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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。- F0 B. ]( Q( X0 X
netlogo自带的social science--traffic grid这一例子当中,
4 n8 x# S" U1 m0 Bglobals
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8 N" B3 A( B% W1 e6 a grid-x-inc ;; the amount of patches in between two roads in the x direction
( E! J) }* n0 e1 M2 T( X7 r. ^7 a/ R grid-y-inc ;; the amount of patches in between two roads in the y direction
D% @2 v4 `/ f! {% c acceleration ;; the constant that controls how much a car speeds up or slows down by if8 H; d2 H" U: x& x1 L( o3 B3 ]
;; it is to accelerate or decelerate: G0 b8 H5 U/ Y2 ?! J
phase ;; keeps track of the phase+ E; z" k, H* p7 y9 X
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure" r* S. d% v( I7 R5 I+ X
current-light ;; the currently selected light
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;; patch agentsets% O4 y$ }4 y1 ?7 X$ d( k
intersections ;; agentset containing the patches that are intersections8 s" I% s2 @+ c
roads ;; agentset containing the patches that are roads5 Z6 J7 U8 P" Y6 H$ f! ^7 C# Z/ j1 z
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0 C/ k. E2 C4 ?% }, s+ }, U# Uturtles-own
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speed ;; the speed of the turtle
( Y) d+ ?8 \+ J) r( w& \ up-car? ;; true if the turtle moves downwards and false if it moves to the right1 Y( `+ L: z5 x+ e% ^1 S6 m$ Z: g" y9 J
wait-time ;; the amount of time since the last time a turtle has moved% A9 S. ]+ A, R& }- m
]
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! |2 f8 B0 x Z& x! {' Vpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
. v3 Y8 K1 o: D5 G3 t5 f green-light-up? ;; true if the green light is above the intersection. otherwise, false.
* O! E9 o9 P0 W ;; false for a non-intersection patches.+ E, S+ t x5 C, c2 v6 J3 D
my-row ;; the row of the intersection counting from the upper left corner of the% r7 K8 a# {' |# i0 S
;; world. -1 for non-intersection patches.
3 x( y H2 r _6 K% ? my-column ;; the column of the intersection counting from the upper left corner of the
/ T8 v& _8 X+ ]' ?) K. i0 f ;; world. -1 for non-intersection patches.) {' Y' A$ }$ h6 O" V
my-phase ;; the phase for the intersection. -1 for non-intersection patches.* ]# W$ o( q1 d0 g
auto? ;; whether or not this intersection will switch automatically.0 }0 o+ S$ k8 W: w. z. K
;; false for non-intersection patches.% b- T9 D! D+ L7 M$ j) O( R8 p1 {
]
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7 |- q" ]/ Q6 C. b: z0 Y;;;;;;;;;;;;;;;;;;;;;;+ r- ~: T* Y" e: E9 |
;; Setup Procedures ;;
4 c0 j) p3 L2 Q/ ~! g+ s2 f;;;;;;;;;;;;;;;;;;;;;;
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1 J# v& v! }3 S3 V% M4 p;; Initialize the display by giving the global and patch variables initial values.8 Y- X3 ~ `" j4 {! k- j
;; Create num-cars of turtles if there are enough road patches for one turtle to8 m4 K+ _' H% S9 U- u
;; be created per road patch. Set up the plots.) W6 K) s/ m) l6 Q1 ~
to setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables8 g" P7 y- E( o4 u3 j) o
setup-patches+ D0 q4 x. H2 T3 v8 S7 `- }
make-current one-of intersections3 |/ y& a' d+ h! F0 T
label-current- N/ ^! Y4 Y9 R0 I
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set-default-shape turtles "car"
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% o- P, O' X- r5 Q; |0 u if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of ". r# a5 ?* @5 X( `" h O
"road. Either increase the amount of roads " Z" Y1 J) n F3 r
"by increasing the GRID-SIZE-X or "# I1 Q0 ^/ h* e1 \* W2 m6 l- c5 K
"GRID-SIZE-Y sliders, or decrease the "% r( A2 q) f7 F
"number of cars by lowering the NUMBER slider.\n"
0 a9 ` r' d+ Y/ C1 r2 s" ` "The setup has stopped.")/ ]% A0 `6 L1 f
stop- p" x! q5 B* k; E
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color. }6 g. W, U( R8 R' V- |0 _0 a
crt num-cars
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; B6 ], W% x, T1 H; V* `* n, p% P setup-cars
, H0 R j( {4 {+ I set-car-color
& ]" p, F ?3 T) [4 p record-data' N4 _& E3 T* l" O1 S0 `
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;; give the turtles an initial speed. S0 P6 T+ m( G$ s$ U; p J) l
ask turtles [ set-car-speed ]& m2 ^5 ?1 D. l* y% S0 j: w
* t2 x* E, _& Y' i8 S# R, f reset-ticks; j- \; w4 U" \
end
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;; Initialize the global variables to appropriate values& B# [4 Y; i! Y' [, N/ g
to setup-globals1 L+ V, W; o2 B% c0 K& L! P7 T
set current-light nobody ;; just for now, since there are no lights yet
& u+ ^1 w2 H- ~; q9 W set phase 09 [% O, h0 a7 c
set num-cars-stopped 0
2 j9 G; i4 K4 |5 ?" h" v) x set grid-x-inc world-width / grid-size-x) |) p0 P9 {) m+ s/ _: {
set grid-y-inc world-height / grid-size-y$ e9 d: T& ^% O4 Q) Y* ?
3 f4 N9 H7 j, i! p# n ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
& M: F, v, M6 u8 A set acceleration 0.099
o! u1 u$ g6 bend
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- n$ j# R8 y! F. `6 X6 ^ };; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 h" U& Z6 f' R( p;; and initialize the traffic lights to one setting3 D( L9 K P% _/ g
to setup-patches
3 r/ x3 `, P0 r' M1 i5 D- t ;; initialize the patch-owned variables and color the patches to a base-color
) v' x- f, F& Y ask patches7 G4 c1 I% [" d8 Q
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set intersection? false
" l+ }7 G) W7 ?5 E9 e set auto? false" n: w. A, Q/ S1 Q
set green-light-up? true; G! ? \, y$ k" u% }+ r0 @% S
set my-row -1
: t" u1 X1 h5 O set my-column -1
# C6 Q5 i: S- g. Z5 R/ ~3 ~" f set my-phase -1, C8 r! w' G4 d. o/ y
set pcolor brown + 3! l$ U: `' }7 y% b4 Q; @
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;; initialize the global variables that hold patch agentsets3 ]! f/ Y6 ]" U- F2 L
set roads patches with" K( z1 L+ P, S' w: S
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# V, j; t( c1 { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( ^: Y& K% Q. U7 {- i) n* C6 ~0 ?4 @ set intersections roads with
8 D+ P" ]% z V1 M1 n [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
! P5 E/ k; u1 L+ B% S5 Y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 M8 M& a6 |7 C2 h g4 y
! p5 {* d7 S2 |* ~2 b0 m3 E, m ask roads [ set pcolor white ]
1 b" V0 g/ N) E: @ 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?
8 Z O* {- ^, j( g set roads patches with& ~/ E. Z7 F; ?' }( T
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! U% j+ J4 t# b# s* s$ z. Z# m. T* H0 U (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ N" W/ |( @' | 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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