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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。
H% r$ C5 m! L) hnetlogo自带的social science--traffic grid这一例子当中,
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" T, O& a! W1 G/ x grid-x-inc ;; the amount of patches in between two roads in the x direction; X4 [. ]1 |. W
grid-y-inc ;; the amount of patches in between two roads in the y direction; t0 \! F: k+ d8 Z6 W5 i
acceleration ;; the constant that controls how much a car speeds up or slows down by if% z( g6 ^* Q( \, a4 K
;; it is to accelerate or decelerate
y+ D$ v0 K- j- q0 o phase ;; keeps track of the phase& W) L7 P5 c1 O' U% r, z$ ^
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
) r7 z2 L- y+ b+ [7 b current-light ;; the currently selected light
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;; patch agentsets
. n, P& D7 k( i; d intersections ;; agentset containing the patches that are intersections
# _4 e8 T/ ^+ S8 L6 Z* G& ~& r* g roads ;; agentset containing the patches that are roads
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turtles-own& k3 C# R `2 G3 a( ^# l. N: p- s
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1 ]8 e, r! m, ?" u6 {4 O speed ;; the speed of the turtle
$ v/ L" g' o- ]4 |7 s! P- Y up-car? ;; true if the turtle moves downwards and false if it moves to the right' y( R6 k# w" t M9 t) w3 t
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads$ Z. c- k% |: t1 F$ P" _
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
* i5 Q1 l; p. J: }" r ;; false for a non-intersection patches.
$ {# i; m( B1 B0 X my-row ;; the row of the intersection counting from the upper left corner of the* [* m5 o3 F: w3 H
;; world. -1 for non-intersection patches.
+ }6 c, ^5 \5 j# w my-column ;; the column of the intersection counting from the upper left corner of the
( P1 ]: U D1 S7 N" E9 U0 H' k' D( u ;; world. -1 for non-intersection patches.
# K& }5 Y c- K+ n( v my-phase ;; the phase for the intersection. -1 for non-intersection patches.# }0 y# w: {2 L6 n% t7 r3 @$ P
auto? ;; whether or not this intersection will switch automatically.
* ]- Z: J1 N, b- D/ o8 Y# [3 u ;; false for non-intersection patches.4 p( _* ?6 e9 s
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;;;;;;;;;;;;;;;;;;;;;;
/ v* f1 [ b" |+ Q8 Z# L;; Setup Procedures ;;
% @1 A5 }7 \6 ]$ i: @2 G;;;;;;;;;;;;;;;;;;;;;;
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' u% \, R! P& [;; Initialize the display by giving the global and patch variables initial values.
1 F# J/ H9 J* O;; Create num-cars of turtles if there are enough road patches for one turtle to1 j8 K6 }! O0 e9 c
;; be created per road patch. Set up the plots.- Y: x/ h5 @% t5 q
to setup
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setup-globals
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1 w( e9 Z* q& ^9 f, U4 t ;; First we ask the patches to draw themselves and set up a few variables
- I) ~; b" k0 C setup-patches
: e2 n. p9 `9 H/ F, f: H3 e make-current one-of intersections. M* n+ g! N9 R6 T
label-current
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4 ^1 O1 I" a6 F+ K) A; R1 f set-default-shape turtles "car"
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if (num-cars > count roads)" n* q3 R* v# i7 K, f- \
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7 m$ u9 F3 `1 s8 Y user-message (word "There are too many cars for the amount of "
. ^9 v4 f4 O- ?: R2 ^ "road. Either increase the amount of roads "
2 X* P. L2 L) a0 _7 E "by increasing the GRID-SIZE-X or "6 Z# d) O+ u; ?- l9 \
"GRID-SIZE-Y sliders, or decrease the "
$ ]4 D! t5 O& u/ j' f! C "number of cars by lowering the NUMBER slider.\n"
/ Q1 G& g# l D1 K; R "The setup has stopped.")4 Z! m$ s1 u1 K# G* I
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color$ q3 P1 ?) c/ \/ N& c
crt num-cars# f( E7 ^. p% J# `8 j5 R& d
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7 n/ V" [2 l5 ?0 W3 W setup-cars
4 n" n- W; y# v- r1 ~ set-car-color
- H2 h2 S* {# J4 e) |0 i1 d record-data
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3 F; Y1 H% s! Z$ D4 f4 ?3 ` ;; give the turtles an initial speed
/ X) K! [( v4 m& `; i4 Y" Q1 T# m ask turtles [ set-car-speed ]6 h9 N6 `- a0 Y z7 p. l9 b
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reset-ticks' o, S- w9 d5 }: g) D& U; ~1 J
end9 W. p* t; x; k- C* L
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;; Initialize the global variables to appropriate values
8 {- q9 E, @: v' @. v2 \to setup-globals
% t# L3 P Q ~" M set current-light nobody ;; just for now, since there are no lights yet
/ j1 |$ h+ a: j set phase 0. c |* s7 D! ]: l
set num-cars-stopped 06 `/ H0 e' S+ u$ ^' {) | V$ y8 V
set grid-x-inc world-width / grid-size-x
0 e& t1 |5 v/ B% p+ C6 F1 v set grid-y-inc world-height / grid-size-y
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; J0 ]; z4 Y" {( l ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
) \" L: U9 |0 z0 h X set acceleration 0.0998 Y7 l1 X. c* R# s2 ~. D+ [
end9 H0 M3 m+ z3 K8 s! b
, G7 n) @4 ^& U5 z: y;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
2 h+ l" Q9 m0 m y) E. O;; and initialize the traffic lights to one setting, c! h9 L" {( P3 b5 W* C6 m4 ~
to setup-patches; T" I& i5 p' }. |9 {+ {/ h
;; initialize the patch-owned variables and color the patches to a base-color
; ]' W4 }& d5 W+ e) d% K ask patches
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set intersection? false6 ?& ~( U( y+ x, v! ?9 C# ]& v
set auto? false4 s! u, D6 x$ i; O# L
set green-light-up? true5 F% a) e9 [' y
set my-row -1
5 T$ h3 F% E: b) q3 z J2 s set my-column -19 m7 F# e# C) B$ y" `4 \6 J
set my-phase -16 q4 D8 q4 N- @& S2 z$ s4 z
set pcolor brown + 3' {7 P- y& o5 q1 q8 C0 b2 E i2 q* N
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3 c8 m9 b6 l0 ]9 y ;; initialize the global variables that hold patch agentsets6 k9 M( \4 ?# g# H
set roads patches with1 L$ ^" O" [; {0 }
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 f7 ?# R x0 A1 w: u, S1 P& Y- K (floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ \, e% I3 W3 k2 B7 y
set intersections roads with
" Z3 z$ B n5 X9 D9 E7 E; M# U1 J [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
) Y7 ^: M4 c' w% g (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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+ X$ I7 X0 A( N) G) f6 } ask roads [ set pcolor white ]* }/ N; X) @+ T/ X* E
setup-intersections$ }& ~- ^# b! X# \
end
& C1 i& t6 @: F/ e其中定义道路的句子,如下所示,是什么意思啊?# `' a7 P7 j! F6 Y/ j" Z
set roads patches with
5 W7 |, |, u" u, e! R6 g [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 ~3 V8 c1 y4 u
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]( {/ u' j! ]2 ?: F$ R
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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