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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。/ K0 Q7 n. I$ N* Z1 _! F
netlogo自带的social science--traffic grid这一例子当中,
. `9 e# D5 K( N8 a6 Z" x5 h5 X: Tglobals- B. i2 l5 b4 H! Y6 z4 p1 J; t9 X3 U
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# V! N7 C/ l7 N) X7 E' c, A grid-x-inc ;; the amount of patches in between two roads in the x direction B; {3 v0 X" `: ~, |# r) s9 }! V
grid-y-inc ;; the amount of patches in between two roads in the y direction s+ [% j0 M! ~0 } _, d
acceleration ;; the constant that controls how much a car speeds up or slows down by if" _0 w, ^+ ^( f) O8 I& V
;; it is to accelerate or decelerate
) k( u7 F6 W8 v0 b% F; A0 t phase ;; keeps track of the phase- l" S! } O+ P% Z: }8 f' G
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure, L# }) O( }* m, K' `+ U
current-light ;; the currently selected light9 }1 h" I. e% l
, n/ o( ^+ d' U5 u+ M K& {: m" ? ;; patch agentsets5 z: E! w7 q5 D, D0 ~4 ]7 [- A
intersections ;; agentset containing the patches that are intersections
( _+ Q* m& `. |* O roads ;; agentset containing the patches that are roads$ I1 A/ g: @( r* r
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turtles-own0 O3 A1 U7 F5 n7 j3 i
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% {- @( Y0 X& k& n' W9 [ speed ;; the speed of the turtle
+ u( j) L! ]$ j up-car? ;; true if the turtle moves downwards and false if it moves to the right2 s) G1 J) ~: n
wait-time ;; the amount of time since the last time a turtle has moved& y ]" r* \* |# C0 }& ^
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" z2 \! ~6 s) p8 L5 Y$ U) upatches-own/ J1 n3 y$ a5 l' ]5 f' i4 ^
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intersection? ;; true if the patch is at the intersection of two roads
* g4 P+ J& N$ I% o; p green-light-up? ;; true if the green light is above the intersection. otherwise, false.' a, d$ ~0 m4 @& n$ F
;; false for a non-intersection patches.) I7 V) E& V* o- S" _( i
my-row ;; the row of the intersection counting from the upper left corner of the
' E6 G$ ^0 T: N4 V( U4 Q! q8 H) W ;; world. -1 for non-intersection patches.
; K8 Q) A- P/ Q my-column ;; the column of the intersection counting from the upper left corner of the
" C( x Q2 i6 G, P ;; world. -1 for non-intersection patches.
; f% I" f- n. k my-phase ;; the phase for the intersection. -1 for non-intersection patches.. a% p" |4 X4 v9 C: }
auto? ;; whether or not this intersection will switch automatically.$ l( d7 n* R/ ~4 ~) D* x
;; false for non-intersection patches.* m0 I+ x) `: Z: ?, m
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% ^$ S+ O/ l0 f! w( P. }. I5 H5 E
% G$ x( n5 ~- M5 j;;;;;;;;;;;;;;;;;;;;;;
0 i1 z2 B- i6 ^0 n7 h;; Setup Procedures ;;
4 b/ e3 G" g0 u7 t. ~$ H: f8 };;;;;;;;;;;;;;;;;;;;;;* Q6 x C- o9 o6 g
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;; Initialize the display by giving the global and patch variables initial values.1 } l; ]; q* E/ y
;; Create num-cars of turtles if there are enough road patches for one turtle to, I W2 F5 `& \6 i d ~1 x
;; be created per road patch. Set up the plots.
