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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。% G: V- \* E3 C% N& B
netlogo自带的social science--traffic grid这一例子当中,/ o+ E: q2 [- v8 i3 M6 F0 ?
globals& s3 H) t/ E" z. f% j% @( v
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1 k# W( d9 ]1 j grid-x-inc ;; the amount of patches in between two roads in the x direction
1 g: l& H# O. B grid-y-inc ;; the amount of patches in between two roads in the y direction
0 B0 V0 t) V0 o! C acceleration ;; the constant that controls how much a car speeds up or slows down by if* O V8 F* j+ `, B* x1 A1 D
;; it is to accelerate or decelerate' f( s8 Z. l% [/ W; U$ W4 b) y7 m
phase ;; keeps track of the phase
j0 j) A2 s* ^1 J/ ]0 G num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
3 G, B; a; d: z" r3 ~6 n, D current-light ;; the currently selected light8 ^9 w9 }. s) \7 ]. j. K0 Z e9 J$ i
$ i) a3 O' v/ K ;; patch agentsets
: `4 j5 I6 R! V! }4 R intersections ;; agentset containing the patches that are intersections. z9 E) c4 F+ k" O
roads ;; agentset containing the patches that are roads
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7 X+ C" @# o1 W. Yturtles-own
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! R4 v D- N! x) B* {7 _ speed ;; the speed of the turtle/ A* q% J% g" h
up-car? ;; true if the turtle moves downwards and false if it moves to the right" Y7 K) Q9 U [# D3 d
wait-time ;; the amount of time since the last time a turtle has moved
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; {; `6 f2 @4 w# Ipatches-own* a8 {2 z4 T3 o! f
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intersection? ;; true if the patch is at the intersection of two roads7 x/ ^3 x+ D% { m$ L1 u
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
& n9 k" Q8 |4 j. e ;; false for a non-intersection patches.
! J3 q3 L1 @$ R3 I* f1 z+ v my-row ;; the row of the intersection counting from the upper left corner of the
( e6 |4 r* `1 z" w, i0 v1 k ;; world. -1 for non-intersection patches.& y, Q9 H/ p4 a9 C& s5 [% a9 F8 q
my-column ;; the column of the intersection counting from the upper left corner of the
8 Y, P* ~: k6 e0 d5 i$ [ Z8 m7 @ ;; world. -1 for non-intersection patches.
8 e9 T! @9 g5 R my-phase ;; the phase for the intersection. -1 for non-intersection patches.
2 O+ C) c$ I1 _$ n7 B auto? ;; whether or not this intersection will switch automatically.
" U) Q, I+ J: L6 ~+ f& O ;; false for non-intersection patches., z+ y! \/ _7 A( c% K' a) Q n
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;;;;;;;;;;;;;;;;;;;;;;4 ~, d% x8 x' T: y; f
;; Setup Procedures ;;
; x% ~) @; K2 ~4 Q5 {' l;;;;;;;;;;;;;;;;;;;;;;
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" D3 x' L) x. p/ P+ U. T, g;; Initialize the display by giving the global and patch variables initial values.+ H+ k, J3 D6 m+ k& [$ J& `+ }- c
;; Create num-cars of turtles if there are enough road patches for one turtle to: Z0 ? e& n3 T1 ^$ I
;; be created per road patch. Set up the plots.% d0 a% o% j0 x; @: B% L8 [2 N
to setup
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setup-globals& s% S6 Q1 o* x; Z
2 \8 p& K0 y, [# I. _' W& o+ E. W [ ;; First we ask the patches to draw themselves and set up a few variables
. E$ l8 } H2 g% k) n+ f( f setup-patches: A3 ~" f: H6 V8 R- W( [
make-current one-of intersections
/ Q* `# u( D8 K2 W. P/ W& M label-current( Q( E5 O t- d
( B& O! o2 H! I- }' ~3 z1 V7 p set-default-shape turtles "car"
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if (num-cars > count roads)3 _9 n! d6 \3 F8 Y
[( i5 W- y" B2 _3 o+ v4 X5 W( @
user-message (word "There are too many cars for the amount of "
( I& H4 ^' @! Z; G0 } "road. Either increase the amount of roads "
. o- `5 U" N' w( ^2 d "by increasing the GRID-SIZE-X or "1 X7 v8 _, c% Q0 j2 L1 }
"GRID-SIZE-Y sliders, or decrease the "- @6 D+ K* b4 u. W' Z
"number of cars by lowering the NUMBER slider.\n"4 x% o* X! @3 m
"The setup has stopped.")
- }6 Y' P/ p/ S; V j stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color) c" t+ t$ v$ _9 C
crt num-cars/ W9 h, L& r1 m) y6 _: W
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5 @# M0 E6 L' _. e setup-cars# j) {1 n1 Y- D. p4 E+ j0 |( u( q
set-car-color: H# C; Q( `! p, P
record-data" j. x( E! h7 _
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;; give the turtles an initial speed" i) ~& @5 D, o+ X: u6 m' [% }8 }* T
ask turtles [ set-car-speed ]: E: L& f2 S. h% q; t& v6 {/ f, b
2 {: {; j. j& z5 g+ A& e reset-ticks
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;; Initialize the global variables to appropriate values w% O; E0 Q3 G( p
to setup-globals
: m3 D3 Z3 q& S" T3 w& k1 Z set current-light nobody ;; just for now, since there are no lights yet U7 ? `8 F& {2 Z
set phase 0
9 T: r7 O/ t2 n) ]9 w( q set num-cars-stopped 0
8 }% W0 ^3 ] k; {9 G1 X" @! _# M set grid-x-inc world-width / grid-size-x2 z) v, X' ~2 O
set grid-y-inc world-height / grid-size-y( D9 h+ x3 r/ j q0 c: P6 v2 _6 {
% ?/ F3 T9 K) j- Q( _5 E
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary: P, a, @, i5 e( ]" Y% J& o
set acceleration 0.099
: _5 h) `) _9 L& ]end0 f$ \6 |, D _/ y0 u2 K
# f$ j7 F, \) D;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
+ n6 G0 r9 T& a% k. H& |$ [! g;; and initialize the traffic lights to one setting; _; p3 r" W g2 Z c3 k
to setup-patches, U5 l/ L5 g2 n$ X
;; initialize the patch-owned variables and color the patches to a base-color0 ^% U& E6 g) [5 g
ask patches
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set intersection? false
; x; E# V/ Z% x9 `' P3 `* O set auto? false
! [: u8 r& h5 ]$ |0 m: N set green-light-up? true
3 T6 n$ T: c( U* g; P" |$ Y6 \ set my-row -1
( o" ^/ a3 B2 \5 D+ i8 B7 o1 f* o set my-column -13 D+ l5 F. ?, Y2 y. P
set my-phase -1
- K7 L) ^( n$ F. R. d8 d set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
: Q0 v4 u4 S' F: J! | set roads patches with$ |3 `' w# V# t* ~9 W: u+ ~
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
% M- F# f$ r9 e# f- \ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 Y2 |: ~4 U2 M: t/ B, g; n set intersections roads with7 s: x5 j4 V0 q5 P \
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
! r- [: _; S4 P4 a2 ~8 e/ v* t' I (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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, d( V' D! v8 u4 g' ~5 P, n0 N! E2 B9 F ask roads [ set pcolor white ]0 u4 L. `0 x3 z" i4 i
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?9 k/ O/ e2 Q5 j4 L3 l
set roads patches with
7 u8 \4 \" p! }$ C5 f3 M [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 M: F4 C: v% R2 u2 y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 \+ ?8 |+ P( `/ O L1 l/ |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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