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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。" C/ b ~) y6 r1 K8 e4 }! T
netlogo自带的social science--traffic grid这一例子当中,
) [8 F# L& o: k) f3 O- [7 ]% pglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
7 P1 l( ~" d$ f! _/ ^! H$ X. G0 _ grid-y-inc ;; the amount of patches in between two roads in the y direction
8 a. r. m2 {6 w. e i acceleration ;; the constant that controls how much a car speeds up or slows down by if
V) w# V) T1 D. L! v ;; it is to accelerate or decelerate
0 c/ d4 @1 f$ _) S- ]5 x( u/ m. ? phase ;; keeps track of the phase
2 D% p" }6 X9 _( ?" |7 W9 _6 z num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
" Z, O. s. W. p; _7 u current-light ;; the currently selected light
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- x# K8 w) h7 v ;; patch agentsets" {# @0 X3 f% t6 Y, [ s9 M5 j3 l
intersections ;; agentset containing the patches that are intersections- R9 I$ F3 y% W' [; c4 r0 w
roads ;; agentset containing the patches that are roads3 k1 P5 L5 U& i
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turtles-own+ a9 y/ j. W0 S( i, s3 ~. g# E1 K" d
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speed ;; the speed of the turtle$ d, o+ k* ]! b( w$ O ^1 ]( ]4 W, U
up-car? ;; true if the turtle moves downwards and false if it moves to the right
9 K) m1 q$ s$ ?- | wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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! s" p9 E8 ^, X% k intersection? ;; true if the patch is at the intersection of two roads
$ |/ Q9 r; ^$ m# x, Z5 p" I) Y! I green-light-up? ;; true if the green light is above the intersection. otherwise, false.7 i, s2 m/ Y; h& G! M3 D) {
;; false for a non-intersection patches.
3 Y( a7 s% [$ f E2 |. e my-row ;; the row of the intersection counting from the upper left corner of the
: f# }8 n5 z7 B7 h0 S ;; world. -1 for non-intersection patches.
0 X- i) v8 s5 C. o my-column ;; the column of the intersection counting from the upper left corner of the
8 G1 }+ }# m, } ` ;; world. -1 for non-intersection patches.: @7 h/ d% N2 F1 I# U( v" x3 n
my-phase ;; the phase for the intersection. -1 for non-intersection patches.6 A' S7 T, p5 p$ ^6 K! G' c2 W
auto? ;; whether or not this intersection will switch automatically.
# T8 B2 N- G" J. w2 z8 X d# J, a ;; false for non-intersection patches.; u1 u# Q0 Y. I- P8 x0 J% W
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( z- @# z+ M" C" \/ B;;;;;;;;;;;;;;;;;;;;;;
( w/ J4 ?2 b1 R8 W; B1 }- C; G;; Setup Procedures ;;
6 d" x. |9 x1 q6 \/ J2 U7 E;;;;;;;;;;;;;;;;;;;;;;4 W( l2 c7 w5 w4 k L+ T. _
7 X& |$ c' J* K5 b5 K;; Initialize the display by giving the global and patch variables initial values.- f) D% i. K6 }8 @* Z
;; Create num-cars of turtles if there are enough road patches for one turtle to9 T3 z& O8 I* R0 t" V+ d
;; be created per road patch. Set up the plots.- u+ s( y+ j* ?: J/ e9 Y9 B, r. c
to setup& y8 {8 c) E9 g
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setup-globals
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; ?4 C* e$ w8 k4 \8 n( ^ ;; First we ask the patches to draw themselves and set up a few variables+ A5 p. s- ~5 a$ N; B, Y
setup-patches, M/ k' f+ w* ~
make-current one-of intersections
% L8 D" O3 k( H: I7 e1 F. d label-current
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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 "% U1 @/ T- G5 G7 q# r J0 t8 ?
"road. Either increase the amount of roads "
/ ^; L- S3 P( a& s3 I. i/ A5 m "by increasing the GRID-SIZE-X or "+ ?0 f: @! e8 D2 m* |. ]
"GRID-SIZE-Y sliders, or decrease the "9 M5 Q: U9 E+ [/ g( r0 Y$ K. m
"number of cars by lowering the NUMBER slider.\n"( |) h v% I& P5 w
"The setup has stopped.")8 @$ C% R) G2 v
stop# J& A9 l& U+ R1 E! h
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color* B$ f* `4 e, r- }3 X' Q
crt num-cars
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setup-cars
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record-data
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;; give the turtles an initial speed7 a- _, h7 z3 {7 I- b
ask turtles [ set-car-speed ]% v% b! a" n' z5 i& t' I
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reset-ticks
; z1 E) Y( T0 E0 T" ?end- f$ y/ ~+ U' W5 R" e; D
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet, \8 _' s: ?' f' k/ z2 a1 ^9 X
set phase 01 g7 F$ ?* c O' _' f2 u9 t
set num-cars-stopped 0
# v9 Y* L) q3 t7 Y set grid-x-inc world-width / grid-size-x
4 S; a: f, @' \+ e1 X' C- t; s set grid-y-inc world-height / grid-size-y
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0 N7 W9 ^& p O2 C' b ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary7 C6 p$ ?- U# Y# z! _
set acceleration 0.0991 g5 }5 q# i( p" `
end
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% u" r L# P9 Z# X9 L;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
, T+ J4 m, A) ]: Z, e0 m" x0 r;; and initialize the traffic lights to one setting- j3 Y+ h0 i& F/ `3 I8 O) F; W
to setup-patches2 r1 g/ m) G3 O2 l- _
;; initialize the patch-owned variables and color the patches to a base-color% Q) e- y9 G9 m" R$ S& |* E/ f
ask patches
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set intersection? false
' h" X n; O9 W8 ? set auto? false
! O3 R6 `+ x0 q$ L7 L4 u2 o& t set green-light-up? true
; n Q8 @* Y* J$ o set my-row -1
. {. _- }$ b3 z, S# p set my-column -1! F# n4 U3 O* N( F7 o2 ~
set my-phase -1
+ h0 b& ?$ J8 \( k& r* N& L6 v set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets5 k+ Y) Q7 e q; ]
set roads patches with
% n5 G- V& N$ w3 H1 H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" [% {3 y7 e! Y$ H* K n' o6 q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 R+ ]3 ]7 o4 P J% O1 Q* k set intersections roads with
% o( P( H, W' J) I& g Q$ \ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
: y$ Z, Z9 J+ Y- Y. b (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& B$ l2 H$ k/ `& J4 u8 v7 `8 b
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ask roads [ set pcolor white ]
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5 W' X' b! ~- D# i# |8 L其中定义道路的句子,如下所示,是什么意思啊?
' G0 I5 y v2 x1 {$ e set roads patches with
; {7 i% [: _6 z; S+ [5 Z* p [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 N2 s# S9 M/ N/ C9 C3 O
(floor((pycor + max-pycor) mod grid-y-inc) = 0)] j7 o+ k4 n; @% P A
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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