# N" W* V1 ?8 Nto setup
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setup-globals
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5 Q+ M- `6 |4 B$ r ;; First we ask the patches to draw themselves and set up a few variables
3 \% W" c- K }$ ^6 B) T2 ^3 O setup-patches g: w2 \5 Y& m# y X4 \
make-current one-of intersections) L& D" V5 V \( T% D
label-current! N, |/ H, Q% b, e+ ^
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set-default-shape turtles "car"
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; s7 H. I$ C2 f* W: d! A% } if (num-cars > count roads)) r( i1 j; G. y1 y$ h$ p- L. H
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( W* c" I5 N U5 F user-message (word "There are too many cars for the amount of "! g- p3 ]7 v3 f- @. l z
"road. Either increase the amount of roads "
5 _- q0 k+ E/ f! W# D- T" R "by increasing the GRID-SIZE-X or "
* U4 e: l1 K R* i6 | "GRID-SIZE-Y sliders, or decrease the "
8 k- g2 l0 d3 |% H$ W2 l9 A "number of cars by lowering the NUMBER slider.\n"7 i t5 l6 W2 d* n
"The setup has stopped.")
( T. T+ k# H4 X, B- ?, d: C9 d stop1 [, }$ m2 U. r
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color& {$ l7 g* y* X: J2 R
crt num-cars
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setup-cars
5 k5 p% l% A/ z; H5 b6 h) u2 S8 Q set-car-color# q2 t6 z/ t: ` b z! K7 N* n
record-data
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;; give the turtles an initial speed
. N8 O& v4 K" u ask turtles [ set-car-speed ]
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reset-ticks
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;; Initialize the global variables to appropriate values7 `/ p+ C I% }
to setup-globals- \+ y0 Z6 q/ F* h
set current-light nobody ;; just for now, since there are no lights yet2 \+ S7 X7 W2 I3 N2 w/ P( ]
set phase 0/ M" g6 j+ z. ?) N
set num-cars-stopped 0# C# A/ ^' u2 ~5 g
set grid-x-inc world-width / grid-size-x* u8 P# ^ M. m" m
set grid-y-inc world-height / grid-size-y
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$ ^5 B" g- Z8 x, q( o# Q x+ j ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
9 v9 K) b2 o6 d& I2 [. W7 | set acceleration 0.099
) }( z& I3 l6 \end$ d4 |, p7 v# F4 M4 S
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,& O& ^# {9 ~1 \7 E
;; and initialize the traffic lights to one setting
! W3 z! @2 A5 i$ C3 C' Ito setup-patches
( q1 z" j8 Z4 i2 Q ;; initialize the patch-owned variables and color the patches to a base-color2 A$ N# s+ S1 c1 I+ i
ask patches( Q- J1 v1 Y: i" D3 x) B: A. s' y7 P) _
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set intersection? false
2 D7 i8 a1 m$ e0 K. `, X0 _4 A8 \ set auto? false0 ^" m- d8 f3 i/ W" g! d l$ z# z1 r
set green-light-up? true" d2 C" q7 d: J4 ]! ^2 Q7 ]
set my-row -1
9 u' v7 J( q6 k0 G- Z( t set my-column -1, x( s& q2 G0 q9 |) [7 M" X
set my-phase -10 K( ~% A) {) l$ o
set pcolor brown + 3* L6 a0 m5 B0 l3 L t6 M
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' [5 P% y& ~' B: b8 h ;; initialize the global variables that hold patch agentsets Z' L1 _. \/ X
set roads patches with1 o2 ]0 k8 v$ u! z/ y( ?
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
& U, U2 P# p% y1 Z$ X (floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 K$ ], C( q+ M$ x
set intersections roads with$ j$ F% q; u4 V
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
* E5 L* A: C' {# H+ B7 J (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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( n3 ]* E% u7 E4 F6 E ask roads [ set pcolor white ]# E: ^! h& Y+ P# K7 H8 U; A$ ?8 H
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?
5 O+ t, f8 [2 K set roads patches with
0 I5 s0 b2 b+ X1 ?$ g1 s [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or S6 t9 x& {# @5 D8 F( [! @
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, C& T6 T9 x$ v6 l) z# r1 ^) q: n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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