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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。& \$ Z) b! `$ e- U- j
netlogo自带的social science--traffic grid这一例子当中,; c' ^3 J2 a& R1 K/ y) x# B
globals) _; d. i' b3 }1 a( {
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" h( |% n( s- Z1 h6 M grid-x-inc ;; the amount of patches in between two roads in the x direction
/ e7 W& ] y* V# _0 U grid-y-inc ;; the amount of patches in between two roads in the y direction
/ |8 ?9 d3 \3 R2 d8 V5 V acceleration ;; the constant that controls how much a car speeds up or slows down by if
+ E/ u* v6 N1 r8 g F! a ;; it is to accelerate or decelerate
/ i: \, z j& h( N! ?, X phase ;; keeps track of the phase+ h! Z4 n# {$ K) p2 G! X; f% B$ c
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
! p+ l; G) T6 X, q8 `* D current-light ;; the currently selected light& U, Z a1 y3 C& \" A i3 b
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;; patch agentsets3 d- L1 \: v/ K. H0 E) r
intersections ;; agentset containing the patches that are intersections
% ?1 n. F" W5 X& N0 V roads ;; agentset containing the patches that are roads
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turtles-own
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0 M" r& Y4 L7 g0 k' g+ h3 Y3 u0 |9 Y speed ;; the speed of the turtle
; ^1 G9 z, T" m- p% ?: ? up-car? ;; true if the turtle moves downwards and false if it moves to the right
* _/ W; A5 j, t! C, k( W0 O, t/ Y% _ wait-time ;; the amount of time since the last time a turtle has moved2 }8 _6 J6 Z7 k2 V+ v, B/ q
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7 U8 L) Q2 E3 b/ _8 }patches-own2 ^4 X( P& d3 q
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intersection? ;; true if the patch is at the intersection of two roads/ D* P" g/ h$ X. A0 x1 i! r
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
# z8 p1 \/ h( d4 [& j+ M ;; false for a non-intersection patches.
% Q+ d7 k* C7 H7 t1 B my-row ;; the row of the intersection counting from the upper left corner of the
& N( q. Z# H4 g ;; world. -1 for non-intersection patches.% {& X1 Q1 i3 C6 ?9 U( I8 V
my-column ;; the column of the intersection counting from the upper left corner of the, U% [1 m, u. O: q
;; world. -1 for non-intersection patches.
- O: S. U9 r3 V1 R% @' i2 j& C my-phase ;; the phase for the intersection. -1 for non-intersection patches.
$ t! O( d( C2 {6 d auto? ;; whether or not this intersection will switch automatically.: @- z& s @- H: u
;; false for non-intersection patches.% C `" B9 ]0 t& h0 e0 k
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3 V0 v* G: s4 x' I, L! ?2 ?" s;;;;;;;;;;;;;;;;;;;;;;
$ g/ U; ?! E" [ I3 `;; Setup Procedures ;;
* V+ h: `! S+ e, v0 v; `;;;;;;;;;;;;;;;;;;;;;;" N) ^5 ^! R8 Y: W
& R2 N6 E3 d2 P- L;; Initialize the display by giving the global and patch variables initial values.
( o! R" a* g* K( _;; Create num-cars of turtles if there are enough road patches for one turtle to
* l b6 w$ d: q;; be created per road patch. Set up the plots.
8 {' O: t. p, t2 b3 h) W0 \to setup
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4 d/ T/ m8 i H setup-globals
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;; First we ask the patches to draw themselves and set up a few variables7 ]" l* S" L4 m' a& H) a
setup-patches
8 o2 H+ K# i0 L* X; q" Q( _5 r+ M8 M make-current one-of intersections+ b ~2 ]( A, ]5 k! I) b
label-current3 \+ D# z# T1 C5 o
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set-default-shape turtles "car"7 P* d9 W6 @0 h
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of " V, _ i* ~9 Z9 y& `" t& _4 ]
"road. Either increase the amount of roads "& |* D7 K4 y" h6 v; o- o
"by increasing the GRID-SIZE-X or "
+ F, i P2 P" d$ { "GRID-SIZE-Y sliders, or decrease the "
' e1 k! [' Y+ w8 }% _- R "number of cars by lowering the NUMBER slider.\n", j4 p, q; a6 }9 y+ n; |
"The setup has stopped.")
