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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。
5 @9 R* V8 N) ]' {4 a5 j: N5 T- vnetlogo自带的social science--traffic grid这一例子当中,: i2 W" h+ R, \* l
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction4 m3 R4 o0 A2 R2 K. w; P& I( {
grid-y-inc ;; the amount of patches in between two roads in the y direction$ A, O% d2 }/ {1 Z( \" N+ t
acceleration ;; the constant that controls how much a car speeds up or slows down by if
( Z3 [5 O7 ^( [) x) w ;; it is to accelerate or decelerate
. e) f- b9 ]6 q phase ;; keeps track of the phase
$ g+ q4 ^/ e" r/ t) {0 q num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
. M% }. U( ~/ I& o2 P! d current-light ;; the currently selected light
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2 k9 J3 {9 F0 m ;; patch agentsets
0 s, K; B2 n% ` intersections ;; agentset containing the patches that are intersections
! }3 w/ v+ s3 p5 @! m6 U roads ;; agentset containing the patches that are roads4 }+ s+ v7 h, A6 s, W
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. F- s( m: P0 t; @' {turtles-own6 {( F8 D' B( x9 X G- E& p0 Q
[
8 _. V3 J& B8 Z5 _+ ` speed ;; the speed of the turtle
6 P9 o% Z0 |5 g5 ~* i' m/ J; b up-car? ;; true if the turtle moves downwards and false if it moves to the right
3 O/ Q1 c6 U a6 y: @8 f5 D wait-time ;; the amount of time since the last time a turtle has moved
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9 ~ ^/ \' @2 W N; Lpatches-own) n3 U1 Q+ R2 m, o3 S2 |3 c
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intersection? ;; true if the patch is at the intersection of two roads! Z7 a9 J9 V0 p! [" {
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
2 _$ M" `% ?- ?- a) o ;; false for a non-intersection patches.
1 q) `! s4 p0 j" G2 k. ? my-row ;; the row of the intersection counting from the upper left corner of the
4 L+ ]' S4 ?% p4 F2 K2 L ;; world. -1 for non-intersection patches.# e; E# m3 T+ n0 [1 F' P
my-column ;; the column of the intersection counting from the upper left corner of the& D# y3 g3 Z7 U% d. u0 r) `. }
;; world. -1 for non-intersection patches.6 u9 ]9 E/ u2 k, o3 W4 l
my-phase ;; the phase for the intersection. -1 for non-intersection patches.# n7 M9 h4 z! k( R/ B3 u+ M
auto? ;; whether or not this intersection will switch automatically.
3 }8 I2 @: l0 f5 r1 b* x ;; false for non-intersection patches.: z( I( z, I: d6 z; r$ G% S
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/ @5 G% H9 G. }. H! };;;;;;;;;;;;;;;;;;;;;;
: O& |# o: H& a;; Setup Procedures ;;
3 o: g& w+ I- O8 S: h6 l;;;;;;;;;;;;;;;;;;;;;;
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+ i8 s. X0 Y1 D. s/ U6 L- F8 ?;; Initialize the display by giving the global and patch variables initial values.
/ W9 o+ B3 f- B% p;; Create num-cars of turtles if there are enough road patches for one turtle to; B( q C( O, t7 {9 T6 p3 k X
;; be created per road patch. Set up the plots.
' y% |( ~% h; k3 j. Gto setup: F! C1 X. T# Z: d, _
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setup-globals& g5 y6 }% N: r, ]3 N% E- \
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;; First we ask the patches to draw themselves and set up a few variables* D4 q8 y8 R3 K# i! Y
setup-patches2 L9 c& r9 a2 p" k( ^
make-current one-of intersections
' F" Y8 x9 Y4 z' H label-current
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; M/ J: b- J/ v; O3 k set-default-shape turtles "car"
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6 B& {; F) n- c, F/ _+ h if (num-cars > count roads)
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2 ]' h7 A& G& T user-message (word "There are too many cars for the amount of "
8 q Z# h! s/ P "road. Either increase the amount of roads "6 q, E. ?* \* T& I0 x# a
"by increasing the GRID-SIZE-X or "
9 P* a: A$ w b" i+ r u6 W' p "GRID-SIZE-Y sliders, or decrease the "
4 R& k1 j+ I7 M "number of cars by lowering the NUMBER slider.\n"5 Y* G7 S% ?# k& v9 ]8 n" a
"The setup has stopped.")
- o8 H" O7 a7 _ stop1 W& R2 ]- A- ?
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1 o" h7 F+ }; E% e$ } ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color9 p- m( X8 H$ e/ F2 D3 q" R" q3 _
crt num-cars; g2 m6 k: w3 Z" y& L' q0 y
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$ d7 O6 G- k2 Y+ p7 x7 S setup-cars
/ S/ D. j6 H* A% C! B0 F2 B set-car-color
% A4 j6 C/ P/ ~0 i' c1 |4 R record-data
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;; give the turtles an initial speed$ ~$ \( h$ H$ u, ^1 a
ask turtles [ set-car-speed ]
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reset-ticks
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% A3 C6 Y/ d* i$ y. s% A;; Initialize the global variables to appropriate values
2 S5 h. K/ z9 ]$ f; b/ vto setup-globals
; \' |% s' U* d# _ set current-light nobody ;; just for now, since there are no lights yet6 Q2 n x' ?2 l0 x
set phase 0
& v$ _- m. [* d* t+ k- H& l set num-cars-stopped 0
- G) S+ {+ O; \ set grid-x-inc world-width / grid-size-x
" ?- ]$ A' j/ T9 p. C+ B1 w9 A set grid-y-inc world-height / grid-size-y0 D; C& J/ \# x& h5 T0 H6 Y4 {
. T/ ^2 }( {4 h5 r; z5 n0 p: ` ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
0 i! Q0 X" Z' ^- w3 ~7 s* u set acceleration 0.099
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# f! ~8 y$ E% T" t& K5 @9 P;; Make the patches have appropriate colors, set up the roads and intersections agentsets," J. y7 ^& |: }
;; and initialize the traffic lights to one setting5 b0 X4 } V5 w8 _/ e
to setup-patches
; \" Z9 G! R. D$ A9 `3 _' E ;; initialize the patch-owned variables and color the patches to a base-color8 }% ^& d! f- L9 ]! n6 \3 j3 H
ask patches! Q' ~$ O: R4 k, o
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set intersection? false6 P8 M+ d' F* P9 C& z
set auto? false( a2 d+ E2 t: K
set green-light-up? true
- O0 c5 A4 F$ t p) n4 a set my-row -1! }$ s+ I! a* N9 j
set my-column -1
+ S# k$ _1 ?$ M: O set my-phase -1* l; U* P Q/ ~6 `8 U. y; {
set pcolor brown + 3
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0 W8 p5 f9 o/ D% q- q ;; initialize the global variables that hold patch agentsets
. S& d% F7 \ m$ M' U/ Y- ^ set roads patches with( i% c/ i1 V5 r
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- `; \6 w1 d$ Q0 t7 g& M# V5 W
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 ^' s' h/ ^: ~- k3 [; ]4 k
set intersections roads with) d! `& R( L1 i3 O- \/ \
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
3 q: c- b3 J0 u, } (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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8 F- r$ v3 S; K) e; _ l+ R0 J ask roads [ set pcolor white ]
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end
' v# r7 S3 V: ]; T, g: t其中定义道路的句子,如下所示,是什么意思啊?! [4 S8 f& ]% f) N& ?: r
set roads patches with7 c$ e$ m8 n9 Z1 L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, a; J' k4 B- W. \6 P
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' O7 ~* j5 u6 `8 Y" F+ 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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