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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 o. j& m+ O) H) F; I
netlogo自带的social science--traffic grid这一例子当中,
G9 B- T- {5 @9 H4 B0 g7 C4 wglobals1 j3 |1 e9 f6 {3 x
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grid-x-inc ;; the amount of patches in between two roads in the x direction0 C8 b: M4 h; d# I( b, q
grid-y-inc ;; the amount of patches in between two roads in the y direction
: m2 E: g @1 P5 f- H/ v' X acceleration ;; the constant that controls how much a car speeds up or slows down by if
% k' a9 i% w7 {6 T( d# c ;; it is to accelerate or decelerate
8 |) T8 v+ Y5 U& A phase ;; keeps track of the phase
! p, m2 V* M# O1 d num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
# Y5 ?! |6 M* | current-light ;; the currently selected light
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9 B4 i" W) o, A( J! o ;; patch agentsets; T5 s; y) m" W) R6 I! u6 @
intersections ;; agentset containing the patches that are intersections
% ~9 e$ [- S# {( |- {) i- G8 T0 V roads ;; agentset containing the patches that are roads
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turtles-own/ s0 A! x4 y/ R' C
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speed ;; the speed of the turtle( g/ z7 o' d( B* O
up-car? ;; true if the turtle moves downwards and false if it moves to the right: D2 I7 B! V7 l8 B) _
wait-time ;; the amount of time since the last time a turtle has moved
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1 }$ H9 a5 }+ [6 _" Mpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
9 H k, h: i; a; X/ W+ R green-light-up? ;; true if the green light is above the intersection. otherwise, false.
$ ?0 B+ x( v5 y2 \- z/ m ;; false for a non-intersection patches.- _1 b; r9 r' p: H7 z- G
my-row ;; the row of the intersection counting from the upper left corner of the4 |2 ?$ L, ~0 A5 T+ G3 ]+ b
;; world. -1 for non-intersection patches.0 P b0 P+ s* l5 y$ T! {
my-column ;; the column of the intersection counting from the upper left corner of the
& s6 h- {) m0 h" p4 c$ v/ R ;; world. -1 for non-intersection patches.
" S: y& ^, v6 Y" S1 C my-phase ;; the phase for the intersection. -1 for non-intersection patches.
6 ?' g& t2 @. ~) g auto? ;; whether or not this intersection will switch automatically.) X5 b; ?* Z z
;; false for non-intersection patches.) H/ Y! T4 f% M/ C# G* F. d
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$ ]; U* C7 D# s0 ^9 [;;;;;;;;;;;;;;;;;;;;;;
4 C2 v% Q0 g% e;; Setup Procedures ;;
9 y5 u5 m+ X) E0 b2 M;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
) S/ n( O$ T2 L( Q" O8 O;; Create num-cars of turtles if there are enough road patches for one turtle to
0 h# b4 f: ^4 k3 \( E+ R;; be created per road patch. Set up the plots.9 n! W I$ @. {+ X- K+ B
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 variables
D0 y( M" X8 C& O7 q* o setup-patches0 o6 i8 H: W1 w8 l( W% t
make-current one-of intersections
; |; y2 v7 H/ c1 M label-current
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set-default-shape turtles "car"
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. d# W _0 ^+ L8 P8 k8 {' J' H if (num-cars > count roads)2 i8 j) Y' {4 A* E
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user-message (word "There are too many cars for the amount of "
5 a4 P1 Q6 G% x "road. Either increase the amount of roads "
- o" K: Y5 ?2 t9 U! o$ Q "by increasing the GRID-SIZE-X or "
- V, C( a6 k9 ^3 ~' r "GRID-SIZE-Y sliders, or decrease the "
" B# n1 h; d; W- T- r+ F+ Q- @ "number of cars by lowering the NUMBER slider.\n"
; [6 [& g! K! \/ \6 [ "The setup has stopped.")0 |2 F- t, z6 _8 }1 L
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
8 l' u1 `* y7 A6 A) H# M crt num-cars" }* m0 Y. j, p& x/ F6 F4 N
[
8 C8 a' [% j) N1 I0 x- f' y3 c setup-cars
# t, f I6 m+ ~" l- Y2 R set-car-color: z# Z- n( z7 Z2 V( [
record-data
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7 W, h1 a; r w5 M! y6 ?8 `) g ;; give the turtles an initial speed; H' _6 C, [$ \/ M% n
ask turtles [ set-car-speed ]; R, I$ N2 `6 l5 V
2 t; V' @" q7 z6 t! u" Z( s5 v E reset-ticks3 w4 M3 s5 a! U x
end/ O% z) v4 D1 {8 z j
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;; Initialize the global variables to appropriate values$ o P, h7 y% U/ m( C
to setup-globals( h9 L4 L1 E+ }3 n" @) a
set current-light nobody ;; just for now, since there are no lights yet
; m0 i- V; D! z3 H6 F4 n0 s7 w set phase 0
! ]9 m% M, U. | B set num-cars-stopped 0% q; E1 n' a$ E" ?" F0 ?
set grid-x-inc world-width / grid-size-x1 G) y1 e* i* z) m$ b4 S1 U7 Z
set grid-y-inc world-height / grid-size-y$ G$ w: Q3 p; d0 h7 x
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
* Z/ Q0 }, g8 x set acceleration 0.099# |8 e' a2 S$ `$ d9 D I
end
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- U4 T5 \: f- i3 H9 V* I8 j;; Make the patches have appropriate colors, set up the roads and intersections agentsets,( ^: m& _9 W# W5 O7 \/ N
;; and initialize the traffic lights to one setting
: M- H* u1 S5 b, G, L# Mto setup-patches+ f4 B6 {& u- T$ t0 X
;; initialize the patch-owned variables and color the patches to a base-color
/ d) ]9 @. L5 a. b7 C ask patches
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( ]7 p* T, J- k5 b& l8 N set intersection? false
* u5 e( F) E3 W1 C, W8 P set auto? false0 m" ~0 x. }# R( x
set green-light-up? true/ M* w+ ^5 Q+ U* v) v6 _7 a V4 I
set my-row -1
1 P/ M0 O5 {" W% i7 h6 T set my-column -1
_/ ~$ N* P4 J" \7 Y set my-phase -1
0 [ y* q. u1 A+ F5 J9 ]" ? set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
" z7 p4 J2 m+ Z- W# h set roads patches with
; P3 a/ F: N% F2 p6 p [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- H6 {( h' L r (floor((pycor + max-pycor) mod grid-y-inc) = 0)]# U8 W1 G8 p. |. T4 {& l
set intersections roads with* ~* p$ {1 j7 a7 d1 Z$ A0 Z6 n
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and! G) Z ~$ D; {& Y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]( o3 R O# ]% `" }% m" x3 l' I# m
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ask roads [ set pcolor white ]8 w" K' u; k' V' F( j8 A* n
setup-intersections( U( G4 v. W; J
end) S7 P3 h5 E5 W/ T5 D
其中定义道路的句子,如下所示,是什么意思啊?2 Q& V6 R* l, M i* s# b
set roads patches with
& w' S) O" z5 d2 D& u. Q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; H! [: P7 A; n+ L& } (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: v+ V! c0 _; i5 L$ H
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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