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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。
/ M! b7 Q9 T; j8 k9 Lnetlogo自带的social science--traffic grid这一例子当中,
2 y [% M: e: K$ Jglobals) y. D5 T$ Z2 f8 J: F
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" }+ q* s0 g( j6 ] grid-x-inc ;; the amount of patches in between two roads in the x direction
* l: W3 ]" a5 a; K9 h. q grid-y-inc ;; the amount of patches in between two roads in the y direction
' b5 [9 W! L4 y' r x acceleration ;; the constant that controls how much a car speeds up or slows down by if
" l7 d; i+ c$ ]) A' Y" _/ n ;; it is to accelerate or decelerate
7 v$ @3 `& C$ h, d6 ~& Z8 X# y1 C phase ;; keeps track of the phase
' K, G) i1 b" V% F. l: C num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
8 [4 Q2 d0 `& E$ m9 E9 F& b current-light ;; the currently selected light
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;; patch agentsets
+ N# D/ C! }, Y( I/ ?, ~ intersections ;; agentset containing the patches that are intersections
: [ y4 ]1 D" T- O- W roads ;; agentset containing the patches that are roads. d5 z, H/ H9 D: S
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9 `. u# m. _+ Y$ Wturtles-own% ^3 h6 I; Z- ~6 d
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speed ;; the speed of the turtle
& E. D1 G- W" P3 N up-car? ;; true if the turtle moves downwards and false if it moves to the right
1 o( @: H/ W. v& _# ^, q wait-time ;; the amount of time since the last time a turtle has moved
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' x. _ r4 S* ~+ kpatches-own
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+ o0 h, }: R; v% O/ h' u3 ^ intersection? ;; true if the patch is at the intersection of two roads3 y! M4 v2 ]' B3 Y8 b& Y: @
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
+ g- F2 I/ h" s% e* ]5 s: x ;; false for a non-intersection patches.
) L( p# A! G2 N8 Y4 o8 b my-row ;; the row of the intersection counting from the upper left corner of the4 ^$ } W T- ?6 j
;; world. -1 for non-intersection patches.6 Y1 ~2 u. D9 @6 p! l
my-column ;; the column of the intersection counting from the upper left corner of the, G9 t1 O; V6 C! z% l
;; world. -1 for non-intersection patches.
. K/ ]; S9 Q3 A, V+ x- s! [& O, o. m my-phase ;; the phase for the intersection. -1 for non-intersection patches.* O0 r6 R' X' f4 p4 C# h' {( K
auto? ;; whether or not this intersection will switch automatically.
' \1 d& [4 X- S9 P4 s/ f3 ? ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;' i6 |9 ?! e" @; U4 j/ }. v: ^- S
;; Setup Procedures ;;7 o# s3 K6 v8 P; A( Z
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
3 ]- u6 r% y* K% c0 z+ z, H;; Create num-cars of turtles if there are enough road patches for one turtle to
3 y E! w+ b) ]4 Z;; be created per road patch. Set up the plots.3 Y6 S( A M7 V' P2 Z5 F
to setup
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4 ]+ ?$ J! k% K, `- O/ ~ setup-globals" J; z# O; a3 ~/ B5 m: g! O
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;; First we ask the patches to draw themselves and set up a few variables
% c/ C; ~1 ~7 O7 H5 v setup-patches
$ O R3 s8 q: V6 O$ \ make-current one-of intersections
/ h* q* \$ z6 s, ^% v* o1 y7 i" Y label-current; H; ^0 X0 L& C: ^; ?9 c9 S3 D
, U+ z$ }- E& E/ w5 h D set-default-shape turtles "car"
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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 "& |/ w4 S* x' y3 v* Q& y
"road. Either increase the amount of roads "
& r; @" S$ u: M3 B% A p8 g8 @ "by increasing the GRID-SIZE-X or "
! d, C2 Q* _7 @* ]4 j2 M, Q1 _) f4 a "GRID-SIZE-Y sliders, or decrease the "
# o, S T3 o- o b" n% k "number of cars by lowering the NUMBER slider.\n"
- H. E; ?- Z. f e "The setup has stopped.")! d% L0 _" \8 q/ P3 ^2 P
stop5 _- @# b5 q+ N* T+ `
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color# |( U" g7 b9 ^8 j* [' A
crt num-cars3 k# W# i* t5 I( ?4 ^2 ] l: ^
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1 _9 A) P" z: S: t2 P8 W" k setup-cars' V! G. b: ~: W+ L1 _" L7 t
set-car-color- @* U6 H7 i2 X# t4 f/ i
record-data
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+ c: {0 X" L1 Q# A2 ^; @5 a9 w ;; give the turtles an initial speed
5 f- q: S7 ?* s$ W, C* d h5 e, R R ask turtles [ set-car-speed ]
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reset-ticks
" j1 d" T5 Z+ f: A7 S- uend
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7 `! I$ b4 c( g! |4 B1 E# J;; Initialize the global variables to appropriate values
5 C$ f7 A# C2 v1 N# cto setup-globals" r+ \0 {0 O9 e$ V3 N
set current-light nobody ;; just for now, since there are no lights yet+ Y: t! H9 | n- u6 J1 Z$ t' O
set phase 0
- B0 t A# ^9 U+ H0 p- w0 O! y; x set num-cars-stopped 0
! m% t- @3 r' N6 T8 X set grid-x-inc world-width / grid-size-x
8 l0 v* y% @4 Z set grid-y-inc world-height / grid-size-y9 I! ]; `+ h3 d* H% O7 U8 `7 d* \
; k- ` M6 w) u4 h C% [3 V5 K9 _ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
6 ?# n/ n/ J% c$ G& A- i0 F" M set acceleration 0.099
8 V/ d9 j8 L* A- j6 R+ ~, Uend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,5 e- [2 e5 _$ O" S" i% R7 A$ m
;; and initialize the traffic lights to one setting
9 L4 P$ ], t" t8 C( p4 dto setup-patches& J) }5 o& ~! `- X
;; initialize the patch-owned variables and color the patches to a base-color
- O4 Z& }& f8 T0 O! d/ j! X( N6 P ask patches
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set intersection? false, Z/ s1 L, a7 k7 ^
set auto? false/ V) L$ |& Q& t
set green-light-up? true$ l4 e: ]6 f7 K2 H7 Q, ^# H1 h
set my-row -1. O) X9 K# P, ]
set my-column -1) G7 B7 R+ Z/ b) d ?5 {
set my-phase -1
* q: L* e f3 \/ _0 \ set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
. @, x# Z. P P2 C" D5 I) ` set roads patches with' k' L; s# O1 S3 E0 `
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, f2 N4 W M- Z* ]3 F9 q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ O1 W9 ?' z+ C: [/ C1 I; P set intersections roads with
* X. r! ?. u0 G3 {5 i! t [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 Y* W3 a: ?1 g7 R* h (floor((pycor + max-pycor) mod grid-y-inc) = 0)]! I; W+ Q4 f7 u) n2 y9 J
& |" c" g# b3 h7 ?+ S ask roads [ set pcolor white ]0 F9 \- a9 h; A7 o
setup-intersections I5 w6 x; R% Y# U8 e* a$ o
end& x5 v: b" C; g9 J$ Q9 U: O! n
其中定义道路的句子,如下所示,是什么意思啊?
! F/ p' y) q1 h# O) f. _+ A set roads patches with
7 Q( w0 P1 Z4 w6 y2 s" p) c2 R [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 i, h' q- `6 O7 @1 l
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 Q# [9 M0 Z6 B$ y7 a0 G) 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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