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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。) P( g7 l9 _4 f/ F: N _! f
netlogo自带的social science--traffic grid这一例子当中,, g* q( e+ G5 [2 K" a, d
globals: i7 {$ Y" K3 l f- k
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grid-x-inc ;; the amount of patches in between two roads in the x direction
4 @! c4 Q9 h |& L/ `) G* ` grid-y-inc ;; the amount of patches in between two roads in the y direction: k1 l* ]2 {0 k# s
acceleration ;; the constant that controls how much a car speeds up or slows down by if4 {2 x* V0 Y/ T( V
;; it is to accelerate or decelerate
% ?6 B$ C# Z2 m phase ;; keeps track of the phase5 Q+ r! r1 S- K' L$ r4 u
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
/ J% S. [5 f! X: N8 {9 K3 [ current-light ;; the currently selected light
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;; patch agentsets7 H/ \6 }6 _% J% a
intersections ;; agentset containing the patches that are intersections
) P9 q$ {) X8 c$ ^$ ]+ O; k3 a# A roads ;; agentset containing the patches that are roads8 y8 T8 ?* \( x1 q: j
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turtles-own% P% h4 F- A( W0 p
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speed ;; the speed of the turtle6 p" B2 N4 _. m# x
up-car? ;; true if the turtle moves downwards and false if it moves to the right; \! j" I* ^. s9 F% F: ]. D
wait-time ;; the amount of time since the last time a turtle has moved; J- r/ W) Q" d
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; `! o8 P5 B o% y8 c2 d" a. Hpatches-own0 f5 W& [- @( j+ [* m& f' t
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intersection? ;; true if the patch is at the intersection of two roads4 s) D! l( n* U. ~ I1 \5 J% U
green-light-up? ;; true if the green light is above the intersection. otherwise, false.* H m) ?9 {( ` S. E9 V
;; false for a non-intersection patches.$ y! m8 `9 i+ F
my-row ;; the row of the intersection counting from the upper left corner of the" J- f. W W, Q, k
;; world. -1 for non-intersection patches.
7 I! |% k+ X& d( ] my-column ;; the column of the intersection counting from the upper left corner of the) }# X4 V3 ? y! H, \2 o( b0 E
;; world. -1 for non-intersection patches.0 ?, N, C% _6 M p
my-phase ;; the phase for the intersection. -1 for non-intersection patches.( l: o' n- n8 W5 B! @: L& A
auto? ;; whether or not this intersection will switch automatically.
/ j1 A5 o3 y; j8 p" M: n ;; false for non-intersection patches. u4 H; B: {2 D8 C1 W+ i
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9 [4 k d# _1 a9 G4 Z2 M& A5 V( `1 e;;;;;;;;;;;;;;;;;;;;;;
! T1 P# N2 L: I9 Z' }8 Q% J2 y;; Setup Procedures ;;7 C" C b6 M, G! e7 A" X7 A
;;;;;;;;;;;;;;;;;;;;;;0 D5 P- w' ]. U2 U4 E' |
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;; Initialize the display by giving the global and patch variables initial values.
" I. x8 B; K. `7 |;; Create num-cars of turtles if there are enough road patches for one turtle to0 A5 H: U$ k* U! A; X1 x
;; be created per road patch. Set up the plots.
6 Y' b2 h/ O( ?4 k& B9 ito setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables5 \6 m" [2 J" z1 v2 Y
setup-patches
( ^/ I! d3 \6 L2 \ make-current one-of intersections* y2 y: Y, G' J9 A
label-current
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! t4 U6 A4 L; x, D9 q* T set-default-shape turtles "car"8 ^! Y C: h7 O0 m0 ~; m$ |
0 K6 U7 `+ L4 Y4 `6 w/ x if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
, H/ ?0 r# f R$ t* u8 {5 T "road. Either increase the amount of roads "9 b& ]) M6 j) ]5 z! u) r
"by increasing the GRID-SIZE-X or "* D, k0 R8 h; i' ~$ @
"GRID-SIZE-Y sliders, or decrease the "" v# J- D+ \7 c p4 ~ E$ X1 I$ W
"number of cars by lowering the NUMBER slider.\n"6 u. S0 w6 @% ?: W4 I$ L
"The setup has stopped.")
+ J" [+ a( L0 f x stop
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1 B: m% `& f+ H$ i$ `! @ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
0 p5 u# R# X) ^/ u" O) D. q crt num-cars
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/ d% M' P1 m9 Y& \: {* e# N+ ^ setup-cars
6 w6 D! ~- H5 R5 q% g& S6 s: U9 \% I set-car-color
# b8 o: H- X$ _' a record-data
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;; give the turtles an initial speed
# Z E6 _, ~- O# A' m$ j! J ask turtles [ set-car-speed ]% y* X3 Y2 ^8 _8 G) I* Q
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reset-ticks1 R* h6 t; E, e7 T/ P8 V
end
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0 ]- A E# [ {8 c" E;; Initialize the global variables to appropriate values% i4 @6 u2 ~3 T# A" C1 o6 X
to setup-globals
; f2 l/ V K( S' d+ ?7 _+ m2 f set current-light nobody ;; just for now, since there are no lights yet
5 J' x9 t! o ~! P set phase 00 w" X9 x/ P0 |, {5 T
set num-cars-stopped 00 T* d9 j0 T* P7 u+ u5 Q
set grid-x-inc world-width / grid-size-x! {, Q. `2 \/ N- G) H4 R- ~
set grid-y-inc world-height / grid-size-y+ I9 B3 `$ C! i- z: b9 [* ~
8 x1 G! x- G2 n ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
1 P: [" h6 [0 \' b set acceleration 0.099
4 C# t: R4 G% `9 P; ?end
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0 `( [6 L: g. \;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
' f" Q# C+ C7 Y;; and initialize the traffic lights to one setting
* v C" \* K4 Y; y7 a/ |to setup-patches
9 I3 a4 h) I5 W4 \ ;; initialize the patch-owned variables and color the patches to a base-color9 X: p& B$ C. i% b
ask patches$ Q, F* z+ ~7 a
[
* Z; B$ K' l2 |0 N8 f" u6 z; Z set intersection? false! y- f* ^5 ?, b
set auto? false3 `% j# V& [ f1 O2 F
set green-light-up? true
$ K4 A. w$ r5 T4 x+ i set my-row -1
2 ~" R0 o# \2 j0 a W set my-column -1
0 e. G0 g8 R# A) J( [( n& A/ ] set my-phase -1
. w8 m# h0 W6 x; I/ n set pcolor brown + 3; K a6 w2 z8 s7 v# X! c9 h
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7 J; X3 R+ H7 d6 u, q2 A ;; initialize the global variables that hold patch agentsets
" B+ ~4 |& \- E$ r0 Q+ Z* O. \' U set roads patches with
( V: E( b0 G; O7 ^ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, S7 ]! U( [1 V0 c# d( J$ g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* S5 c. r# W S7 j6 |# X; z; C set intersections roads with
1 h# t& |5 A8 M [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
3 Z1 o2 Z/ G% F (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
5 y3 W/ ^. @* m3 m- i setup-intersections* T& |0 R* O2 c* b
end, i: m9 S5 G4 r# V" Q: a4 [( F1 e
其中定义道路的句子,如下所示,是什么意思啊?
2 O. l. Q& ]1 j set roads patches with6 u# P6 Y7 b" L/ ]8 H" ?( z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ f- y" X- h- d! L/ E
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 d" M, i3 M& C1 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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