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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。4 x1 U4 c7 l8 ~+ m" w
netlogo自带的social science--traffic grid这一例子当中,- h8 B, l( [% x. @9 a% \' L3 k. t O
globals* E. C' n! R/ R8 `3 w, B
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grid-x-inc ;; the amount of patches in between two roads in the x direction
5 E* m d) T/ m1 { G5 P grid-y-inc ;; the amount of patches in between two roads in the y direction' |- k5 N1 o3 D3 _ I; \
acceleration ;; the constant that controls how much a car speeds up or slows down by if6 C6 k+ m6 |2 p# g4 Z
;; it is to accelerate or decelerate/ o8 D8 P0 R' i9 \2 j( P" }
phase ;; keeps track of the phase
r" g( x( D% T2 ?4 J0 j num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
1 N7 L/ y0 S, M5 R+ ~3 g! o( ?' g current-light ;; the currently selected light/ j$ J* v' ]; e5 ^& s* ]( W
; @+ X" s6 O0 J ;; patch agentsets
( g3 ~9 `" Z6 }5 {5 J8 F S intersections ;; agentset containing the patches that are intersections
+ E1 n ?" u @: q7 Y; z roads ;; agentset containing the patches that are roads
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+ V0 w, i! U& _! H" Oturtles-own
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speed ;; the speed of the turtle
- g! S1 ], x9 J! `/ D5 J up-car? ;; true if the turtle moves downwards and false if it moves to the right: f- s' t& S5 [
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own# D0 C: L+ i& s& A2 f
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3 L! p) @, p( I* a# ?/ [ intersection? ;; true if the patch is at the intersection of two roads
4 T7 ]: e1 V( Q* \# X( _ F6 U green-light-up? ;; true if the green light is above the intersection. otherwise, false.
$ L, g |; {6 C4 \ ;; false for a non-intersection patches.
4 }! ]. ?: T3 | I/ }6 G6 s my-row ;; the row of the intersection counting from the upper left corner of the
5 T/ |5 K, A4 L$ ]& F1 f ;; world. -1 for non-intersection patches.% k/ q" g. A/ g' x
my-column ;; the column of the intersection counting from the upper left corner of the
& b# C& v) {4 o& W/ x2 j) I8 m7 s ;; world. -1 for non-intersection patches.2 P4 a. Q: b0 J' l6 |
my-phase ;; the phase for the intersection. -1 for non-intersection patches.( `" l! f% n5 @5 J
auto? ;; whether or not this intersection will switch automatically.
1 B# ?" H+ a' j* A; G7 { ;; false for non-intersection patches.- Z# i( ~. H- x n) x& x5 p9 ]
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7 r1 k0 z( a9 l0 W, y;;;;;;;;;;;;;;;;;;;;;;
. a8 g2 a8 z% N& n* k;; Setup Procedures ;; }9 w& H& o" G+ X7 r
;;;;;;;;;;;;;;;;;;;;;;" c' `$ v- E5 t# a* U9 s
0 A$ v# p! b) s' r;; Initialize the display by giving the global and patch variables initial values." v. H1 p# E% U. s; d6 Z
;; Create num-cars of turtles if there are enough road patches for one turtle to/ f7 L! Y) L1 M+ k6 b( A
;; be created per road patch. Set up the plots.
2 m3 O. }+ z1 Y5 ^) C0 ?to setup
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setup-globals) I o7 h8 h4 q; T, G7 J) Z
9 p& d3 T0 n9 O8 G4 \4 o5 x+ M( G" c ;; First we ask the patches to draw themselves and set up a few variables
! i0 P/ h6 a' ~" f* \+ V setup-patches: n' o' j! t7 m3 B
make-current one-of intersections
7 d2 K- p- @* _: W3 m$ f label-current8 w* {' h5 a c9 T; g
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set-default-shape turtles "car"
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, |" F; E+ h6 c. O9 q0 F7 T if (num-cars > count roads)
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2 j5 E/ d6 c Q user-message (word "There are too many cars for the amount of "
7 L5 q" q9 A4 N9 L "road. Either increase the amount of roads "" z. E0 t& R Z( D- @# \
"by increasing the GRID-SIZE-X or "2 I2 p* C- k- {# l
"GRID-SIZE-Y sliders, or decrease the "8 o. g. W8 z, W5 v# Z: y$ Y* @
"number of cars by lowering the NUMBER slider.\n"
+ K1 e3 Y) I& N% w "The setup has stopped."): r2 F2 d9 b' S
stop2 z8 d q! D+ w& N* l d
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
" E8 t5 K& S0 k( o2 H+ v% s crt num-cars' h, I! i6 l$ b4 \
[
& ^+ S5 B8 Q4 B9 v7 i setup-cars
- P8 ]) j5 c {$ | set-car-color" V5 P! {7 k3 E
record-data
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;; give the turtles an initial speed
. ^, D; \' l) Y9 L ask turtles [ set-car-speed ]6 j, I" m2 M# q3 D$ Z8 t
: X5 h: S# _, i reset-ticks
' Y k9 t# o: c" Nend
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2 i1 x M# h7 o;; Initialize the global variables to appropriate values2 A6 H& a. z* h5 @+ v! e. B
to setup-globals
# W" p* ~5 [1 Y set current-light nobody ;; just for now, since there are no lights yet G o2 V l; F& C( z
set phase 0* \& t. y8 t: ]- m" c
set num-cars-stopped 0
! B' k. ~; G2 s& t) { F set grid-x-inc world-width / grid-size-x
* v0 G8 e, q0 U& Y* ~ 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 boundary
1 X/ ]" o4 M7 g set acceleration 0.099
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2 v- ~1 C J Z# @* T( o;; Make the patches have appropriate colors, set up the roads and intersections agentsets,, E# S3 I: U- a! H% c
;; and initialize the traffic lights to one setting
' u1 V* F( E$ g# L7 Ito setup-patches
8 l; {% }3 u0 o: K: ]. K3 C. ? ;; initialize the patch-owned variables and color the patches to a base-color
9 z) {' q2 B, f1 x3 Y. O ask patches8 b& m6 W, l6 [- F
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* G ~$ h7 |' p" H/ a set intersection? false
d; R2 s( T. D6 B2 c7 \) J set auto? false- A+ ?3 b! K1 j$ W; E/ [- q
set green-light-up? true
: h1 ~; W! |1 h6 m; W4 b) H set my-row -1% ~5 k! o0 m! r, S( f
set my-column -1
' @$ S$ {, B. |' x+ X set my-phase -1
, l6 ?0 a0 U' |% ~ set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets {6 k4 q" `, e$ S
set roads patches with
) o9 F) _2 S0 A [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 ~$ B+ I6 W, q- N) j1 @7 n4 j f (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 L- ` B/ _$ r) n' R+ C
set intersections roads with9 O, {: n$ a' V
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and. [5 P8 b7 J# j+ M8 c
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]) y w. J( t( T
6 A/ e! @" P* L ask roads [ set pcolor white ]( ` _/ m' ~, D: c$ y9 z6 b
setup-intersections
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+ v4 z2 E: P3 S$ i: d5 E/ I# R其中定义道路的句子,如下所示,是什么意思啊?
# p H5 U1 x5 j0 {+ T2 ]- H4 ~ set roads patches with9 `0 t7 n# _; ?' \. x; @7 A' o) k
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# i, e# [, Z' ?6 L- ~% b (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) }4 c+ Z0 m& R+ ] I# W* t/ W
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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