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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。3 B0 P* i7 R9 x# \" ?3 r8 N
netlogo自带的social science--traffic grid这一例子当中,
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5 {# |% D6 X7 e grid-x-inc ;; the amount of patches in between two roads in the x direction
, Z; E+ R; a! M0 M, [+ y; Q grid-y-inc ;; the amount of patches in between two roads in the y direction
2 n+ _ _; n( v7 o" { acceleration ;; the constant that controls how much a car speeds up or slows down by if
/ X& {7 J( j% y5 A- j ;; it is to accelerate or decelerate; U& d" k9 ?7 [! h. G
phase ;; keeps track of the phase$ z+ l! I" `! m( l0 C# V4 `
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure9 Q" D6 k& B1 t6 B2 X
current-light ;; the currently selected light
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;; patch agentsets; H6 d/ g9 v/ _' G
intersections ;; agentset containing the patches that are intersections
. N$ r {9 {2 n `' z9 j* l! L roads ;; agentset containing the patches that are roads' b" V _$ C2 O7 h9 c# S
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2 M5 s2 x) v. B. N; ^ Vturtles-own* L) Z$ B3 [6 Y
[
/ P! ~) m1 _" g% `' S, \ speed ;; the speed of the turtle
7 w- z/ E7 X4 p& n, W up-car? ;; true if the turtle moves downwards and false if it moves to the right
- T/ @" [$ _% d( d wait-time ;; the amount of time since the last time a turtle has moved6 r- C4 U. N7 S5 I, F
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8 x. C9 G$ ?" w1 z$ j4 }patches-own
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intersection? ;; true if the patch is at the intersection of two roads
8 j7 M( d9 I+ s: H+ Z' L green-light-up? ;; true if the green light is above the intersection. otherwise, false.
- @. n" y4 N- N; M; o6 y2 Q9 x ;; false for a non-intersection patches.2 O% t9 O7 Z7 _) ]/ q
my-row ;; the row of the intersection counting from the upper left corner of the+ [) c+ r( S! G% `
;; world. -1 for non-intersection patches.
& O9 t( Y0 L& k6 e" C my-column ;; the column of the intersection counting from the upper left corner of the u/ W, I \' W0 M* T
;; world. -1 for non-intersection patches.: c$ [" n$ ~; p# T* B
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
1 e3 w& U4 Y8 D$ r4 X auto? ;; whether or not this intersection will switch automatically.
% q& m3 ]! D( H' z8 z" S( R ;; false for non-intersection patches./ H* x$ U) j E9 y
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; F' r! D/ y6 T4 V/ O( ^0 n;;;;;;;;;;;;;;;;;;;;;;1 p" G4 @$ {, Q6 j2 |
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.' G) X0 ]' ?0 _3 }7 A0 X
;; Create num-cars of turtles if there are enough road patches for one turtle to
" t. N$ Y0 z0 g2 x( I;; be created per road patch. Set up the plots.
2 k' i% w% j; M, } E+ \to setup* h2 ^* G6 Q1 }3 A" {
ca
% N2 {# Y; Z& g' \) f' c4 o setup-globals$ U9 Q! t; i5 W
# h( F% }# @+ t. _: L5 X9 K ;; First we ask the patches to draw themselves and set up a few variables, q* u- a+ Q0 e) U g" }
setup-patches
/ ]' h. N. {2 M/ E8 k make-current one-of intersections: c/ [% ]/ P7 w
label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)9 B' D, Y; n: e' B: q( J
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' ^+ ~: i* B$ s+ k1 Y user-message (word "There are too many cars for the amount of "5 y. e% p$ j5 b1 f
"road. Either increase the amount of roads "" L( Z v4 I$ s7 Z% }5 m: s, L
"by increasing the GRID-SIZE-X or "
$ q& d+ P# x# s+ s& S' E7 m _ "GRID-SIZE-Y sliders, or decrease the "% z; w2 j9 Z: [+ O6 H: ^7 T6 S! `
"number of cars by lowering the NUMBER slider.\n"
" \. Y+ Y1 B/ R9 U8 @: V0 ? "The setup has stopped."). }/ N* r$ f5 I+ m
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
v4 u- I& x0 i/ ^ crt num-cars, z. F/ d9 q7 v: l# _
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setup-cars
O6 u+ q" G: R' [ y7 Q x set-car-color! f- Z6 w+ P3 i5 m( A2 w
record-data( o. Y. V7 C# q
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! ^$ `" L; h, A- O3 L ;; give the turtles an initial speed
% P& E9 t, ~4 X! L5 m ask turtles [ set-car-speed ]
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9 J, D3 g* Z7 g/ K. S( h# j1 S reset-ticks
& G4 i8 l0 s* K3 Y6 I8 p6 |; zend$ i7 R! R* o. a- u
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
# B/ i, T' b& y7 V( b1 p" I& j7 b set phase 04 q( d) g/ F6 T0 g; I
set num-cars-stopped 0
% l- u% d/ O: g5 X7 G, U set grid-x-inc world-width / grid-size-x
: o+ s, b) V9 _ set grid-y-inc world-height / grid-size-y3 C' u: C! Y& Q: Y) g4 A0 R/ i
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
; [$ H- n' z* D4 b ]8 W( }" P* r' p set acceleration 0.099
+ t v1 t' P) `9 W' _: qend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
% k0 y/ a/ }2 g A;; and initialize the traffic lights to one setting
2 p# v5 c- `+ U8 ?/ l7 Qto setup-patches
/ T5 D1 Z+ _( ^* P6 F7 b ;; initialize the patch-owned variables and color the patches to a base-color
# v) s+ ]) G( M: E; ~; k ask patches
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# ^2 ^% z7 f) N3 S; \$ M7 K" ~ set intersection? false
1 o9 z' ?$ _' I set auto? false8 B) g* a q# ~
set green-light-up? true- d. `( E$ Q! p
set my-row -1/ R, z& m1 y9 O6 x5 Y" u, z
set my-column -1
: }, x1 c% p2 g set my-phase -1; J1 Z% Q/ C5 ~1 e" |4 I; L O
set pcolor brown + 33 G% Z; l, ~3 p0 _" U1 T) U: q' D
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( r; _; L v0 J9 W3 n3 w( l' f$ X/ y* Q ;; initialize the global variables that hold patch agentsets
# U, W% `0 w. [; n8 y/ t set roads patches with
2 M4 A/ u, M: @) h* n: i- @ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
+ w& ?- J3 C5 @: X. z* [ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ |' Y6 s: d7 w/ p6 ^ set intersections roads with# c, `$ T% a, o; b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
0 l1 H: f$ H/ L( ?; |- _( G( H (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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! v% }! y3 ?& W! ` `' ? ask roads [ set pcolor white ]7 }$ w+ e3 a# |$ L
setup-intersections1 F' ]5 ^! @2 T# h
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其中定义道路的句子,如下所示,是什么意思啊?
" U, `. q, z- s8 x$ R$ b# f set roads patches with
( r" v! v1 x1 P) J! o0 {1 o [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or8 Z5 [4 z& C9 @. t* a# L1 X- G2 i
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 _ W9 J9 T F5 `- f5 ^' n' ^3 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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