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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。
) N( G* E$ ?: J) N8 N. i& cnetlogo自带的social science--traffic grid这一例子当中,. ^0 v# T8 K C% Z
globals' ^' N Z. w) l v- K: v( K, \* l
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+ y) U3 |0 [$ b grid-x-inc ;; the amount of patches in between two roads in the x direction
; J s. R& U2 E9 ^ grid-y-inc ;; the amount of patches in between two roads in the y direction
" K" A5 M( @7 I9 c, q# q1 O acceleration ;; the constant that controls how much a car speeds up or slows down by if
3 w9 B* h5 d: A# [9 Z9 X- h ;; it is to accelerate or decelerate, S( f1 P. g9 p& U0 u, l4 h
phase ;; keeps track of the phase
8 }: _0 T- k6 V/ ~5 L8 X6 L% G num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
% R! v2 t/ Y. i8 A current-light ;; the currently selected light! v/ w" d' L, Q
1 p$ a! M, Q6 O! ~3 n ;; patch agentsets
r0 ]1 y* W j' c intersections ;; agentset containing the patches that are intersections
8 z1 K+ S# I( M m5 R- s roads ;; agentset containing the patches that are roads
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" X! o* ~; q9 I1 rturtles-own
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speed ;; the speed of the turtle/ x& f% \2 H- I6 M; z2 s! X
up-car? ;; true if the turtle moves downwards and false if it moves to the right7 w6 G4 c: k; {2 g, \+ i
wait-time ;; the amount of time since the last time a turtle has moved. N( l# p' h8 z; A
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7 H9 {* H8 g4 @3 a* C( |patches-own
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5 q. f4 G7 w2 d9 K% M& l5 U intersection? ;; true if the patch is at the intersection of two roads
8 r9 B/ ]0 g$ h Q2 [ green-light-up? ;; true if the green light is above the intersection. otherwise, false.
: E1 D o! T8 [8 o( W8 K$ c; [1 _% V ;; false for a non-intersection patches.7 W% s \. B# @ @+ u
my-row ;; the row of the intersection counting from the upper left corner of the
5 T/ a$ C6 w7 y4 g# N ;; world. -1 for non-intersection patches.
) L# ]( X3 I. L0 x/ f my-column ;; the column of the intersection counting from the upper left corner of the
' W, e0 j7 i0 r4 G; M ;; world. -1 for non-intersection patches.+ d9 I7 v$ o' H T$ [& ` I) [
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
$ m9 B' y u2 o& f$ X$ n1 _: _8 | auto? ;; whether or not this intersection will switch automatically.: F3 A; W% |8 a& m1 V$ |" R8 b
;; false for non-intersection patches.5 e3 Z N/ G- H8 r$ W: t) t0 h
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;;;;;;;;;;;;;;;;;;;;;;7 w* S9 d, ^' n8 Y$ h
;; Setup Procedures ;; W' R# j9 d/ C+ f6 b- A9 F8 C
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.# C" \9 H g% v d; ~
;; Create num-cars of turtles if there are enough road patches for one turtle to
% ^, {3 s% d3 q9 s;; be created per road patch. Set up the plots.
