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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。
- J3 H0 p2 R' o$ t" A" Y& n, {- knetlogo自带的social science--traffic grid这一例子当中,+ Z4 H" F3 V% H1 s' L* q8 t
globals
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3 K/ Z d' F& K$ |) o grid-x-inc ;; the amount of patches in between two roads in the x direction, i2 l7 ~* p* V. t4 ~% i$ _
grid-y-inc ;; the amount of patches in between two roads in the y direction5 \5 Y, V" u1 r* t. ?6 ?
acceleration ;; the constant that controls how much a car speeds up or slows down by if! B! ]; h6 r) s9 b: x
;; it is to accelerate or decelerate7 l& K% m7 i" u
phase ;; keeps track of the phase
' s V# r1 c7 Q' }% a: d num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure8 ?- R s J6 T9 \% L4 |- f2 q
current-light ;; the currently selected light! P+ Q) T/ `; B( x) Y8 \6 I% {
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;; patch agentsets0 ^) B0 Q. S \2 l, a- f4 ?
intersections ;; agentset containing the patches that are intersections
1 `, p& Q! X9 l roads ;; agentset containing the patches that are roads
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turtles-own% a7 L! l& u- c9 M8 f+ }9 V
[
; O4 p# C2 d: t# Q" p speed ;; the speed of the turtle, y2 x3 w, l5 G7 S4 _/ r9 h5 ]
up-car? ;; true if the turtle moves downwards and false if it moves to the right0 K, {- i0 ?2 ]% K5 a& G4 f" ]4 ~
wait-time ;; the amount of time since the last time a turtle has moved
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o. L1 N7 Z; ]6 Bpatches-own
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; s/ v! k* a* [2 N" N# `% o, X% U# M0 l intersection? ;; true if the patch is at the intersection of two roads
8 K J3 r& h( u' Y green-light-up? ;; true if the green light is above the intersection. otherwise, false.
- X8 [/ N0 |% k8 W+ f+ S ;; false for a non-intersection patches.
8 j# v5 _) U! |/ y4 `0 q2 E my-row ;; the row of the intersection counting from the upper left corner of the
8 v! Z2 ]( r$ ?4 [8 N ;; world. -1 for non-intersection patches.
5 z& R+ |; _+ A& I8 R my-column ;; the column of the intersection counting from the upper left corner of the
; H* Y; K1 _0 g6 x# }' {0 r ;; world. -1 for non-intersection patches.
/ c" K+ f/ e1 h3 @8 U$ r5 K my-phase ;; the phase for the intersection. -1 for non-intersection patches.
# U; K) Q) E& u, z+ B( r auto? ;; whether or not this intersection will switch automatically.3 `2 u# h6 K2 ^3 ^
;; false for non-intersection patches.
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5 \. w7 [$ w9 q) b9 F& Z7 J;;;;;;;;;;;;;;;;;;;;;;
& l& G' l% H) J5 h/ u;; Setup Procedures ;;
j7 I5 f* ~) G; n;;;;;;;;;;;;;;;;;;;;;;- A3 x! N8 o1 g7 L, B8 B z( T
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;; Initialize the display by giving the global and patch variables initial values.
) s _: h1 L; k) ^$ a;; Create num-cars of turtles if there are enough road patches for one turtle to
% m3 N% |9 T Z' O;; be created per road patch. Set up the plots.
& U% C7 F; d3 J' _5 B; sto setup
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. d4 J! e; y0 }0 O; K setup-globals
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! T7 E2 C# k# b# ?; ]* ~1 i5 K ;; First we ask the patches to draw themselves and set up a few variables
: I2 @$ P# [, n; L+ d setup-patches
* ~4 E3 S2 {: ^2 O8 f- R, n: J make-current one-of intersections
; c0 D! l; R5 k0 s0 F label-current
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5 w6 _7 N5 G S) F) _ set-default-shape turtles "car"
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' \/ a# I5 ^2 N* Z& [2 D- _9 e2 X if (num-cars > count roads)% U# e C3 T% R* h; S
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- }. A, g1 J& Q, b9 _) V5 ? user-message (word "There are too many cars for the amount of "
/ ] \* w: p" Q5 }9 A$ V "road. Either increase the amount of roads "
I6 q7 d, ?5 M% g: l "by increasing the GRID-SIZE-X or "$ {8 ]" J) H+ n9 n1 i/ O( @
"GRID-SIZE-Y sliders, or decrease the "
) e' Z) Y, |6 A/ d! A "number of cars by lowering the NUMBER slider.\n"! g% ~( x& H+ J" O, ]
"The setup has stopped.")
7 I! G( X8 V& f+ q stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color; b% c, j% Z s$ w1 _
crt num-cars7 x2 ^, |, J+ X4 L% [
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setup-cars
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record-data
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1 c& q( ]' c) l, A5 Q% r. V' K ;; give the turtles an initial speed
0 x- h! b* }$ |/ ^7 n ask turtles [ set-car-speed ]
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) ?( C9 E, r+ I0 Z9 O; O reset-ticks: O3 N* @; {7 ? P& H8 k8 M6 [9 I
end7 @0 K s. y% g! _
! Y5 t u) R: c; T; d7 M9 K' l' h;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet0 u5 W; U7 W5 O/ C% B: f
set phase 0) P* d T0 x5 C, } m
set num-cars-stopped 0& _& O9 [. L& t
set grid-x-inc world-width / grid-size-x
- M. Y7 \# |' {& s& g3 _7 G4 D set grid-y-inc world-height / grid-size-y
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- {, k/ C C {* {, D# z3 o ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary* `* p4 F" F, ~5 w, w
set acceleration 0.099$ e3 K, j, ^5 O8 n& B2 ?
end6 d0 F6 A5 \: O! p2 \0 [$ O& W
8 [* {1 g7 x3 q3 { E;; Make the patches have appropriate colors, set up the roads and intersections agentsets,* ]6 \1 R' N0 G# L
;; and initialize the traffic lights to one setting
9 Q6 R% t2 X! L6 Nto setup-patches& y( R6 r4 `( e7 E$ S! t
;; initialize the patch-owned variables and color the patches to a base-color+ N" X+ X! v0 G" f' R" U9 C' \$ y
ask patches, ]- Y! Y1 @- v) _: J
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I" Z& u- Z$ R% i set intersection? false3 F0 B' o* ^& s) ?" ^
set auto? false
+ q9 \1 U5 v4 @5 _, i5 h set green-light-up? true+ Z7 Q# T! E9 }5 k
set my-row -1+ h2 e/ V8 ^& ]6 ?+ k8 p6 |
set my-column -1
: X7 ]1 _" T& f4 S0 C set my-phase -1& o6 w, M2 O, k9 v* o9 b$ ?
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
; E* Q" r7 l" M9 I set roads patches with& C+ Z* g, J1 i9 H/ w
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or& q7 a- A, t k2 d
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 U5 k( H/ F' l+ E" x1 |: S$ K
set intersections roads with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]1 t# ?: M4 V) U; d* T0 D2 ^
setup-intersections
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' i- c2 ^3 T) |4 w' S其中定义道路的句子,如下所示,是什么意思啊?
) O) ^; @8 y9 ?8 E/ d. }$ X set roads patches with
* x' Z4 ?7 G5 ]4 R [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 h& k% N' ^: j9 I% W0 ?7 E
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) ~1 C$ K* k1 t: \- j+ c5 m& U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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