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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。9 X, z: U/ y: l) t) z2 X: r- g
netlogo自带的social science--traffic grid这一例子当中,
# q& {! ^) a: E2 G9 R r5 @& @globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction* p) t! ?, Z% r P
grid-y-inc ;; the amount of patches in between two roads in the y direction' r- T: K( \- R X5 y0 l; c1 G# ]
acceleration ;; the constant that controls how much a car speeds up or slows down by if, u* F% _% E$ }) z# z
;; it is to accelerate or decelerate3 A" u6 }; T, y$ g5 q+ n0 G6 C
phase ;; keeps track of the phase6 w6 U! |+ y6 R1 S- f% z1 o* c' o$ w
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure7 F, ~$ L- n# Y# l1 c5 }) ~
current-light ;; the currently selected light5 r+ r/ v: N9 N2 U
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;; patch agentsets
; [+ p: [, u' ]; d intersections ;; agentset containing the patches that are intersections( D) @4 D. S+ Z- X' S3 s
roads ;; agentset containing the patches that are roads
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, B; A& {' j, [! ~; j# Iturtles-own
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speed ;; the speed of the turtle
- y4 `+ u1 j. L5 Y up-car? ;; true if the turtle moves downwards and false if it moves to the right6 F: S7 W( F2 L L9 N5 I
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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, B( S6 [' C( \/ e) t intersection? ;; true if the patch is at the intersection of two roads
) t; ]5 M: ^ W7 U: P. J green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! G& {* P# n. U+ X ;; false for a non-intersection patches.7 b2 J# B0 z* F! T
my-row ;; the row of the intersection counting from the upper left corner of the6 }1 Y9 b5 D! F. k
;; world. -1 for non-intersection patches.5 H' E5 P" D9 z6 i; d
my-column ;; the column of the intersection counting from the upper left corner of the
3 g4 _7 W$ {8 ` ;; world. -1 for non-intersection patches.
: Z) K- i# L- S+ P. a my-phase ;; the phase for the intersection. -1 for non-intersection patches.6 U% U- ?$ [, C2 u: }- |) g
auto? ;; whether or not this intersection will switch automatically.
4 i/ M( T3 [' d1 q: w# p ;; false for non-intersection patches.4 h6 ?" S2 |* e& J: q
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0 x( c% L6 I" l& b( P! z0 T. Z;;;;;;;;;;;;;;;;;;;;;;$ ?' I' r- I: k& p
;; Setup Procedures ;;' r+ S0 a- \* S1 Y! f9 Y" f' @1 l4 h
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.- u! `' k/ O2 A9 ^
;; Create num-cars of turtles if there are enough road patches for one turtle to
, b' T' ^. ]/ j* A5 n: p, c: V3 h+ e;; be created per road patch. Set up the plots.0 C+ ^3 s# A+ k6 e$ @* ]
to setup
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setup-globals
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* \* Y% z% A( A) N1 y; x* ?" u$ r, m/ K ;; First we ask the patches to draw themselves and set up a few variables0 A. P. ?3 q" a) A% ~+ a8 }" u
setup-patches
0 ~' S/ d5 d" t6 o1 I- t make-current one-of intersections
& N0 l/ x3 H) ~# a0 g1 K label-current- H- |+ B* z6 q' @0 _5 I6 n
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set-default-shape turtles "car"! a! j o6 P# E9 V: i) C
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if (num-cars > count roads)' a P4 x4 H9 m; T
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user-message (word "There are too many cars for the amount of "" m- `" Z( r& ~
"road. Either increase the amount of roads "
4 B* S$ J9 \, e' n4 ?6 Z "by increasing the GRID-SIZE-X or "
- p# T( _' p9 Y$ D "GRID-SIZE-Y sliders, or decrease the "
7 P9 \8 W9 _6 h" K "number of cars by lowering the NUMBER slider.\n"
5 g& \$ x: U8 z* s- H3 o3 | "The setup has stopped.")! B! R n5 n) E8 Y+ z
stop
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5 h4 h) p+ p2 A1 |3 C4 I* a ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
% `! a: A, Q8 l8 Q- _. d crt num-cars! u. `9 e4 @" M; g1 I6 a4 c% {3 ]
[
2 t7 W' o! Z6 p! n W9 \ setup-cars6 |7 x% ^8 [/ C8 q9 s
set-car-color
- K7 ]( o! q, U3 V3 n) J record-data
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6 |/ ^) s& t5 G8 l; C9 W: ^# x4 u ;; give the turtles an initial speed
* b* o! f+ |- z1 W9 z' C ask turtles [ set-car-speed ]
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# ]. f! R f" T9 @2 u reset-ticks% ?; Q& ^0 |* B+ i8 u5 B
end
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;; Initialize the global variables to appropriate values" h" P0 y/ ~5 {/ R
to setup-globals
; W- O( K9 ]" v set current-light nobody ;; just for now, since there are no lights yet
4 U1 r! x" A( `& }( w set phase 0" E7 c0 ^6 G/ ]% J0 U
set num-cars-stopped 0 a2 i @" c4 y. O
set grid-x-inc world-width / grid-size-x1 Z: k, H9 Y: N
set grid-y-inc world-height / grid-size-y
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4 ]1 C: y/ G/ T ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary. ]" R* A# ~% G6 K. ]
set acceleration 0.099& U) c/ }2 v( S: G
end$ p3 {3 \8 U6 X' W. ~
3 ]: R% G! b$ n/ v6 q- ^& T' r;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
) |; U/ x$ i8 |: I5 F, y2 p r;; and initialize the traffic lights to one setting8 z* l; @ V9 t4 X) Y& i* d; B$ q1 Y
to setup-patches$ e* v r1 u3 b5 J' j% n
;; initialize the patch-owned variables and color the patches to a base-color. K; x1 |! g3 _& o# f- U
ask patches$ ^" S; \( M8 Y- c" ~
[
9 O* C: g: Q' i X+ X set intersection? false1 W$ o5 G: s1 V, R3 Q
set auto? false* I$ ~; f' e1 F+ H! I
set green-light-up? true
5 m# l5 d, ]8 J- v, f set my-row -1/ X" L# C8 D5 \, }
set my-column -1
! n* u1 e4 a# ^( K O& h set my-phase -1' ^6 Y. o/ ]( A' q U
set pcolor brown + 36 B( @7 ]% D' A9 x% G8 b. {
]
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;; initialize the global variables that hold patch agentsets( L' g: h3 }0 M+ E( X
set roads patches with
+ b1 |8 e( o9 C# c [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ _/ t) h* w0 P- S
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]' [9 Y. o9 h/ K
set intersections roads with
% a% Y5 p$ T" g [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and7 m! J& ]4 ` {' O1 J S9 U
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 c, [% R% E9 K8 a1 J, S, b9 z/ L; h
: ?) \: U" b7 x* F6 ?0 h ask roads [ set pcolor white ]
/ l: P1 D, }' @& t+ n% M setup-intersections# i# m, v ~5 Z: [6 [
end* Q9 v$ D3 Y8 ]4 V
其中定义道路的句子,如下所示,是什么意思啊?
+ z! `6 E' Z' p set roads patches with6 M: q; o0 P: |: A
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
W4 ^# `. j$ u. E" n: ^ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 Z0 ]7 L% n6 f& X; d- i. Y+ K/ c
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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