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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。
" ~+ e- d; M7 Inetlogo自带的social science--traffic grid这一例子当中,
: M/ }* B- d/ i# f2 k, J/ qglobals
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7 L/ w5 [* O, f: \* T grid-x-inc ;; the amount of patches in between two roads in the x direction8 ~/ g7 @0 F% R' v3 ~( H- v
grid-y-inc ;; the amount of patches in between two roads in the y direction
4 N. Z9 o R8 e) e9 L) o4 B acceleration ;; the constant that controls how much a car speeds up or slows down by if/ _1 ~1 s- i0 h: s. f Z
;; it is to accelerate or decelerate( M: ^: g* a- `0 }3 z
phase ;; keeps track of the phase
+ `, K# b& Z( w% y& O( s4 H4 W1 ]+ c num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
" v8 \! @; c& m: \) p current-light ;; the currently selected light
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;; patch agentsets
( E$ d3 x" h( g7 u* B' c% x# F9 |, P intersections ;; agentset containing the patches that are intersections
$ q/ R! u4 U( x F- K roads ;; agentset containing the patches that are roads
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turtles-own. O3 |8 s' X( ]8 ^7 p) G9 @$ u
[
, f" N9 N+ `* \ speed ;; the speed of the turtle, B( Y( \: J# N7 Z
up-car? ;; true if the turtle moves downwards and false if it moves to the right
# g ?' ]8 a4 @ wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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7 B s J5 _. U4 j intersection? ;; true if the patch is at the intersection of two roads
' {3 r1 A2 W: ?& P' X9 X- y8 @/ _ green-light-up? ;; true if the green light is above the intersection. otherwise, false.' K j' Y1 B) v" K
;; false for a non-intersection patches.2 }6 j( ~" c0 ^' A
my-row ;; the row of the intersection counting from the upper left corner of the5 D, Y; B* k3 U7 {; q
;; world. -1 for non-intersection patches.
0 z4 w' s. x S, c my-column ;; the column of the intersection counting from the upper left corner of the# P1 E7 u$ X. [* E! K! `/ l! U
;; world. -1 for non-intersection patches.
" A B1 ?% C9 M2 D my-phase ;; the phase for the intersection. -1 for non-intersection patches.
, ?, i1 L3 K- P9 y auto? ;; whether or not this intersection will switch automatically.
0 r5 Y7 Y# q$ O ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
) o6 j. v7 e& m4 I! H5 S* q;; Setup Procedures ;;# s7 q4 W) ^- N: _
;;;;;;;;;;;;;;;;;;;;;;, X& {: n. b8 }4 ]% c8 Y
]& z7 h5 M4 b c;; Initialize the display by giving the global and patch variables initial values.2 v& Y. @! Y1 V V& u
;; Create num-cars of turtles if there are enough road patches for one turtle to
: {# A/ b6 ~7 X/ ^4 H+ a;; be created per road patch. Set up the plots.( y5 F3 t z& a
to setup) F2 `) j7 j, B- r
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setup-globals
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9 h1 L8 h3 y6 y+ l3 S ;; First we ask the patches to draw themselves and set up a few variables
5 R3 r' ?5 j5 W setup-patches1 }; r) [! V1 V0 c D. X
make-current one-of intersections8 F7 w. K! W/ _" z
label-current
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set-default-shape turtles "car"
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; C: }2 n# z8 K if (num-cars > count roads)
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: G X1 P, M9 o+ Y& f+ {/ ?# o user-message (word "There are too many cars for the amount of "
2 g; N. L9 M" T/ m "road. Either increase the amount of roads "
2 o8 R& W# S9 a- H; f& T$ i9 n "by increasing the GRID-SIZE-X or "8 L' k- r0 o& O1 D7 X- |
"GRID-SIZE-Y sliders, or decrease the "* e+ ~2 q* V$ J+ e% |
"number of cars by lowering the NUMBER slider.\n"
$ [' i) e$ e. J. V4 \0 c$ { "The setup has stopped.")& @/ v- N* `2 t" a# Y, H8 m& y
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# }- n4 d* O& v$ `; t, ? crt num-cars
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- S2 c- ?8 V& k( N2 I2 q# b setup-cars" `5 ?. m# _6 b& [1 t1 g9 u
set-car-color) l6 G% a/ X$ f* E% n) B+ L' _
record-data
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7 d# n9 B1 X1 k" E/ x ;; give the turtles an initial speed
- D9 h H# C$ h8 | ask turtles [ set-car-speed ]
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reset-ticks
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;; Initialize the global variables to appropriate values
4 h+ N0 R! k; o0 ]to setup-globals
- H% c7 b7 F( L$ I9 j! B% x X set current-light nobody ;; just for now, since there are no lights yet
1 d7 f# t8 ~) T" r; W% @& a set phase 0- e$ j5 c" ~) y" z' d( q9 f
set num-cars-stopped 0
+ O8 v0 v8 h: R; z" J- { set grid-x-inc world-width / grid-size-x1 S; m3 S5 h* g ]
set grid-y-inc world-height / grid-size-y: d; w. d2 ?6 j
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary( t- w+ W6 b* _6 f0 J/ Q7 }
set acceleration 0.0998 Z+ y+ `8 {: b
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
- I3 n5 e% y" q: l! W;; and initialize the traffic lights to one setting
0 P4 w0 z c. J9 G9 i- ]to setup-patches
; z% \# b4 N/ j! [1 U% R: o ;; initialize the patch-owned variables and color the patches to a base-color
3 y- K- C; V' A ask patches
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+ m3 z& ^5 O& j: ^9 G p1 A8 V; w set intersection? false) L& H. g0 a, I0 Z; M3 k
set auto? false
3 S+ `$ L c3 G: X$ R' h5 h8 X set green-light-up? true, F: ^) A1 z- T2 k$ {# I+ G/ _
set my-row -1$ c: H8 c! e v0 B: }: c1 C
set my-column -12 z9 k. k+ ~+ D; g& v8 N$ `( o, J
set my-phase -1
) ^0 @. l, j6 P& D* s6 y9 l) B1 F set pcolor brown + 3) I6 Q( o. |- |. u% k! [) J
]
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;; initialize the global variables that hold patch agentsets0 f; t& k7 a* B# c# R! w5 w
set roads patches with
5 u; B6 O/ d d+ T- j# M4 @9 V [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 y$ P2 Z+ |7 L6 i7 X1 V1 |& R (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
4 K' T4 x' k+ b9 {+ z set intersections roads with, u( K! E Z: t8 K: h
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and1 W5 h. K" n: i) a( t% m5 s
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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2 R4 p8 l/ f H, b( n ask roads [ set pcolor white ]
6 N* D9 C& ~7 ?- s) i; r* c3 d3 } setup-intersections8 T1 |, J! G8 X# W& f; ~
end0 T' N( V; g; F b
其中定义道路的句子,如下所示,是什么意思啊?
" r# H8 q7 w% y1 @9 D! ?" o5 [. m set roads patches with
/ j% g- j0 M) o! f. B [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" v6 W* V5 ]" B5 L! u5 Y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ X. ^& P, h. L5 i. M
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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