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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。
2 Y/ B: l" e2 X2 p/ unetlogo自带的social science--traffic grid这一例子当中,) c! S& B+ J( O' i' r
globals
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! I0 j; h, m$ h6 S) ~ grid-x-inc ;; the amount of patches in between two roads in the x direction: f# K/ c2 [9 _6 b$ ~5 u
grid-y-inc ;; the amount of patches in between two roads in the y direction4 `/ f) m1 q& s0 R# m8 W( P
acceleration ;; the constant that controls how much a car speeds up or slows down by if6 S' ]: ^& }( }* v: K/ R
;; it is to accelerate or decelerate* m, v+ Z- {) ~3 T7 `8 h f
phase ;; keeps track of the phase, v) Q. ^5 m$ A% F- \
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
/ D5 L$ L0 Q6 `+ K$ J current-light ;; the currently selected light
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" q, w D. a$ \1 p# S" R h$ r j! ` ;; patch agentsets9 e2 U/ e; {5 s$ H, R
intersections ;; agentset containing the patches that are intersections
$ r+ T. U) N1 q+ J0 [ roads ;; agentset containing the patches that are roads
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+ O. C5 U8 V. T7 J! Kturtles-own
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2 x% n+ U: o' K4 g speed ;; the speed of the turtle
' h+ }7 H1 T' F% b0 h up-car? ;; true if the turtle moves downwards and false if it moves to the right/ c! A# Z/ g- M
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own+ K5 U4 |# c1 W- x; e, N
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intersection? ;; true if the patch is at the intersection of two roads1 x. Z L& {# s, ^/ r
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
# E5 l0 W" F1 T ;; false for a non-intersection patches.
; H. P$ L. }' x7 M my-row ;; the row of the intersection counting from the upper left corner of the
) G, z7 }7 N' n- J2 i" z& {3 |( I ;; world. -1 for non-intersection patches.: u R" G; l5 C
my-column ;; the column of the intersection counting from the upper left corner of the
- H( V8 z h3 A2 m' B2 `" o ;; world. -1 for non-intersection patches. J& M' _" }* a
my-phase ;; the phase for the intersection. -1 for non-intersection patches.5 X) P" E# }- o$ S) p [% ~
auto? ;; whether or not this intersection will switch automatically.$ `; G* ^+ p) I5 [7 P
;; false for non-intersection patches.
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& C" T9 G0 E# l;;;;;;;;;;;;;;;;;;;;;;2 L% I# E; y F' `3 A$ S' ^
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
J7 z, X% ^& g7 x# }* V; g;; Create num-cars of turtles if there are enough road patches for one turtle to5 b5 P9 ] U' D) Q7 z" c
;; be created per road patch. Set up the plots.) z: d1 }8 `" N% N2 s
to setup
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# d* z9 t) g) X" s: I7 y3 k5 k0 x+ n setup-globals+ d8 T$ e! l2 Z9 Q
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;; First we ask the patches to draw themselves and set up a few variables
( Y. |, }9 z0 I9 o/ ~8 c# a' U3 q7 M setup-patches; n, g! b" j6 @, c2 g
make-current one-of intersections+ P$ F. {% t3 o0 c, J
label-current$ F1 _7 y) A+ c7 W4 |0 M/ N" V
: E& M p9 U' Q! k: v- W: F2 R4 w0 a | set-default-shape turtles "car"1 z' j- e' t4 n
# D4 {' K1 P) ~8 v1 w7 h if (num-cars > count roads)/ g* w+ A. }) \) L3 A
[
2 e" H$ Z/ H3 A) f: @ user-message (word "There are too many cars for the amount of "
/ s2 D3 o6 p0 y/ j+ { "road. Either increase the amount of roads "
8 S/ m: b! F4 m4 B1 @ "by increasing the GRID-SIZE-X or "
) c1 i: F5 d$ ? "GRID-SIZE-Y sliders, or decrease the " i) Q, F- j* _8 C# S9 k( |
"number of cars by lowering the NUMBER slider.\n"2 ~- R% x& `9 W; I1 Z
"The setup has stopped.")+ N4 K. f% N) |# `% z+ |; W
stop
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/ @( d3 r6 u/ Z; C' c4 R% G ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
8 g" b$ T: f1 m" @ crt num-cars/ m" Z% o* ?# Y% ~6 _
[
/ ^8 ~# v& C$ ]+ J6 S setup-cars
/ f7 S$ \& Q3 u& s/ M4 w$ w set-car-color
! C7 B( e' I$ G' A. ?" {6 a# b record-data
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! ]3 N5 i9 z+ W( i" t% h' v ;; give the turtles an initial speed0 x+ [7 y H J
ask turtles [ set-car-speed ]' C$ y# L6 A& c# F: P+ y
5 i. j* x# o+ |! K1 A reset-ticks D& q, X" U2 S: l
end
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;; Initialize the global variables to appropriate values
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" |2 r( F L/ C& q set current-light nobody ;; just for now, since there are no lights yet6 v- H+ l( ^$ X3 q6 E" d0 T1 N
set phase 00 B9 v7 Y( X+ u5 u0 l
set num-cars-stopped 09 G' M. s" m% A, Y& Q$ M
set grid-x-inc world-width / grid-size-x
$ p5 m# D. m& v% p set grid-y-inc world-height / grid-size-y* D2 ~* ?4 M* ]
0 Q0 w& d+ G8 w5 z( V' R ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
3 t: m/ x" q: R3 f0 Q set acceleration 0.0993 p6 C9 m: |2 V4 j
end
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$ Z3 _" I( [* z* p1 [- ?4 H;; Make the patches have appropriate colors, set up the roads and intersections agentsets,; E G5 E& ]( @" C8 u( X8 i+ V
;; and initialize the traffic lights to one setting& K$ n# b$ \. C9 ]$ U
to setup-patches
5 x$ [; E. ?$ i. |" T0 Z ;; initialize the patch-owned variables and color the patches to a base-color% {* F; X) [# c8 ]
ask patches# ^. d9 K( L7 k U" }/ q
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set intersection? false4 M: m$ w' m$ r X9 p. z& h
set auto? false ~# s5 G2 Z- h: Y% r
set green-light-up? true: Y( y+ R( E+ ?7 w" p
set my-row -1 |0 h3 `: \+ C7 o
set my-column -1
' Q. F: c2 h" q1 O0 h% G set my-phase -1( O* S, U0 A* C2 T( ]2 U- H
set pcolor brown + 35 f. U8 N. G$ E: S1 \+ V$ @
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# ^+ o4 ^0 M0 c3 o( K8 V. q ;; initialize the global variables that hold patch agentsets4 m( A; a9 f) w6 E' i& S; R0 A
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]. l D' C8 Y* A9 r8 ]2 ]0 p- X8 w% ]
set intersections roads with
. ~: @, V* {: B5 M+ J8 @! W( Z$ y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
7 s! {$ p3 ~' I (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; i" X# }1 M. }0 ~
' M0 y% j8 T3 h) Y ask roads [ set pcolor white ]
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end* J0 x9 h& \4 Z* _8 G
其中定义道路的句子,如下所示,是什么意思啊?* }* l+ X* B2 x& K' O8 A$ S! l
set roads patches with7 N5 s ]& s. ], c" U n) e
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% G7 ~& d* a" b8 j1 P# r2 E
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 o" C8 ]% J2 p- A4 K+ ~5 q+ N( z7 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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