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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。( N, E8 g' O& M) v! O
netlogo自带的social science--traffic grid这一例子当中,
% d; l k6 G$ G1 wglobals9 G# G, K1 h( ^, w, S
[
5 s! e+ y: P+ p: k; Q y grid-x-inc ;; the amount of patches in between two roads in the x direction) z4 v: r7 ^# Y, n- d1 K" F, J3 t7 F
grid-y-inc ;; the amount of patches in between two roads in the y direction0 ?2 j3 l$ i1 A7 D' A3 w, P
acceleration ;; the constant that controls how much a car speeds up or slows down by if1 \- L a0 c% l Y d) h. q6 l
;; it is to accelerate or decelerate! R* {2 M: S }9 Z
phase ;; keeps track of the phase1 a4 l9 I& b+ j' s6 [6 ]
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
3 u) Q- U6 E" Q3 G! n current-light ;; the currently selected light- B: u1 }: M6 C0 Q
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;; patch agentsets
& a: c! w3 ^+ p v) M" i intersections ;; agentset containing the patches that are intersections
. Z8 d j$ H7 h9 \" |1 n roads ;; agentset containing the patches that are roads5 h, I! s7 n9 d) D
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" h/ \3 v8 `$ `9 h w0 d9 Lturtles-own7 P& Z$ Z8 }# U/ x j. ]
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speed ;; the speed of the turtle
) R* F8 v8 e6 K( i. v0 F up-car? ;; true if the turtle moves downwards and false if it moves to the right
7 Z. D4 P0 f$ ^+ _ wait-time ;; the amount of time since the last time a turtle has moved7 Q' k5 ]+ u; i/ z& d2 V. O
]
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7 b& U6 j9 X0 bpatches-own" @# i( E, ]* L( p
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intersection? ;; true if the patch is at the intersection of two roads
: }0 B$ @6 b/ D/ W+ ` green-light-up? ;; true if the green light is above the intersection. otherwise, false.
: n/ K9 t( E1 X! Z/ X5 B ;; false for a non-intersection patches.' i/ p% h- |2 }- u( z4 q: G
my-row ;; the row of the intersection counting from the upper left corner of the6 D( A; w; x" [, i" O; K) S
;; world. -1 for non-intersection patches.1 N, b# M' |6 u+ G1 m) v
my-column ;; the column of the intersection counting from the upper left corner of the0 Z1 S% f* Z! |! N- q5 R' K$ i
;; world. -1 for non-intersection patches.
- M, C! u8 s( U. l) z/ d! A my-phase ;; the phase for the intersection. -1 for non-intersection patches.6 v/ }0 L0 j$ K8 ~# t, ^$ c0 u: y. B
auto? ;; whether or not this intersection will switch automatically.% u4 q- v3 d# G$ B
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
- E( K* t$ B4 E$ I% O* q;; Setup Procedures ;;
9 s- }; c% |) u# t; o, y- l2 H;;;;;;;;;;;;;;;;;;;;;;
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* K* R5 V6 x" `% N& U# {8 c;; Initialize the display by giving the global and patch variables initial values.1 k1 T) w$ d% c7 O9 c9 o" E
;; Create num-cars of turtles if there are enough road patches for one turtle to
9 A- { a. [9 V4 m;; be created per road patch. Set up the plots. _# M% R" C+ G; O
to setup9 y9 Y; ~; y5 j
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setup-globals9 z1 v- M3 q) G& c# H; u
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;; First we ask the patches to draw themselves and set up a few variables6 `0 ?: A) J) r% a% W7 c
setup-patches
% V' D; w+ W- b8 t+ [6 ? make-current one-of intersections
6 ?: G0 }* {+ i label-current
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j1 Z; N9 x/ l# k) C( C2 T, r set-default-shape turtles "car"7 X) Y% z* p, j# K1 B T% C/ a
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if (num-cars > count roads)0 h% G$ p1 u# ?+ G8 p
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user-message (word "There are too many cars for the amount of "
6 n$ I0 W( @) ]7 ^& o* O- v "road. Either increase the amount of roads "- h7 w. \' Y$ D7 `. F
"by increasing the GRID-SIZE-X or " h2 ^% f9 X% I! [
"GRID-SIZE-Y sliders, or decrease the "
l R; k& b) _# t' w% _. n "number of cars by lowering the NUMBER slider.\n"6 o8 }( \4 H# h1 V- P( }6 Z6 }; I
"The setup has stopped."); i/ c: f$ r' o# o" }7 }; c) l
stop' i7 V `8 B' c0 _
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
/ Y6 I: l) t" Q; A crt num-cars) b% X0 w) x0 r3 ?# s8 v
[
: h7 | E: y: k4 x3 B& R0 ]$ W$ t setup-cars/ Z d* F+ J: b8 b: W. F
set-car-color
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1 @! _# ]: j/ J6 w ;; give the turtles an initial speed
0 I7 J: N& o. v' X ask turtles [ set-car-speed ]
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- @& U7 X m1 R* }4 _ reset-ticks/ }, u! P& ~- z) [! J! ~
end6 Z& s8 L( C! i( O0 X1 `) [
$ U7 O, y: Y- _, S* Z/ H) j;; Initialize the global variables to appropriate values
, G* _5 Q8 z& Uto setup-globals4 z$ h8 d) T- G6 d
set current-light nobody ;; just for now, since there are no lights yet
& E9 a. }0 ^' u1 {3 i8 T; M$ M' P set phase 0" B5 A' m& b( o& n& @
set num-cars-stopped 0$ s9 p: L- p& i; H. B, s
set grid-x-inc world-width / grid-size-x
K( W1 Y5 k" u7 K% N$ U set grid-y-inc world-height / grid-size-y
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! _. c4 i, Z9 |* `0 i1 z ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
' j- w9 m, J: s set acceleration 0.099) [0 l) T$ g5 G6 b& ~% ?
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,3 G! i6 _( |$ ^. q/ w) H: m
;; and initialize the traffic lights to one setting b6 C, G9 S5 g X, M
to setup-patches
/ Z: F s+ \, P ;; initialize the patch-owned variables and color the patches to a base-color
' V; t; }* t% k3 A7 e$ f ask patches, Z3 `1 t8 ?8 P! O. s. ~2 Y
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set intersection? false2 [" p. C! ]: p5 y! [% q! Q
set auto? false7 [2 G4 B" y4 |, O: ?, `5 r. g
set green-light-up? true% _9 f4 p9 T3 ~( g1 o6 \
set my-row -1
" a4 g- F G% t2 j a7 E set my-column -1
' j' {/ v: J1 @ set my-phase -1# y% k2 ?) N# y, ^! c
set pcolor brown + 3
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8 z7 P7 U$ Z* g% ^( z- q% t ;; initialize the global variables that hold patch agentsets0 b4 k4 y, d" L# v
set roads patches with
! n) ^; P: M9 h [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ X' I2 }- n1 q6 n. v8 F (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' _6 M" M d1 s% P% [% i- i$ v set intersections roads with: r4 V3 S4 N. J# i! F" ~, s# v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
3 F4 L' z. X" s7 a (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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0 r! v1 _: {: |. Q7 X- n* U9 s ask roads [ set pcolor white ]5 T, K; k8 j0 b
setup-intersections
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$ ~5 s- B: M1 t+ J其中定义道路的句子,如下所示,是什么意思啊?" `3 n0 d- r- |. n0 I3 v3 G8 U6 p
set roads patches with
, ?4 k# w9 j' T [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* m! v" F7 Y7 x" Y0 R
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) i: x0 U. ^: k% J* 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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