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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。
2 G# J/ G% \& k4 Rnetlogo自带的social science--traffic grid这一例子当中,
& N) D u" _1 g u7 L( Mglobals: u6 m- D0 R' V4 c. Y# s b
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grid-x-inc ;; the amount of patches in between two roads in the x direction4 Y' Y5 o" l0 }. y7 R
grid-y-inc ;; the amount of patches in between two roads in the y direction
3 @$ B$ ?4 Y Z* R2 N acceleration ;; the constant that controls how much a car speeds up or slows down by if
& I B/ ?3 t% h! h( e% S ;; it is to accelerate or decelerate
9 R& u) n, ?8 K$ s) {; W phase ;; keeps track of the phase
2 ^% \5 b$ [! v! E num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
3 L+ j% \- g9 ~ current-light ;; the currently selected light+ w- g7 y' @: }
! [/ {* o+ A( l9 J$ l9 z ;; patch agentsets! [' M) E$ {4 j
intersections ;; agentset containing the patches that are intersections
D2 C# e- f/ H9 I roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle; r& D1 m6 Q5 z0 V0 Z, U3 g
up-car? ;; true if the turtle moves downwards and false if it moves to the right$ {6 ^ ^6 c9 K4 B1 Q6 G
wait-time ;; the amount of time since the last time a turtle has moved; J5 _0 ]" E* `& S% ]6 c: Q7 r
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patches-own2 F t" k/ w' j5 o% _
[
6 X; }; A- s( f y! ? {$ r intersection? ;; true if the patch is at the intersection of two roads
8 E0 n( _$ T" Q. H green-light-up? ;; true if the green light is above the intersection. otherwise, false.
0 B$ d* U5 L u3 D ;; false for a non-intersection patches.
( i2 C% |" z# ~: F0 c8 m& P+ M+ k my-row ;; the row of the intersection counting from the upper left corner of the
# {# @! `" D* W ;; world. -1 for non-intersection patches.
/ p8 p& ?! S* |: y9 h& s+ b my-column ;; the column of the intersection counting from the upper left corner of the$ \' p) |4 G8 p$ ?* } d
;; world. -1 for non-intersection patches.
7 R8 G3 ~6 Q5 ^( J+ @ my-phase ;; the phase for the intersection. -1 for non-intersection patches.. \8 u4 G7 a3 q7 A9 B; A
auto? ;; whether or not this intersection will switch automatically.* E; b- V+ Z7 \! { ], H& x
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;9 S5 ^1 O, ]5 g) g
;; Setup Procedures ;;
( F+ q0 D. O% ?;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.; q, O G$ S# d& U% }$ a5 V
;; Create num-cars of turtles if there are enough road patches for one turtle to
9 V- H2 g2 h R) ^* X# F6 ?;; be created per road patch. Set up the plots.
. ]# N7 T- T* e. N# Yto setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables0 y1 C! O G% p; m$ I$ L1 |/ w. J% G
setup-patches" ^4 Z- o: x) k- B2 x. ]
make-current one-of intersections
) J/ o# v8 ^3 f1 b+ K! q label-current
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set-default-shape turtles "car"
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" p' C( C/ @5 ~ if (num-cars > count roads)/ i/ k* m6 S' b2 l7 \+ g; u% P
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) j# @+ w! a3 Y user-message (word "There are too many cars for the amount of "
; |, { p5 A9 N3 m Y' y! W "road. Either increase the amount of roads ". b4 |: N' d) e+ C/ V
"by increasing the GRID-SIZE-X or "
# P& E3 c# @9 f' y# a "GRID-SIZE-Y sliders, or decrease the "
! r( c7 K. @3 l% i9 D+ v "number of cars by lowering the NUMBER slider.\n"; N( l" X' Y% e$ C2 U% i
"The setup has stopped.")
& n. K( |# n+ g# e; }" x stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
3 D' B7 d. h6 J! D crt num-cars" h* e1 B9 y5 R7 u2 F
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+ p/ c. I* N$ @2 {4 ]9 m+ L9 G setup-cars
. C5 `( C2 |+ }' G) q \! S# h set-car-color
; s5 q6 v/ ` Z2 C7 t! r& N record-data% f4 e4 `( ?$ m7 b- O0 w' W
]
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;; give the turtles an initial speed
& S$ S' x" r# e) H1 s4 J ask turtles [ set-car-speed ]' M) \5 K, ?- Z" d
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reset-ticks1 C4 o" F4 s: O) ~" ]* R$ Z& L
end; u: P$ T: f( u) R6 W. x
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;; Initialize the global variables to appropriate values
, X/ j5 j9 {2 u7 p Mto setup-globals
( `8 Y* |. x9 t& K: O set current-light nobody ;; just for now, since there are no lights yet
6 Z1 W5 w$ o3 K; C set phase 09 {- J' Y* o Z$ K: C
set num-cars-stopped 0
1 e+ X0 N1 X% S5 a# w set grid-x-inc world-width / grid-size-x
( }; Y$ f) }+ O, U* E$ Y set grid-y-inc world-height / grid-size-y
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, F- i m/ T7 t* _8 h) B. x ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary: w% K) @6 R$ J& q
set acceleration 0.099
5 r I" f: h: S! I1 ^end
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8 w- V% d8 o1 M4 N, ];; Make the patches have appropriate colors, set up the roads and intersections agentsets,/ D/ Z0 O. B k4 ~3 E$ e. J8 f: t
;; and initialize the traffic lights to one setting
6 O& v( v( E5 g6 y. x! M- E; jto setup-patches
/ U2 ~9 B8 K, ` ;; initialize the patch-owned variables and color the patches to a base-color
, ]8 ]0 N1 B* L. @0 ]0 |- R ask patches1 o. I1 v9 E* @7 u# {& k! }
[
" D7 t) ^, P+ @ set intersection? false
, H6 _3 {- x1 r- ^# p set auto? false6 k" n/ J6 z( u$ J7 X
set green-light-up? true' e. o; u! T9 W
set my-row -1/ K. x. L4 k4 K( E& M; r
set my-column -1- n+ D: b5 ` |% P- m: o
set my-phase -13 ^8 W, W/ C8 |" @. B# k. c# v
set pcolor brown + 3
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6 |! E: Z( J; [ ;; initialize the global variables that hold patch agentsets
* D2 ?0 c/ S! z* S5 f set roads patches with [! F6 g% ^5 g. i2 L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
9 m) B0 K, ?0 W7 U' y0 x! B (floor((pycor + max-pycor) mod grid-y-inc) = 0)]* C8 z% Q: e$ j$ X% k
set intersections roads with
. [2 t1 z6 }* T% n# w [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and/ F4 i' u# A$ Q3 j$ h- Q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]2 \' E% X' z$ p3 f) g
setup-intersections/ B+ M) _ [% X( A0 |: s/ f* e9 y/ K
end
4 @: n0 U; `" W其中定义道路的句子,如下所示,是什么意思啊?
3 K% Z& ~) \, q$ n0 R: S8 e set roads patches with
! `; r' _3 R4 v! Y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or9 f) A, f( Q6 n
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
! s0 E1 I1 E5 E' |7 Y9 {" \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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