 @. o grid-y-inc ;; the amount of patches in between two roads in the y direction
& R b* ^- G" f acceleration ;; the constant that controls how much a car speeds up or slows down by if* n& |3 S0 E S/ R
;; it is to accelerate or decelerate$ V# d0 @9 G; K* r" s) C' T$ ~
phase ;; keeps track of the phase
' t1 E, W$ [8 c* i6 j/ U num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
' v9 ]4 V- O u4 }/ z6 K( S current-light ;; the currently selected light9 E" k" x* v2 e1 ?2 \3 ]
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;; patch agentsets
8 T' K' r: ]* r1 i/ l: ~: P intersections ;; agentset containing the patches that are intersections3 n" g6 H% e$ y# P
roads ;; agentset containing the patches that are roads
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' U9 A# m% j2 ^turtles-own3 }; ?2 h# ]* X3 Q
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speed ;; the speed of the turtle# g3 S2 M0 M I. A( M" {# q
up-car? ;; true if the turtle moves downwards and false if it moves to the right
. d W8 k# q5 M7 E" x wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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3 k* ^& s! v7 _( W2 D intersection? ;; true if the patch is at the intersection of two roads7 T, U7 T8 t; ~. E
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
+ h. H8 y7 ?$ w+ v k ;; false for a non-intersection patches.! \3 D4 H$ y% n5 a7 ~* i
my-row ;; the row of the intersection counting from the upper left corner of the
+ v; n; c/ h0 _0 {7 B ;; world. -1 for non-intersection patches.
( t3 N; |) b# r. }: j( m my-column ;; the column of the intersection counting from the upper left corner of the5 U; m6 Z# y( l8 L9 e
;; world. -1 for non-intersection patches.
" K% u/ o2 e9 L, n0 q g) c7 r my-phase ;; the phase for the intersection. -1 for non-intersection patches.
- `2 M/ { p+ ^2 N1 Y+ o, H! {0 x, g auto? ;; whether or not this intersection will switch automatically. v& A" a8 o' V( x/ K# Y0 e) h5 x
;; false for non-intersection patches.; t: K% _* V& {3 I; h0 h* ]. Z+ j
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3 W2 a) f7 _* u k8 u! @0 S* X: T) z: _;;;;;;;;;;;;;;;;;;;;;;
# M5 q/ D7 Z L5 n$ I: z;; Setup Procedures ;;
& a* J+ W. B! o;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.8 p$ d) A: q9 s# M
;; Create num-cars of turtles if there are enough road patches for one turtle to
% R- d# B: x* v;; be created per road patch. Set up the plots.# D% o: e- L/ ?" V4 Q
to setup
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3 e9 w, O5 S b6 H% s P setup-globals. N, \. U2 N1 X3 S
' F' a! d: l7 k, L- T ;; First we ask the patches to draw themselves and set up a few variables
5 b, H0 W; ]- e8 K setup-patches
% h4 i9 C0 ?0 \2 \6 | make-current one-of intersections2 J; N d9 V% n+ r" v+ v( v# I
label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)9 o8 Y/ `- z4 q- M4 `6 o/ Y/ r+ f
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user-message (word "There are too many cars for the amount of "
. P! l% K9 Y0 d( D. h) l* P0 ~' w9 w/ P "road. Either increase the amount of roads "
% y; A5 a l4 s1 L' O+ e "by increasing the GRID-SIZE-X or "
! W) n' L/ \% O8 h "GRID-SIZE-Y sliders, or decrease the ") v* A) e1 H% @6 w% k
"number of cars by lowering the NUMBER slider.\n"
c' x3 v) P! K6 t A) @& P "The setup has stopped.")+ p A4 U, i5 k5 z0 V
stop& f7 ~0 u% a' k# O( _6 P2 {& J
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
4 J3 L, R, [+ H. p# k0 c crt num-cars$ w2 B* L# \5 G1 i9 z2 L
[
# Q) i# p9 X- u8 r& X% E' ^ setup-cars5 P' N3 ?& a8 G$ f9 Y+ e; S
set-car-color
$ g3 I0 G% f! X2 u |( p record-data
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;; give the turtles an initial speed/ l7 q& R2 k3 I! u
ask turtles [ set-car-speed ]
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- A! T% ?3 w- ]4 d- v | reset-ticks0 i- q2 b. L; F6 _
end; ?4 M9 b% V3 Y% V* i6 B/ U
/ j+ l) o2 d; x;; Initialize the global variables to appropriate values
4 D3 K. j- {7 j# _& ~1 ?' Yto setup-globals# S7 m7 U# u/ |0 k, U( K5 J8 v
set current-light nobody ;; just for now, since there are no lights yet
8 K' a; n" d- ?3 g. @3 c8 X& t' u set phase 00 b& K1 l# _2 s' _
set num-cars-stopped 08 v ]2 H- F3 i/ @& K0 X/ A+ l. O
set grid-x-inc world-width / grid-size-x; F5 @" d1 H" K2 o
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
" T8 E; T6 o Y set acceleration 0.099
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' D# r7 G0 J) Q* Q! o# d;; Make the patches have appropriate colors, set up the roads and intersections agentsets,( i& P1 y- d0 W+ A) y6 x d
;; and initialize the traffic lights to one setting& ~# k: @% C i
to setup-patches2 _7 ?2 M/ Q. N( y
;; initialize the patch-owned variables and color the patches to a base-color
* \3 A8 c2 P) ^3 m& L+ s ask patches
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6 ?1 g* W# x5 U2 H0 m set intersection? false
2 P" ^1 l5 }5 h+ a) i0 i set auto? false
. b( W. Y; }; Q6 [1 D. { set green-light-up? true1 p0 U$ j; C/ |% G
set my-row -1
0 U9 r- J L5 e% r$ q& S set my-column -1" i5 o% F1 I0 w- ?# p; \
set my-phase -1" P3 V6 y; Q6 w9 P4 [
set pcolor brown + 3" x8 f }* {, d, o# p0 w) t2 }; C
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;; initialize the global variables that hold patch agentsets* @; _2 W6 b( }
set roads patches with) V3 K& Y) `5 _
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 y+ `/ l/ Z1 c) H. j9 p
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ F4 Y) C8 @2 q" y
set intersections roads with
1 `' }# v0 L) i( m) ~/ e3 {9 ?4 o [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 t% p, h% e; O1 k. y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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u5 k3 L: j" V C3 o ask roads [ set pcolor white ]
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end
4 C8 E* w' R3 X9 g, j8 Y其中定义道路的句子,如下所示,是什么意思啊?
1 X4 |: N5 M/ d* G' j ?3 r) l- ? set roads patches with$ Q( P5 T' H5 `+ r; ?
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 F* a/ R5 H. Y" J9 S: G% d' i
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]) G( D; p; t9 Q9 A- }. W
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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