. [ A$ c3 q* K- Eto setup
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& E! b9 c _0 V$ i, {# n setup-globals
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;; First we ask the patches to draw themselves and set up a few variables2 ?) M$ A7 U, I+ m* [% T' M6 W
setup-patches
2 M+ ?3 Y# h. H, B3 u `. O make-current one-of intersections
0 x' H% c: [- n. G3 ]) m$ E label-current3 i. C3 H% |. Z4 z9 z g- a
; q" e2 N6 h, F) g6 s* ]' G1 q set-default-shape turtles "car"% x, r. T, Q& g/ V0 q1 d
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if (num-cars > count roads)
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/ t$ p6 z6 t4 O& I% e user-message (word "There are too many cars for the amount of ": ~, p- N( w2 b' N! k$ q; N7 k+ N
"road. Either increase the amount of roads "
; W F) M4 ]! n% q ?; W' B "by increasing the GRID-SIZE-X or "
1 x( l. m( j& V' `+ G, Y6 q& y" L "GRID-SIZE-Y sliders, or decrease the "
' l, S. }( u! |5 e7 H "number of cars by lowering the NUMBER slider.\n"8 {6 G2 d! S% J6 r" p [0 Q7 k
"The setup has stopped."); n8 l6 @8 t ?5 p" ~, o6 ]
stop3 N) K6 X! z, T K+ T
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
+ Y0 e" n" [: ] crt num-cars! y# i; C0 O3 ]/ }( y2 @9 c
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/ I% N( z- q9 J: T* _5 B$ |' }; Z! _% ^ setup-cars
8 j; e* p) Q) o% z; W2 q& b set-car-color
6 N8 B5 [" k7 Y2 [+ a record-data
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;; give the turtles an initial speed
( C0 G1 y8 H9 l3 }' Y& F ask turtles [ set-car-speed ]8 T# k* L2 ^. d0 o8 j
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reset-ticks; i! m' [, Y8 s' k
end6 D' Y+ _/ O+ S" d, E4 r
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;; Initialize the global variables to appropriate values1 e! ]( {/ H) s0 X) W3 W0 P
to setup-globals/ \: f, R* C" r! Y" a
set current-light nobody ;; just for now, since there are no lights yet
. A$ X }' ]0 d& t2 ^# g, f set phase 0
0 q l$ I. [6 V9 E& m7 e6 B O { a4 | set num-cars-stopped 0
% \# U3 D5 Y7 O% D0 l3 z: | set grid-x-inc world-width / grid-size-x
/ x9 I( l& w, t! b- V4 x T set grid-y-inc world-height / grid-size-y
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. N0 h- F5 b0 c ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
6 @0 d. ~. ]( Z# j, ] set acceleration 0.099, y. M8 _ z7 l7 r: v! W( v
end# H! g/ B& ~/ V' _% U
$ w: f* W& N, I9 ];; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 }3 W2 {1 _5 Y' c& h$ a) M;; and initialize the traffic lights to one setting! m& s6 {; D8 t$ B5 E# w' ~
to setup-patches
- S7 Z$ n( B( c+ E ;; initialize the patch-owned variables and color the patches to a base-color
4 f4 {6 f( N4 j, q ask patches# d# [4 g4 t$ \# x( o
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set intersection? false
* x' @7 U7 m2 G2 g; }& f* i& v* c set auto? false
/ {3 i) V6 ]$ b9 I% Z3 o4 |6 T set green-light-up? true
! r$ U' Y- G v4 a set my-row -1
+ ]' i! V* Z& A0 e set my-column -1
, k/ S8 [5 b" g set my-phase -1
' o6 W% k7 c$ K8 G set pcolor brown + 3+ J( m! `/ N1 l
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! Y6 J( ?$ m4 \0 L ;; initialize the global variables that hold patch agentsets
# f/ G" d3 m$ ^! X7 { set roads patches with
5 {+ B9 x, P% u- v6 m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# |% a) y4 P9 _5 F+ f (floor((pycor + max-pycor) mod grid-y-inc) = 0)]# c/ S, L, ^# L# E: m0 p, D6 F3 v
set intersections roads with% n2 \; R8 W: H
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and1 `+ g( y! d" {! V
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]" q4 o/ V' A% C* U6 E
setup-intersections4 \0 W% c- c; A& E; [9 W
end- e6 ]1 r. D6 i$ D y1 n
其中定义道路的句子,如下所示,是什么意思啊?
5 E: D6 ^8 `/ { y( J set roads patches with
: a$ m4 o) G2 b5 h4 H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 [- _- I$ u3 m y) `
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 e6 G/ R/ m) }" E) J/ x% d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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