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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。
8 q# r8 ~( N2 O' `! inetlogo自带的social science--traffic grid这一例子当中,
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/ q, `: z* U5 m; _ grid-x-inc ;; the amount of patches in between two roads in the x direction z, _9 W* i0 r: }+ j
grid-y-inc ;; the amount of patches in between two roads in the y direction
, e0 ]1 b2 S; f% Z5 m |+ | acceleration ;; the constant that controls how much a car speeds up or slows down by if
4 Z4 Z. U; ?0 _. V9 K" I8 W ;; it is to accelerate or decelerate/ I( U* Q" R( i. {) [; z% u
phase ;; keeps track of the phase( j: G8 }0 N; G3 N4 |; D
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
; V9 L- _/ e/ `- G; n current-light ;; the currently selected light
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;; patch agentsets5 I8 v2 |8 \" f2 P
intersections ;; agentset containing the patches that are intersections
+ n* u- X3 X9 t. r7 R roads ;; agentset containing the patches that are roads& u5 @1 A. G: l1 u
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turtles-own$ k/ F2 G# a+ [$ o; h, f" k
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speed ;; the speed of the turtle$ W( b: _( M' w* }! P
up-car? ;; true if the turtle moves downwards and false if it moves to the right
T: @+ V7 {; ` F2 X% L wait-time ;; the amount of time since the last time a turtle has moved( J# A5 F U C& h2 Y m" ~% b
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patches-own
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$ y3 K" J) ^0 N! j0 a0 a intersection? ;; true if the patch is at the intersection of two roads
# F8 T1 L& K% \ green-light-up? ;; true if the green light is above the intersection. otherwise, false.2 k3 e# W5 ~/ |
;; false for a non-intersection patches.
0 K g5 s4 c3 n; w* y) d) l& T my-row ;; the row of the intersection counting from the upper left corner of the& B L4 w/ d% e0 P8 H4 S0 \
;; world. -1 for non-intersection patches.
4 w! t$ H) Y% V6 I9 q" b9 h+ F my-column ;; the column of the intersection counting from the upper left corner of the
$ C/ ~. N v O9 w; i ;; world. -1 for non-intersection patches.
J" P6 L! t" Y, ~# ~ my-phase ;; the phase for the intersection. -1 for non-intersection patches.
. X b% B! N2 ]& i auto? ;; whether or not this intersection will switch automatically.
s/ \) R: J8 U l ;; false for non-intersection patches.
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v; F4 E6 b" T3 e' F/ R* w. J;;;;;;;;;;;;;;;;;;;;;;$ V1 K3 |% ~. w
;; Setup Procedures ;;4 @% i; x1 H& ]0 W0 n! {; `
;;;;;;;;;;;;;;;;;;;;;;$ {3 x8 S# o/ f4 {
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;; Initialize the display by giving the global and patch variables initial values.7 L5 [. {" O' \7 T8 A
;; Create num-cars of turtles if there are enough road patches for one turtle to
* ?+ x/ t5 S. s1 q1 m. T8 `;; be created per road patch. Set up the plots.
1 P8 i2 w2 _, Ito setup8 H7 u* C2 l J, ]* z
ca
9 t+ ]5 O* I: E. q setup-globals+ g0 g' _; Z% X8 R( B
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;; First we ask the patches to draw themselves and set up a few variables
3 _; \$ g6 R2 G) L! r# Q4 L: A setup-patches2 C1 q9 A, p# T+ Y
make-current one-of intersections
/ u4 U G# E+ z3 k2 C' J label-current! N. ?2 h* J( I7 S1 c
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set-default-shape turtles "car"7 I2 u T- v. R2 Q* |6 z3 s
5 @3 Z9 c* {! E+ y) b if (num-cars > count roads)* w' ]2 i- W$ M7 r/ |
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7 B& t6 \ Q9 ~- I$ [1 u* s user-message (word "There are too many cars for the amount of ": G& I$ h' C* G" U8 z7 m, t$ E
"road. Either increase the amount of roads ") b' t9 Z8 l" v6 I/ X. l
"by increasing the GRID-SIZE-X or "; q' Z' a' R: H
"GRID-SIZE-Y sliders, or decrease the "# w$ W) f3 D9 v* ]% Q6 g9 y5 T
"number of cars by lowering the NUMBER slider.\n"3 {' Y( d5 @- a4 l4 O
"The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
5 R, R& a* Q; I" F- r% [$ _ crt num-cars
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' A; X9 C |& B2 ~4 C4 ] setup-cars
$ i9 o6 X; _9 x6 l8 Z' v set-car-color
8 [, m0 P7 k. l( C: b record-data5 v* I$ I7 J+ J5 H
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$ D* L3 w0 @& Q% q ;; give the turtles an initial speed
" F. g, u1 F# h: [ ask turtles [ set-car-speed ], q# [8 c: ` y- |- O6 H; D
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reset-ticks
i# @: M" u2 K# A' ~end
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6 J1 l9 ?+ e% k5 _;; Initialize the global variables to appropriate values3 ^: C% y( j$ Q( R2 ?
to setup-globals: `$ y+ d! h5 a8 |
set current-light nobody ;; just for now, since there are no lights yet( L s0 I) E* D, Z, k8 T/ X2 a1 x
set phase 0
: w4 T: z2 q' o% T. {1 {6 a set num-cars-stopped 0# q/ |1 s/ c2 C! x5 [7 R7 A
set grid-x-inc world-width / grid-size-x! m9 F% |! u0 Z0 l4 i' }
set grid-y-inc world-height / grid-size-y
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i) S/ B; G1 Y! A6 c& E, Y5 L ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary& Y$ u. s# b3 ~) ?
set acceleration 0.099; `5 \7 Q4 K& J1 @" U' v
end
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& Z' d6 i/ v$ t' F+ t4 I;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 X8 m6 \' j- q8 L/ I% s. W
;; and initialize the traffic lights to one setting
# X+ b2 X9 S3 Tto setup-patches. p! p' o# x, G
;; initialize the patch-owned variables and color the patches to a base-color9 K) l( y' k3 c+ n8 }
ask patches
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set intersection? false
' v8 j- g- F: b set auto? false
% l$ }0 h( B$ _) | set green-light-up? true
8 [8 F8 j4 X/ O/ X1 { set my-row -1
/ w e) ?0 M' s: D3 E: F set my-column -11 K) @& K* b& M* p- i! S% o
set my-phase -1% t3 A- p9 N; k. b" \$ g% p& J
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets& o) ?" s- [6 P! T' a
set roads patches with5 t& Y$ D4 f |" G
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 }/ p1 u' R$ C- i! ~' b, F; G (floor((pycor + max-pycor) mod grid-y-inc) = 0)], t+ H' q0 ~$ s9 }4 j
set intersections roads with
. j" O# i5 l# ?5 l9 D [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and; {+ v7 ]9 _8 W: }4 U
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]. \6 x2 w A1 u3 A7 s0 e( b
f" n$ B% ?* w7 F& r ask roads [ set pcolor white ]
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end1 r8 \& |. ?2 ~; c g% a- W
其中定义道路的句子,如下所示,是什么意思啊?
% y, c. y' g" M' H A" C0 z set roads patches with
5 P. P: D5 i( r0 I/ B0 z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( u: X0 Z& T: k/ G% W1 R1 j9 s
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& k% q8 M" I+ J* m; H0 g$ V/ p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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