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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 d4 r6 |6 H9 x6 L9 m7 E; a
netlogo自带的social science--traffic grid这一例子当中,
. i* e. p8 r4 i8 r7 l8 rglobals
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1 C3 @6 q' F) W7 a+ X grid-x-inc ;; the amount of patches in between two roads in the x direction
" T! O3 s s: m# C grid-y-inc ;; the amount of patches in between two roads in the y direction$ o: `( Z Q" G4 y, ?) Q! o
acceleration ;; the constant that controls how much a car speeds up or slows down by if
* D" b: h, E7 g6 U# T# M ;; it is to accelerate or decelerate0 H9 I# e' m( r: ?2 G( L
phase ;; keeps track of the phase
* ^) n, Z: n' d4 W, Q0 L0 d num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
6 u/ k( F# L% D; `+ w current-light ;; the currently selected light
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;; patch agentsets( d6 y5 a4 `4 G U2 E
intersections ;; agentset containing the patches that are intersections
5 [; ?$ r, U! R$ h% r roads ;; agentset containing the patches that are roads
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- T; z# d5 T* d, m( F& W3 X9 bturtles-own$ c* h* o! [" S+ S
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speed ;; the speed of the turtle
v5 w( P/ t' w O2 c up-car? ;; true if the turtle moves downwards and false if it moves to the right
- @/ x% g/ Y/ E# J! K' A' }1 c7 K* R wait-time ;; the amount of time since the last time a turtle has moved
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$ q& R: L( H8 I- H( O# I" hpatches-own
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intersection? ;; true if the patch is at the intersection of two roads% a, A' ^3 \% ^5 t7 z! `+ i1 D
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
. g. l$ [9 C+ x8 B# { ;; false for a non-intersection patches.) U+ u( [5 n' K, @ `2 B2 v/ i
my-row ;; the row of the intersection counting from the upper left corner of the& T# A, g [- ?+ e- j
;; world. -1 for non-intersection patches.7 F! f+ I3 x! j5 E. X- s4 x: H, p
my-column ;; the column of the intersection counting from the upper left corner of the
: W) v6 u/ N1 m/ L ;; world. -1 for non-intersection patches.
- r4 t; p3 k0 |# }7 i) o my-phase ;; the phase for the intersection. -1 for non-intersection patches.
9 J& P$ K9 l9 R4 ~0 k6 L) `6 S* H auto? ;; whether or not this intersection will switch automatically.
: I& @& x3 q0 W( g/ v9 V! C. ~ ;; false for non-intersection patches.
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7 J' z% X, A# ]+ H0 r3 R; n7 s( k/ R;;;;;;;;;;;;;;;;;;;;;;
2 ~; U6 r! `6 L/ A3 r5 W1 h3 [* @) t$ [;; Setup Procedures ;;7 ?0 t% ]. c Z2 a8 `, `6 e8 c
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
" H9 X7 X+ A: j1 h) U' H$ g;; Create num-cars of turtles if there are enough road patches for one turtle to2 E* o2 E( h1 v6 g7 e
;; be created per road patch. Set up the plots.
2 \, Q" {4 U6 ^) R. Pto 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) [: q8 R* B1 j# v
setup-patches
: F# q' z5 K% E$ A1 w0 L3 j make-current one-of intersections; {2 A# M4 c( c1 n: p" T1 Y
label-current
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set-default-shape turtles "car" ^& N7 g$ ~' m4 t3 ]/ y3 X
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if (num-cars > count roads)( m8 k) y1 k1 [/ J& X5 [8 ?
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user-message (word "There are too many cars for the amount of "/ S2 Y' d, T9 r# D4 n9 O3 ~
"road. Either increase the amount of roads "* F; Q. ?9 n2 G3 r
"by increasing the GRID-SIZE-X or "# ~! ]" V P! P, o0 J) |) d1 F
"GRID-SIZE-Y sliders, or decrease the "
h1 B, w5 t% d8 p/ T2 k( X5 c2 ] "number of cars by lowering the NUMBER slider.\n"
2 v9 G7 [* H, I+ J, W "The setup has stopped.")
8 K, @5 a8 z7 q& }; q stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color' ?. Z$ l( U" m
crt num-cars
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setup-cars/ u* _/ K! X$ j) u6 ^5 N
set-car-color E. m% P5 S+ v2 f( \7 T
record-data7 ]$ @9 c# g0 b( H: o
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;; give the turtles an initial speed
. G; l& [0 f7 O4 P% u ask turtles [ set-car-speed ]9 U3 d: e% i1 M4 b
3 t) u6 ? t0 d( B1 \$ a; g reset-ticks
# B8 x: I' [" h' `( N* ]1 _9 Pend- t' {: C& @! Q
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;; Initialize the global variables to appropriate values
& }3 W% j1 i; H5 w4 rto setup-globals
6 q6 W) [) p2 L) R4 @! v set current-light nobody ;; just for now, since there are no lights yet3 g; b; p3 q' H
set phase 0# g4 R3 q7 }3 ~5 J+ X
set num-cars-stopped 0
) T/ @4 W) Y0 v2 {, h set grid-x-inc world-width / grid-size-x2 W5 M9 w- v4 v
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 boundary0 g ]/ }2 X) H9 H1 C* s
set acceleration 0.0998 x! |$ }% M- e! R3 ~7 i
end" v5 X( v2 o6 Q) R% u7 E
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
7 W$ J5 K" t2 P' |7 u;; and initialize the traffic lights to one setting% D$ C" r& N. A0 w! \: T- F
to setup-patches
( h% u8 R2 H0 b& Z0 \* z ;; initialize the patch-owned variables and color the patches to a base-color
8 `: Z: r! V2 `7 i ask patches
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4 B0 M# A" J# q& w set intersection? false
" ^0 k; R1 r- k8 b- b set auto? false
. h6 I9 r9 g1 H0 b set green-light-up? true
. J1 B. t- A' D# b set my-row -15 t1 e* Z3 s, z5 }
set my-column -1
2 |+ E. S9 c$ M6 R. H3 Z set my-phase -1
4 O# Y4 U! s) x" n1 M set pcolor brown + 33 o8 d' X* }5 [1 k4 u
]
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6 j! D2 |- b- ^9 ]! P ;; initialize the global variables that hold patch agentsets7 Z5 ^) O( ~9 x0 M7 H4 r
set roads patches with$ \& u/ w) M+ `* U, m x. n
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ }1 s$ d# @6 _3 M! ?/ { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' N# @. P9 g3 b% e
set intersections roads with
8 `; |3 {% @1 Q) S# n [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and2 F) S3 c; e/ b6 y$ v* S$ t
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]& Y$ V# \$ o* \# L0 m5 z. W
+ c/ r) P) ?# F; f; B ask roads [ set pcolor white ]
- U# \& i v; z- ]7 ]2 ^0 p setup-intersections
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0 A+ C5 J. L8 X; n& L1 F' b2 \其中定义道路的句子,如下所示,是什么意思啊?
9 M! j( z! g+ I9 i4 g, s set roads patches with
& [, E4 @: l# Q1 G6 | [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ a! y% H# j0 [1 M1 x
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 A& i! l! X" I+ a$ e0 X
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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