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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。
. Y) ?2 x" U% x' @3 S) Ynetlogo自带的social science--traffic grid这一例子当中,
, R6 d' w# }, r5 Q a* Q; ?: Eglobals
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( i$ k" s5 v- c grid-x-inc ;; the amount of patches in between two roads in the x direction$ s& N1 w7 e. v/ p5 X4 t
grid-y-inc ;; the amount of patches in between two roads in the y direction
$ M5 s! G+ n( O acceleration ;; the constant that controls how much a car speeds up or slows down by if
5 {* Q3 x4 r9 L ;; it is to accelerate or decelerate, s' ?- z' {* D5 V8 o; h5 ?
phase ;; keeps track of the phase: U/ K& [$ ?9 T) j
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
; Y- \+ r- v: O' x current-light ;; the currently selected light
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;; patch agentsets
$ `) a- _8 V6 x! j intersections ;; agentset containing the patches that are intersections
) k3 F9 X# O i' |. S5 X8 C roads ;; agentset containing the patches that are roads6 a, b7 X7 O6 D
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turtles-own$ f8 Z8 ^8 O. H J
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speed ;; the speed of the turtle$ r8 K' A* f8 x; ^+ _- p
up-car? ;; true if the turtle moves downwards and false if it moves to the right
% t3 \, ~ v' A* m0 O+ ^) h8 J wait-time ;; the amount of time since the last time a turtle has moved8 J: M! _) m& W( B- Y1 M
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5 }6 W& @( ?0 R3 V, e2 upatches-own6 ?6 o+ r" u1 g( G7 a
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& p9 ^( f. s9 M5 d' O intersection? ;; true if the patch is at the intersection of two roads
% ]0 h; G% A1 L green-light-up? ;; true if the green light is above the intersection. otherwise, false.
8 m/ a* }& M1 T& j. V ;; false for a non-intersection patches.
; E2 O2 {3 p9 H& }0 `6 N my-row ;; the row of the intersection counting from the upper left corner of the$ Y! D% m1 p& A) k$ w8 \* X& [
;; world. -1 for non-intersection patches.
0 o1 k4 n$ i; n. V8 { my-column ;; the column of the intersection counting from the upper left corner of the% b, d3 |. b% f, W3 Y: M1 }$ T
;; world. -1 for non-intersection patches.
V1 p( b) R8 b! f# K1 I my-phase ;; the phase for the intersection. -1 for non-intersection patches./ n, y8 s2 a% s. k9 f" {! M4 J
auto? ;; whether or not this intersection will switch automatically.
# t4 [6 g: V3 ]5 A# _6 Z m- |2 J4 S4 b ;; false for non-intersection patches.2 _. Z& }* Q% R4 R
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;;;;;;;;;;;;;;;;;;;;;;3 e" o: p# X2 j r! J# m
;; Setup Procedures ;;
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8 v7 D4 h3 Q" u% T+ l; K;; Initialize the display by giving the global and patch variables initial values.
- |% c+ o4 {- P;; Create num-cars of turtles if there are enough road patches for one turtle to
% B- F0 G6 J& e* `;; be created per road patch. Set up the plots.
