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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。% b# `6 Z) w W, M' B( J# N- q E
netlogo自带的social science--traffic grid这一例子当中,3 M( P* C3 L1 A* |1 }1 D2 u' y7 M
globals6 c. w# T/ l" J6 v% Y
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6 _" U) V& i5 G" {: L: w8 ]4 u grid-x-inc ;; the amount of patches in between two roads in the x direction
1 C( q# H3 q6 W/ Z2 G, u grid-y-inc ;; the amount of patches in between two roads in the y direction
. O# @6 \9 |6 Q. x' u acceleration ;; the constant that controls how much a car speeds up or slows down by if* U& M m0 J, F
;; it is to accelerate or decelerate
) M0 L; E/ D2 c m: c phase ;; keeps track of the phase
+ ^0 ]! \7 K+ D& S' p; @ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
- h( ]6 n& R% T: ?; q# l2 V+ l& ~ current-light ;; the currently selected light6 V2 f7 O+ ?5 C9 e* Z6 n
" D l) t Z4 C) _" Y, g/ }, j2 A ;; patch agentsets r# { i1 T) H- s
intersections ;; agentset containing the patches that are intersections
) U* h l' i) Z* ~ roads ;; agentset containing the patches that are roads
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3 c k5 Z+ C1 B7 {( E5 J, Nturtles-own
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speed ;; the speed of the turtle- S. _5 ~0 Q3 p* t4 K
up-car? ;; true if the turtle moves downwards and false if it moves to the right
6 L; P3 u6 q1 l/ V wait-time ;; the amount of time since the last time a turtle has moved) b3 r+ I- g( I# l
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8 Y0 S5 T% F% q& k) s6 Opatches-own) a1 T: t& N5 K$ ~! G
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intersection? ;; true if the patch is at the intersection of two roads
2 z! v( u7 E! ^: s- f green-light-up? ;; true if the green light is above the intersection. otherwise, false.: t Z$ k5 A' ]# N4 j) h2 M
;; false for a non-intersection patches.: O1 }! J9 o3 Q
my-row ;; the row of the intersection counting from the upper left corner of the
$ I! z8 v& z) T1 S ;; world. -1 for non-intersection patches.
% W$ x/ C" }% f% Y# J% P my-column ;; the column of the intersection counting from the upper left corner of the$ P7 w" f; @. f- K) s- J; H: ]
;; world. -1 for non-intersection patches.3 @$ X% l( D( ]) t" y! K; k
my-phase ;; the phase for the intersection. -1 for non-intersection patches.$ f$ U4 ^, c0 J# e2 q
auto? ;; whether or not this intersection will switch automatically.
' ?% Z* f5 t" l$ A ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
s" F4 C" X8 e& B) H4 {2 f;; Setup Procedures ;;, J. W. C4 L6 L
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
' M! @8 U# ]& l: y- S; l;; Create num-cars of turtles if there are enough road patches for one turtle to
) {7 ]' N( N$ x A8 n/ q3 e;; be created per road patch. Set up the plots.$ ?! }+ P/ O9 r/ |0 P6 Q, x
to setup* M* S) {5 T6 x7 e; ^
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setup-globals
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7 t) r% z7 [% Y3 S2 C1 i- D ;; First we ask the patches to draw themselves and set up a few variables# _5 f9 o, m+ ^( {( N5 [6 H
setup-patches) b7 y" S0 Y( q& n: `& q' f
make-current one-of intersections' d2 W1 z' T" |3 n
label-current
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8 T0 p& H$ z6 ]- a0 X# c set-default-shape turtles "car"# ]% }- _8 ~+ Q- R0 V
) |: r/ s& N( |; ^0 l& Z if (num-cars > count roads)* V3 Q! N. ~# _
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. k! w _7 S, d8 p8 T user-message (word "There are too many cars for the amount of "
1 U+ `7 H" L$ `! W6 _ "road. Either increase the amount of roads "
! W) O$ p" W o M- l "by increasing the GRID-SIZE-X or "2 q9 ]# D! Q3 B# V! w
"GRID-SIZE-Y sliders, or decrease the "( J# T0 ]4 ^$ m
"number of cars by lowering the NUMBER slider.\n"
8 N, M* q/ g1 Y "The setup has stopped.")
+ j9 J& ]( q2 r- O stop" u! f+ L; p2 j- R) j' M
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color/ V+ U: j$ m d; }+ K7 k: m9 d( q
crt num-cars- H2 g# ?7 m. Y: q# @
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/ ?/ `) V$ M# A1 m: @+ X/ Z/ T setup-cars( U) ^# O$ z$ b7 ]' E8 V
set-car-color
& ~6 m" b5 `' i' G3 e: O record-data0 q/ g; d' }( L' E; i
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;; give the turtles an initial speed
* ?/ B: Z& y. Q2 M) i4 b ask turtles [ set-car-speed ]3 F9 f4 f8 _$ `$ ?. f, T4 _8 b# @3 T
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reset-ticks
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; ~) A! H6 B/ u# X;; Initialize the global variables to appropriate values; S& C) U" ^" ]$ h0 T) C& ~
to setup-globals- y% o/ V* \& Y7 x
set current-light nobody ;; just for now, since there are no lights yet4 E" O p2 r. o8 `! ] X! l
set phase 0$ \$ i. ~( R5 d2 ~+ I" |) S$ o
set num-cars-stopped 08 ?9 F/ u0 A; Z6 z3 h
set grid-x-inc world-width / grid-size-x
, L# u" I6 q8 b4 u0 {, I8 F/ ?3 Q set grid-y-inc world-height / grid-size-y1 G- x4 T( X$ I; M, z+ 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
# r' f: I6 Y3 @0 _/ ~, e# M7 B set acceleration 0.099$ C6 Z( S0 G% X
end7 n; Z! X1 y2 n
( f4 J0 v) Z+ m1 O, U: L0 D;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
4 _9 U) K/ u% Z3 h;; and initialize the traffic lights to one setting
' |- Q; t9 O) m: t8 ]to setup-patches
8 Z; M: D5 b6 {) w/ |) O' s ;; initialize the patch-owned variables and color the patches to a base-color# H4 h7 X' h$ n5 H0 l1 X! j
ask patches
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set intersection? false
1 G2 ^' N' S# ?+ ]7 ` set auto? false* _' ~. i9 o3 w( j
set green-light-up? true) Y, F7 c j, n4 X( O2 _
set my-row -1
8 e3 O5 T1 e+ @, B% v. z( k2 s% Z! J set my-column -1! f+ v/ r, ^% v0 g @& a5 m
set my-phase -1
2 b5 E% a. k" v set pcolor brown + 3# ?* T* c; @6 n
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;; initialize the global variables that hold patch agentsets* z- M' A z2 W# a( ~. m5 Z
set roads patches with" \9 m4 K& C" l. z1 X
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ o3 o7 N; A& V4 n Q+ x7 y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 N! D8 Z7 k& K
set intersections roads with
9 y' R9 G; |" W1 s' [( P [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and- v& m4 U ~1 l+ C. ~9 A- g X
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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+ P( g; F, T) {- C9 V% {& H. ~ ask roads [ set pcolor white ]
6 I) R) k1 A: c! Q1 c setup-intersections3 K' M8 ]& I7 z* X' T4 _
end. S( |( [& h- e1 l" L+ |9 z
其中定义道路的句子,如下所示,是什么意思啊?+ k+ m' k! @' V3 q
set roads patches with: o8 x/ r% j& ~- Q- f; H; k9 i
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ {# a0 h' q5 \4 c: d
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 S& p$ U7 R3 ^& F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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