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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。
/ x: x! g9 m. k" p' ]$ u3 Vnetlogo自带的social science--traffic grid这一例子当中,
+ I2 S1 l+ Z1 [, [" Cglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction! ]8 H! \' T6 {3 J2 l$ U* S
grid-y-inc ;; the amount of patches in between two roads in the y direction5 u4 S4 o% {/ n$ @3 H
acceleration ;; the constant that controls how much a car speeds up or slows down by if
& D% O1 M+ S) C! b ;; it is to accelerate or decelerate8 m D" v! ]5 O$ u% [; f* K5 a
phase ;; keeps track of the phase
! w- y; ~8 j# h" V- D1 d0 ~3 x+ b num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure9 a' N& K" R: L, ?2 W4 X" Q
current-light ;; the currently selected light8 m L/ e0 C L- G; @) n0 Z
# l/ M o+ ?& O0 T8 M2 D ;; patch agentsets' ^; a) y( l- [2 O5 h( V8 t
intersections ;; agentset containing the patches that are intersections& h7 V% [& y- Z" k
roads ;; agentset containing the patches that are roads: i: q4 y, R: ^0 k" h9 {) {7 c! J
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2 m0 {+ l9 r) j- [1 @# Mturtles-own
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|7 b# \* i7 V' h speed ;; the speed of the turtle! z6 v/ Z. r1 v) a3 M
up-car? ;; true if the turtle moves downwards and false if it moves to the right4 Y8 f8 D" @4 ]- E6 m1 A
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own. Y7 Q6 @. q. x2 u
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9 c: u! K& t: x9 \ intersection? ;; true if the patch is at the intersection of two roads
# G2 B/ D9 z, H [+ V7 W$ y green-light-up? ;; true if the green light is above the intersection. otherwise, false.8 B3 x; B# c9 E9 T R
;; false for a non-intersection patches.
( R5 N9 U3 D. ?* d5 ^- r my-row ;; the row of the intersection counting from the upper left corner of the* { Y. p+ u- {, x4 t2 |8 o- G; P
;; world. -1 for non-intersection patches.
1 s2 _, o+ o. G my-column ;; the column of the intersection counting from the upper left corner of the
# }+ `) q' d! d. a% t- w$ K$ ?3 ` ;; world. -1 for non-intersection patches.
+ _+ X* ~0 h1 { g0 [% v my-phase ;; the phase for the intersection. -1 for non-intersection patches.4 m- f# Y t2 z# n
auto? ;; whether or not this intersection will switch automatically.' C) P- P7 @/ x( ~/ p
;; false for non-intersection patches.' [' y- g5 I n+ F3 v9 e7 r
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0 d' Z* c) i, s1 i* r7 H L;;;;;;;;;;;;;;;;;;;;;;
) _. K! a0 ?$ P8 M;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.1 h% U2 {: f5 U5 }+ f9 a- i0 A) m
;; Create num-cars of turtles if there are enough road patches for one turtle to
6 ], q1 r( s# e. j;; be created per road patch. Set up the plots.
/ N( U5 t! i* @* o! U' r9 mto setup
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setup-globals) j8 C. I/ Z8 c* v
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;; First we ask the patches to draw themselves and set up a few variables
8 p+ q4 ~2 m5 l9 K setup-patches
6 }& k& ~+ d2 m% I8 w: R/ K: T make-current one-of intersections
! w. P4 g" m. }# L label-current; J" ]- C0 ]0 x! s& K, f- D
; d0 v4 G* A7 `1 c. R1 D. | set-default-shape turtles "car"% G" x4 o5 x4 y3 g
! {2 Z8 V, F2 w7 s; ?, O if (num-cars > count roads)" Y: I/ H9 m# \! D
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1 B1 H6 p$ D+ I0 ` user-message (word "There are too many cars for the amount of "3 B, s4 r9 h" u
"road. Either increase the amount of roads "
]0 `+ M, J: Z7 B- ^0 Y "by increasing the GRID-SIZE-X or "2 K0 U! a$ [0 D
"GRID-SIZE-Y sliders, or decrease the "
8 I! N# B& |, {8 a "number of cars by lowering the NUMBER slider.\n"# Y5 M4 p& u1 M5 u( {2 k3 W# M. M& }
"The setup has stopped.")
% j5 ]4 h4 Q! E6 s+ Q stop
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7 i$ y; ^2 g) }; n ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
. E2 i; D% C h9 t" ~+ B; }4 G crt num-cars
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setup-cars
\4 |$ |& G* V- y set-car-color
& ]) F3 i# R( U: Z record-data+ F" r7 j, x0 s: H: N' j" P7 h
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;; give the turtles an initial speed
8 c3 o6 V! h5 S# B) r ask turtles [ set-car-speed ]
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reset-ticks
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; y) T Q* x$ p1 _/ b* h9 ^# {;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet: v& i _ g, c
set phase 0+ g5 O# r/ f* L7 W z
set num-cars-stopped 0
, E( J/ ?4 Y+ \ set grid-x-inc world-width / grid-size-x
/ N3 ?+ m" F& W4 H! x4 J set grid-y-inc world-height / grid-size-y4 V1 T1 g/ a8 ?1 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+ x7 L- o( W# ~+ t7 e8 s6 z* H% D# C
set acceleration 0.0991 @/ K. j* ~; J% b+ q9 ?6 E; M
end
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3 w6 d4 E& o; Q;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
+ W0 N/ x& i/ s1 i/ c: e;; and initialize the traffic lights to one setting
: H( }! Y% k9 x& e4 n+ H3 `$ Vto setup-patches
4 F( K+ W/ ~3 |" T ;; initialize the patch-owned variables and color the patches to a base-color# n" P( H) w w# U" i% u; }) L
ask patches* M5 s+ _" u, u+ R: b1 b
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% k2 |4 R* {2 J1 S% w set intersection? false+ c7 I- k( B4 Y) u- p
set auto? false& E3 t X$ [4 N
set green-light-up? true
7 \$ D* g1 q& O' f9 l7 c# f. ? set my-row -1
( C7 u5 l/ l* J- J1 R. g5 k3 n, m set my-column -18 b& s( }$ t4 a% Z2 q3 E4 [
set my-phase -1
& _$ I% m! ?# e% V3 y2 q+ H set pcolor brown + 3; A% i/ r$ |4 e
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1 O- I: N( u7 l( x. | ;; initialize the global variables that hold patch agentsets
) c5 A% W7 q8 s5 l& c- o3 ~ set roads patches with
2 `- X+ F$ F& n* g- [" T8 G/ L [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% L8 @; Z0 @# k- e! b' `
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: e: R- e2 v, }& J set intersections roads with1 A9 s$ E1 ^8 ~. a: j
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
% Q1 s7 f" \6 t7 W9 m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 w. {" d/ t! \( s
- s$ Z. Z: m7 j, |! T+ o- ]* ] ask roads [ set pcolor white ]+ j2 [' X: L1 V, M
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?
9 r3 m$ C% Y' j. E* T4 s set roads patches with+ \! n$ r: Q$ T( d7 L1 ~# i
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 |1 t. n% E9 l! f; |" w- {& F
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]# ?4 n5 t0 k/ ? 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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