4 V# t6 b" ]7 ]to setup: F3 b* b% y9 Y* M4 |4 P' v( a
ca
% ^$ d4 n7 j) \ setup-globals
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2 i, \# _9 C& v: e ;; First we ask the patches to draw themselves and set up a few variables& F% ^4 ` M8 ]* I
setup-patches" O4 t9 s5 K) b% Z# }
make-current one-of intersections
6 D9 P+ t2 F# {3 L9 y label-current
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set-default-shape turtles "car"
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5 Z% }7 Z8 S' K3 @3 \; n# C7 v7 E, D if (num-cars > count roads)
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9 u8 F% A2 L8 G& \. S6 e user-message (word "There are too many cars for the amount of "
b- V! R+ Y/ \- j- ]( b "road. Either increase the amount of roads "% d8 H4 a% T# q% Q
"by increasing the GRID-SIZE-X or "
# x6 o; b& M! e' V "GRID-SIZE-Y sliders, or decrease the "
R! d: W; l: D' H! U9 U( V3 ? "number of cars by lowering the NUMBER slider.\n"& ]9 L+ n9 h% G+ o# E( I
"The setup has stopped.")6 ?. _1 s7 [; H0 |: J
stop* z" {1 _+ t/ E) N4 ?$ M' Y
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( D" {. n! P- S' A: Q ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
4 Y9 _; C0 i U% Z* Y crt num-cars: [* K! F9 Y3 I6 A& A
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. L& w1 J' {* v setup-cars! e2 C0 f& J9 _2 t
set-car-color: }5 L7 S+ K8 Q% x: _/ p
record-data7 Y! d q. p8 U% @* J. P$ V
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;; give the turtles an initial speed
u2 t4 W; x$ e# z8 J* `1 v ask turtles [ set-car-speed ]* B* O. J8 R9 Z% I2 o: Q
. I) \0 g6 H# \# _7 L P reset-ticks
' I/ V' O$ C- G7 U6 C. g4 {end
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;; Initialize the global variables to appropriate values' F% C1 N1 y" J+ W8 d; m9 t
to setup-globals
! k7 @0 O% s: c8 @* s. m# v set current-light nobody ;; just for now, since there are no lights yet& ~; w% m: E: z* T5 p' }% [
set phase 0
! V( f1 P3 Q; y. I$ H9 U set num-cars-stopped 01 i# D( L, s, q! D/ s
set grid-x-inc world-width / grid-size-x
& }: h/ M, W/ y8 g set grid-y-inc world-height / grid-size-y
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) s6 l* g8 L0 A# L ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
o. v! G* k6 ?' C3 A set acceleration 0.0994 f2 b/ i+ k0 D) I# p8 A4 W* x
end3 r2 l' }1 C. W
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,* n" i% y; c+ G: R; c" q: f
;; and initialize the traffic lights to one setting
( O! e7 j, H! Z+ pto setup-patches* Y7 W. ]5 {6 k' A, `& H
;; initialize the patch-owned variables and color the patches to a base-color
1 y$ v9 l9 Y, @# n' v ask patches
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|5 p: X! m! c" h' [0 t) o3 U set intersection? false, h' F) W x& ?# t8 f; w8 K
set auto? false; r: x3 r7 O$ C8 R% B
set green-light-up? true- u( i) a9 I, _# F: O+ G7 t
set my-row -1
; N/ n' h. R# z$ e set my-column -1
8 F1 u4 \4 J: z set my-phase -16 E& |# t; i) \* z
set pcolor brown + 3+ ^& H: l5 {4 m) a$ k
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;; initialize the global variables that hold patch agentsets
8 @6 x! i* s, Q- X+ y# w6 k) A set roads patches with7 P1 L8 S# t/ n y ?# d
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 o: V( |3 @# Q" l: @2 t, P j
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ K2 k0 q- _5 m5 R6 Z, s
set intersections roads with1 ~( z2 I5 j& P0 U5 j8 [7 F& L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and w* g& r: B7 s; u2 N
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ A/ M9 P/ A! l
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ask roads [ set pcolor white ]
7 O* L7 h0 V/ c+ |" @1 B setup-intersections- j, ~7 ^ y- x: y5 N
end
9 U, V0 F6 F* D* b其中定义道路的句子,如下所示,是什么意思啊?/ E' m3 P0 n: v6 _7 y* ? W2 Q
set roads patches with
: r3 B7 T& U. t& j" t% `) J [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! z2 Z9 I. S- |+ } (floor((pycor + max-pycor) mod grid-y-inc) = 0)]. m2 b( g4 R. n" W: x; e0 X. _
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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