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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。. M* ]+ e/ o; v2 B) i' b" [1 P
netlogo自带的social science--traffic grid这一例子当中,
4 a8 P+ X+ k9 a- ^% {globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
/ E/ \5 b$ E/ O1 E- F" [* M1 g2 ~! D7 g grid-y-inc ;; the amount of patches in between two roads in the y direction
/ G2 {" w4 h! _& h) ~$ r/ d0 ?' S! [9 g acceleration ;; the constant that controls how much a car speeds up or slows down by if
: M' Y: |6 o1 i, r" x ;; it is to accelerate or decelerate
' \" R0 b! ~/ g1 ^! ~3 A phase ;; keeps track of the phase
7 y% Y* S# u k- f! n. B7 }4 _ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure; ~# M/ `. b5 l1 ?" P& I
current-light ;; the currently selected light& |5 L6 }% t5 U+ f% M- [
. a6 |5 n, Z* E ;; patch agentsets
. u9 m5 N1 y9 v3 ]$ ^ intersections ;; agentset containing the patches that are intersections
! g1 o9 Z, P1 N roads ;; agentset containing the patches that are roads
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3 r% F! `) t% i# r9 s" n9 p8 g, _turtles-own1 e# H( q, ]3 X f( `
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speed ;; the speed of the turtle- {" |- Z0 c- l+ g5 ^+ ?' E
up-car? ;; true if the turtle moves downwards and false if it moves to the right4 ?" Y% i8 x- ~! y; L
wait-time ;; the amount of time since the last time a turtle has moved, Q9 C0 [$ F' X; y. h, G
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads% Z* K% z0 X, Q8 L5 E) S, ?
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
( u" z8 ]$ W8 Z ;; false for a non-intersection patches.
& G, x) R$ F3 u/ R" L6 w8 W5 [ my-row ;; the row of the intersection counting from the upper left corner of the7 `# X! w( ~8 P) A' w D L
;; world. -1 for non-intersection patches.
9 m. D* C6 X$ V my-column ;; the column of the intersection counting from the upper left corner of the! }& Z* Q$ g3 b: X0 l
;; world. -1 for non-intersection patches.
: W0 I9 v5 o2 D: r% O my-phase ;; the phase for the intersection. -1 for non-intersection patches.
. x3 R/ {2 _& } auto? ;; whether or not this intersection will switch automatically.
) |! a( Z- T% f/ { ;; false for non-intersection patches.4 S- d2 R7 K4 @( b: p6 R" _
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;;;;;;;;;;;;;;;;;;;;;;
8 n) U7 M& ^1 p9 i4 h/ ?;; Setup Procedures ;;
$ ~/ R4 s( ?+ W) \3 ^;;;;;;;;;;;;;;;;;;;;;;
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. Z+ N! @/ w% G8 ?;; Initialize the display by giving the global and patch variables initial values.# Y z$ ?! h6 R' T/ U
;; Create num-cars of turtles if there are enough road patches for one turtle to
+ F4 ?* ]; {5 p: n6 P: \( N;; be created per road patch. Set up the plots.
4 T/ ~3 F- ` c) ~! }% q j( mto setup c8 ?$ H0 g9 y) N! F
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setup-globals4 s: F2 t( h9 f( [; x: m5 C
/ T) w& T0 {# o* V ;; First we ask the patches to draw themselves and set up a few variables
, y# a7 ?0 N) O2 C setup-patches1 M( X! i) y$ O# z! F$ E% s
make-current one-of intersections
- W' V% B& C( y" s% ]' o% A: L label-current
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3 Q( r+ n5 E( F$ Q2 o* s) k set-default-shape turtles "car"5 `* w) [3 O A( c) C) ^
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if (num-cars > count roads): O6 D/ M( t# {& G5 U' W
[
) Y8 q3 \: q! C; x' Y user-message (word "There are too many cars for the amount of "
9 V" i+ y8 {0 j "road. Either increase the amount of roads "6 S5 L" q; b' S/ W% L. I! o
"by increasing the GRID-SIZE-X or "
4 r$ e( E$ U( Z; e "GRID-SIZE-Y sliders, or decrease the "
9 x m, |9 m2 t "number of cars by lowering the NUMBER slider.\n". `0 v0 f/ }6 x8 C" I
"The setup has stopped.")9 w5 h; i4 d5 a# n O- g
stop4 R, E" B' k0 v0 q% E
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) z% |! ?$ _4 m7 e: i2 T" X. s) W ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color/ H( T% |/ ~+ Y' W& ^
crt num-cars
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setup-cars- M) w5 b- e+ Z i4 {
set-car-color
; b/ Z' Y0 [& Y0 B5 k) u, e; Z9 T record-data
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;; give the turtles an initial speed
3 w' A% U. g S* Y7 M0 L1 i ask turtles [ set-car-speed ]
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reset-ticks
7 H! B7 t; G+ F3 F- u* _. X# Dend) H; Y3 Z8 T& D' A/ m% x" b
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;; Initialize the global variables to appropriate values
9 t1 |0 H, l$ P R3 w7 gto setup-globals3 B3 V5 O' ~/ f# S7 Z2 | _' A
set current-light nobody ;; just for now, since there are no lights yet" a: }0 h2 ?0 S& U
set phase 07 i4 `- m, t3 `# [+ q
set num-cars-stopped 0
! S7 `' G' t: z2 e+ x" o6 D set grid-x-inc world-width / grid-size-x
- L8 w* z2 {+ ?# z( B set grid-y-inc world-height / grid-size-y' n* D' m' _( U. j! l
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
! p1 @! Q d: D set acceleration 0.099
( x$ t) u- a2 N9 S7 X# Dend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ ?7 w8 y" o% p+ m
;; and initialize the traffic lights to one setting- Y* j3 U; N5 V% |3 y
to setup-patches0 R: e9 E* V. d) m O, h, g! D3 U7 R3 z: l
;; initialize the patch-owned variables and color the patches to a base-color
* ^1 ^, Q1 ~% e3 a1 w! d, \0 H ask patches
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9 |+ E! W8 g/ N& F set intersection? false
0 l2 O& y3 j Z! O$ ] set auto? false a/ j$ P1 @% g2 l9 @
set green-light-up? true: c7 S) H7 v }$ Q
set my-row -1
7 ^1 j v$ [$ x' W" w set my-column -1! @& E1 R9 ~7 G0 J# U# d8 E {
set my-phase -10 ?" ^* s+ f/ H) b
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
" O' n' j/ `2 H5 m- K; v set roads patches with
9 J* J0 e$ `0 P8 W [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! w3 R- O$ M! z" H+ }" c! I+ g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 i" A3 u8 n' E( I m set intersections roads with
3 E6 p, Z' M5 ]/ e' z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
) b, T1 F" w- K5 o; G A (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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9 C1 Z `# S# T5 ]/ j5 U( P/ T7 C ask roads [ set pcolor white ]
1 a' P9 c. W& W1 N( H setup-intersections/ H: F4 z* C8 d# k" w
end
, {7 K/ p: j3 l$ y/ A其中定义道路的句子,如下所示,是什么意思啊?/ `3 _9 Z9 t; J/ G7 ]! x
set roads patches with+ \( z* S5 Q2 u3 V5 Z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! J, `; b8 ~2 ]( k9 J (floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 Y$ Z5 i3 L" M# F# [
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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