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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。
# `, D4 P1 [& B) v# M- q- c! }netlogo自带的social science--traffic grid这一例子当中,
1 J, D# D% t5 r3 R2 Nglobals {2 [3 f T! [( {
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V3 r# R1 K, P+ G* a5 S grid-x-inc ;; the amount of patches in between two roads in the x direction
8 O1 D$ I* s9 |* I/ j9 p grid-y-inc ;; the amount of patches in between two roads in the y direction
& c$ X- V9 H7 s* n, T5 \ acceleration ;; the constant that controls how much a car speeds up or slows down by if
{6 z8 v- j- h9 `4 m# c* A ;; it is to accelerate or decelerate
7 b; [: R" @8 S) o$ U phase ;; keeps track of the phase
& r# f/ ]7 p4 m8 U6 B num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
* ~& V9 U* Q9 Z4 U: }$ J current-light ;; the currently selected light
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;; patch agentsets
4 S) X( ^0 y2 Y0 B: F; ^ intersections ;; agentset containing the patches that are intersections3 U) ~+ \/ C* j! ^2 M
roads ;; agentset containing the patches that are roads# w! B! Z, r0 Y7 y+ c2 R
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* ~3 G8 k0 H, Z+ t8 g1 ]! pturtles-own" j% m( L4 ^# B4 U' i
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. U; H; y" a3 l) J; T6 m8 O) _ speed ;; the speed of the turtle
3 `1 p/ Q1 R" E# ]+ y9 L up-car? ;; true if the turtle moves downwards and false if it moves to the right
' }* W B6 ?+ O wait-time ;; the amount of time since the last time a turtle has moved. g8 K7 }2 r2 Z7 E8 }
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patches-own
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2 Q7 x4 v3 b: o8 T, o v7 m intersection? ;; true if the patch is at the intersection of two roads
4 e) [) ?/ @5 b+ ` green-light-up? ;; true if the green light is above the intersection. otherwise, false.* a9 D) T1 w9 D9 T
;; false for a non-intersection patches.9 d5 A" r9 M% v& z( u! T3 `* G
my-row ;; the row of the intersection counting from the upper left corner of the* ], ?1 k/ X, H C9 \
;; world. -1 for non-intersection patches.
/ F' k- W+ @2 G9 O9 }5 a5 M& u my-column ;; the column of the intersection counting from the upper left corner of the
6 O2 k1 @0 ?2 Z6 _6 Y ;; world. -1 for non-intersection patches.. Y* i' K$ j7 v# j7 [0 x- f
my-phase ;; the phase for the intersection. -1 for non-intersection patches.4 n3 l3 a! V1 F
auto? ;; whether or not this intersection will switch automatically.& O- M0 M" @- {
;; false for non-intersection patches.! ?4 _ b1 d! r: |; u$ v
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9 u; N" C! M. U; m9 }( H. _) Z9 R. \;;;;;;;;;;;;;;;;;;;;;;
[# x, n& `1 j( x5 E) u, h% w8 o- o;; Setup Procedures ;;5 |- c$ i' l! l7 i1 n9 t3 f
;;;;;;;;;;;;;;;;;;;;;;8 N& L7 q3 o5 r7 U* [3 F
- [4 G8 b0 V4 Q1 A4 U4 e;; Initialize the display by giving the global and patch variables initial values.
: r5 g4 W8 c: [( H2 H;; Create num-cars of turtles if there are enough road patches for one turtle to4 a. _ G+ k% Y9 {
;; be created per road patch. Set up the plots.
' ]$ U9 c7 o3 h7 ?to setup
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( O# M+ b3 O) X0 k2 S! k setup-globals
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0 Q9 a9 [/ i8 Q ;; First we ask the patches to draw themselves and set up a few variables
1 f5 G! C( L1 F# M' k setup-patches
# N. C6 b) [2 [6 \ make-current one-of intersections0 a! d" P U! @; e! P9 N
label-current" n& O- ^! Q; b. v0 a9 S S
- H5 [/ \6 C+ M7 y7 k set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
' L& [6 c- C9 ? "road. Either increase the amount of roads "
2 Y% O9 Z3 U: u# A$ W "by increasing the GRID-SIZE-X or "- \+ ]9 ?! |" J+ O" G/ _
"GRID-SIZE-Y sliders, or decrease the "
( I! {* a; V( k! r d "number of cars by lowering the NUMBER slider.\n": L7 R; d2 b" V$ ?2 }9 n$ L2 `
"The setup has stopped.")( _1 |6 m6 n# F. @4 G+ ~9 ]
stop4 }$ B- E4 c& Q/ n& {/ n& W6 Z
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color% Y* J: t/ Y5 Q! F1 n, H* k; X( }
crt num-cars4 K) W2 d) F6 w
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- `4 M0 r. o' g, a2 W setup-cars
2 ^& t8 j7 `: E) L! | set-car-color; h9 k" K! k/ b; i# |: r0 {7 w
record-data$ I7 Q' \9 K$ w' K* [" m/ `
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;; give the turtles an initial speed
) p1 ? J3 S- \; ^, P ask turtles [ set-car-speed ]
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reset-ticks6 `6 x7 q% R3 w5 d, I* ?
end
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;; Initialize the global variables to appropriate values6 ^# a3 r$ t5 B
to setup-globals
% [1 G4 }( z8 W' @7 V set current-light nobody ;; just for now, since there are no lights yet& I% `( \( }% Y' G
set phase 0
: V& c9 b, z, p set num-cars-stopped 07 E. h: v# E, _# k
set grid-x-inc world-width / grid-size-x. B* Z, {# K: ] N4 w/ T
set grid-y-inc world-height / grid-size-y& T; H4 L" F/ t c1 h7 ]
" Y5 V6 _) f# U5 L2 D' N ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary8 p/ C/ v/ L/ J) u% F% e
set acceleration 0.099" R/ I' n5 u' n" L
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,. Z% j: K1 t. L4 l, l1 r E/ `
;; and initialize the traffic lights to one setting
5 K# t- L3 C& k& @, F1 d9 tto setup-patches
* {! Q) `+ w& S$ X ?$ ~ ;; initialize the patch-owned variables and color the patches to a base-color- S6 w u- m6 q# u" T
ask patches/ b& M( r! v. c6 T6 D$ ^
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set intersection? false
7 f. a( V5 `0 q) j set auto? false+ ]' l. H3 P9 b+ c5 |# f$ J
set green-light-up? true
7 u* l4 w1 z! Y1 \4 r, o' x set my-row -1$ G* [2 l+ \6 n1 A
set my-column -1
, ]( X1 L. O2 N! N" b% H2 H6 s9 Y n set my-phase -1
5 `: {& B5 V# y! w1 S' i8 Y* H0 c set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
$ h$ H6 n! [9 ^8 U4 \% D set roads patches with9 `8 k9 [3 A& d8 }: t7 g4 A- _
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! y5 {' }' w# m2 @; j (floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 \4 [. T6 O: q! E, h6 x9 }
set intersections roads with# m1 V9 o `/ n9 o% \
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
* H( ^' I6 c2 x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]: Y$ P2 k; e# y* R M3 X
setup-intersections$ Q8 ?2 |6 M) S2 k% J Y* x) N
end
9 y# w3 l8 k8 R" |; l" q2 h) ]其中定义道路的句子,如下所示,是什么意思啊?
n0 \' t C/ W7 u+ w% B' S. h set roads patches with
4 e; l0 N" H& N4 N [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 r* J' E+ h* X
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ P9 t' c) x& O1 J1 N) c! E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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