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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。
* u! B! G' ^: h% @8 o2 Mnetlogo自带的social science--traffic grid这一例子当中,
7 F+ d3 G: P) B' ~# a5 p7 z2 ?globals
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& q, e9 H' _- x! R& Q; U+ ^: l: m grid-x-inc ;; the amount of patches in between two roads in the x direction
+ ]" x/ T8 ]: n5 ` grid-y-inc ;; the amount of patches in between two roads in the y direction* Q6 b" C% ]" s# O; m C. J
acceleration ;; the constant that controls how much a car speeds up or slows down by if3 D5 K( f) l# d) w
;; it is to accelerate or decelerate X1 f3 {5 E+ E; Z+ R
phase ;; keeps track of the phase! [4 [, e/ J# l/ q6 J" Z# Y
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure8 K6 ]! Y, n# h& [
current-light ;; the currently selected light: \/ c8 s4 h: F. B
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;; patch agentsets
6 x% | P# r. y8 x' O intersections ;; agentset containing the patches that are intersections0 L9 B. w8 U; r5 H9 Q3 n. u
roads ;; agentset containing the patches that are roads) I2 F+ z* ?# M% y4 S% T% b
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: { Y K8 O& b. H& o6 k" Qturtles-own9 d% k# [/ j* m
[
* Q$ v$ ~( X7 L: f o speed ;; the speed of the turtle
. Y2 \, S8 o3 I) u' m$ l" U7 ~6 n1 X up-car? ;; true if the turtle moves downwards and false if it moves to the right
5 ~* l6 S" L p* Q2 D wait-time ;; the amount of time since the last time a turtle has moved/ I3 {3 f9 p2 r6 [5 X$ t
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patches-own
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$ d5 }; }7 I! p9 @ intersection? ;; true if the patch is at the intersection of two roads
( `/ r! E; Y1 |9 c/ ], S Y green-light-up? ;; true if the green light is above the intersection. otherwise, false.: S& q/ W0 S1 E) r3 |' u
;; false for a non-intersection patches.2 K' W$ ?3 W. G9 ^/ y/ g# l6 Q
my-row ;; the row of the intersection counting from the upper left corner of the J# M i; X5 E) R3 l% j% d
;; world. -1 for non-intersection patches.
& B( ?6 ? S! z& c0 ~ my-column ;; the column of the intersection counting from the upper left corner of the- m2 ^$ r& s: X8 m' t6 `' f- F
;; world. -1 for non-intersection patches.
$ ^; ]' @- j0 e e my-phase ;; the phase for the intersection. -1 for non-intersection patches.! l8 W; F/ A! B; v8 Y
auto? ;; whether or not this intersection will switch automatically.
: |, M% ^ V8 g3 v" l/ h6 w ;; false for non-intersection patches.
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/ S- _% b/ p/ O; g% F! F;;;;;;;;;;;;;;;;;;;;;;
2 h! F7 D( M! R4 s# E;; Setup Procedures ;;2 z M3 Z: f, t4 Q3 u
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
6 n9 ^) `6 n& h;; Create num-cars of turtles if there are enough road patches for one turtle to! s+ J5 j4 G- {* ~) j: H
;; be created per road patch. Set up the plots.
2 x' G. Q" r6 V/ Q ?8 v5 sto setup
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setup-globals
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8 d5 R& S" x6 b* S ;; First we ask the patches to draw themselves and set up a few variables
; ~- A/ q4 K' C2 D" P5 A' B5 j) X setup-patches
( S4 p6 P7 _, m) P9 ?& j, o make-current one-of intersections- u E+ Q" Q/ N
label-current8 ~; Y+ a$ z$ J5 f f
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set-default-shape turtles "car"
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if (num-cars > count roads)$ k& Y4 x% h# A
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user-message (word "There are too many cars for the amount of "6 Y: t, e% V0 Q- T( `+ |# x1 w( o
"road. Either increase the amount of roads ", d# e9 |' u) O! t; ~
"by increasing the GRID-SIZE-X or "4 X+ [% w/ J# E: n
"GRID-SIZE-Y sliders, or decrease the "6 ]6 X0 G4 I1 x" P
"number of cars by lowering the NUMBER slider.\n"8 @# |2 X& I1 q4 M" V) a
"The setup has stopped.")
8 e" c! s2 j) ~& z8 n6 ]8 |% x7 h stop
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: m# z1 O8 i+ v, c ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
* x2 ~& p4 I+ y* m, c# C0 H, M crt num-cars
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% Q4 C }/ S' k( V setup-cars
- {8 j1 X5 e0 b" j' V: | set-car-color% @# i9 a& ]. F6 ~: R8 x. \: ~
record-data8 B: J( k; }( M0 L: ~! e* O
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;; give the turtles an initial speed: y; i2 h8 S+ \. b2 ~# i% t3 o
ask turtles [ set-car-speed ]1 ^6 ]/ L/ _5 o& `/ ~
( I9 d! A( o: @- ?& \ reset-ticks1 ~& T' t& X+ W% A' _3 Z# O
end
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) n+ P6 ?# e* @;; Initialize the global variables to appropriate values
% {) R+ y8 Y. T, [1 G+ s) Tto setup-globals) M. [; |( Z- K8 ~* f* F5 V
set current-light nobody ;; just for now, since there are no lights yet; k8 i$ p# E: f1 A- m. R6 J w
set phase 0
% y3 x$ e$ W/ K1 S* A$ u set num-cars-stopped 03 ]; k( w5 n" |, p* m
set grid-x-inc world-width / grid-size-x
4 c, g7 I W, H5 e set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary8 i' w' J; S" c( H
set acceleration 0.099! U5 @: B/ D9 F
end( Q3 W) n1 W/ z- Y' z; I3 r
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
7 Q% [- K+ L Z: h;; and initialize the traffic lights to one setting, }( K/ W& c+ Z1 O
to setup-patches, h( @6 Y6 `$ n! b
;; initialize the patch-owned variables and color the patches to a base-color& s- K0 F3 m+ P2 y4 U: D
ask patches( A4 P2 {+ z% C$ Y' D( B N
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set intersection? false
$ Q6 S s* M5 C$ L set auto? false
! R. n* x- C& N; u! q: B# a set green-light-up? true. J: D4 }7 ~! B
set my-row -1
0 H* J* ]( }6 k set my-column -1* X; P6 w# A* i, S" S5 n
set my-phase -1: G& w2 z9 p2 F: P4 C+ }+ ?! g: t! F7 _
set pcolor brown + 3, _$ t" K* Q6 m& N: s' B9 V$ h/ g
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/ g' y# G) F I0 y, ? ;; initialize the global variables that hold patch agentsets
: [; _$ x r+ { set roads patches with! X: i' o$ X4 z) b( F A/ U' R7 Z5 [
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 S; ?5 g% U0 x6 L( `7 y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ t/ t! L# C# c5 E
set intersections roads with9 {% n- G" i0 p: V
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and$ A2 U" f* ~7 i7 T( I' ^
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 {) _' ]: e% K
+ a3 \/ e* v) G: S1 @9 |, V ask roads [ set pcolor white ]5 ~* I8 N# c2 q4 D! q; ]
setup-intersections# @ C. a/ u7 C3 c( j4 u
end
/ A( Q t2 \; U' Y; n其中定义道路的句子,如下所示,是什么意思啊?
6 u8 V1 r+ X* s7 X& D set roads patches with0 s9 n& O0 N& P6 M+ W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 z5 ]( R$ q4 I# n" U$ ] (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% `3 m5 ^' q" }( L- l0 o( l9 j$ a' Y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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