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5 I5 k; ~3 u) m3 K9 l6 U0 v ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
: m# |0 N% U4 x. k$ q |4 d* C crt num-cars5 V$ L6 Z, Y( S- H
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setup-cars
& ^9 P4 [9 s; g, T7 ]& q+ {4 O set-car-color# K7 W, k; U0 R3 |4 N, m
record-data
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;; give the turtles an initial speed/ C! T4 x1 V. h9 Q1 j9 x
ask turtles [ set-car-speed ]" |( r; w1 J3 {- T
/ ]; P5 Z" t( o4 c0 q/ X# S reset-ticks
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; R2 \( m" l, s( U;; Initialize the global variables to appropriate values
d4 L6 G( L: { S) ito setup-globals
6 q; ]/ w% E% T' h set current-light nobody ;; just for now, since there are no lights yet
5 m( }8 L# O) X set phase 0
1 w! S! O% J+ w8 T set num-cars-stopped 0$ ?) s7 Q' F- y- ~7 f5 [- [
set grid-x-inc world-width / grid-size-x3 A! T: ^5 {8 x* \
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary8 s8 z4 b3 x$ Y! q8 x
set acceleration 0.099
6 @3 C( p) Z' x/ \* o( j6 r" K8 Yend+ z; s4 p% g' l! u1 w( |- ?' b
+ S6 N6 J+ a& c8 m
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
) [. Q/ V/ [; K$ C0 B;; and initialize the traffic lights to one setting/ b( P3 N0 p) d8 s, C$ m% m
to setup-patches% B( F- ]( ]- V* u5 E
;; initialize the patch-owned variables and color the patches to a base-color
1 m+ G" a: A( M ask patches( c8 N/ l3 w6 R- g9 w# O8 }# g; a
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set intersection? false9 M$ h5 ^! i& l( n* l
set auto? false& k: Y4 }' e/ n4 e% S Z Z/ Q
set green-light-up? true
: ?" q1 \" a! G( \ T set my-row -1
- E! Q# W& `8 j P! h4 ` set my-column -1
+ X+ |3 Y4 E2 T. X4 y" U* F3 Q set my-phase -1. h Q: w" d0 {0 g9 C% B8 D) U
set pcolor brown + 3: H0 Z5 ^$ ^$ ? X$ G
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( ~) C5 G& v0 b- u ;; initialize the global variables that hold patch agentsets
: F* o# |% `3 Y' e set roads patches with6 b \# U' I4 @7 v" A; q5 W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 G4 _( x1 t3 |* p6 P/ S (floor((pycor + max-pycor) mod grid-y-inc) = 0)] u" ~: L& x0 d1 G! k' ~1 C U
set intersections roads with# f2 T& O; V$ h9 B3 M$ ?
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
8 ~* i# ]4 @ x9 F7 N (floor((pycor + max-pycor) mod grid-y-inc) = 0)]% \1 }3 `2 h# p: X
2 X) l+ r( L+ a5 c ask roads [ set pcolor white ]
% i0 d* t) a e setup-intersections
, U" t* b/ ~/ Z8 a/ `; oend
& a, g) C1 h7 M: s$ B其中定义道路的句子,如下所示,是什么意思啊?) O# P' m, t4 K Q& Q% Q" {9 M
set roads patches with% x) w( C/ H/ d( {: v9 C$ [
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ j/ S, u: O! P6 S, t (floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ A+ T& U9 u5 D6 W9 t& j
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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