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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。
$ l2 C+ X" r+ Pnetlogo自带的social science--traffic grid这一例子当中,6 V% H; ?! E" |5 j; A! @' |3 J
globals
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) W4 a0 y$ O8 O. A) \ grid-x-inc ;; the amount of patches in between two roads in the x direction
" T% d; p1 s) d3 D grid-y-inc ;; the amount of patches in between two roads in the y direction
3 _" y& z7 {4 t- n0 w, L" f6 |! Z acceleration ;; the constant that controls how much a car speeds up or slows down by if7 D ]( t6 d9 u
;; it is to accelerate or decelerate% }8 i+ l+ m$ Z4 ?
phase ;; keeps track of the phase
: _; [% m; \8 R8 c1 q num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure4 ~- b/ I$ E" G( H+ c
current-light ;; the currently selected light# ^* K; W R- f; L
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;; patch agentsets. }0 B9 T ~" o: d3 l3 ^4 R
intersections ;; agentset containing the patches that are intersections, K4 P: ~4 K: B u" ?. K* R
roads ;; agentset containing the patches that are roads. M* B4 G+ }* N9 A) G9 Y; g
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$ |* f; L7 [: W: l F6 O7 tturtles-own
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5 j1 f) Q0 R3 w6 m speed ;; the speed of the turtle
. M, e4 I6 B. F `6 x$ e6 R( H1 p up-car? ;; true if the turtle moves downwards and false if it moves to the right
. B) f- e8 q- b+ U( A wait-time ;; the amount of time since the last time a turtle has moved
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patches-own) j5 R$ M4 u" X8 i8 O2 y
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intersection? ;; true if the patch is at the intersection of two roads+ D0 H9 n2 P; _* L2 I* P/ b
green-light-up? ;; true if the green light is above the intersection. otherwise, false.- ?5 n! W1 a" E8 d3 T
;; false for a non-intersection patches.
1 L% d& D% [; ]0 r% r my-row ;; the row of the intersection counting from the upper left corner of the. T9 b! e4 x0 b7 p) C
;; world. -1 for non-intersection patches.
2 W S: Y7 j1 o! O# r$ a my-column ;; the column of the intersection counting from the upper left corner of the
' e( o- u* X7 z; } ;; world. -1 for non-intersection patches.- U4 B+ x- x# t6 e7 W y
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
, T$ T& F2 u$ V& I* u0 L auto? ;; whether or not this intersection will switch automatically.2 E+ j( \+ q4 Z* _# |% _. A
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;3 \# M: L$ g9 s$ I% c' o3 q: p
;; Setup Procedures ;;( Q4 s5 U# c& x$ O5 Y! H7 M, V
;;;;;;;;;;;;;;;;;;;;;;) h% g; M# B( y/ E; v2 t/ c6 b' b8 w
# K: B& }9 {4 X2 f8 V0 F;; Initialize the display by giving the global and patch variables initial values.7 B- r1 r6 p! o1 N# }) J
;; Create num-cars of turtles if there are enough road patches for one turtle to
2 ~) ?- q- O8 k- i;; be created per road patch. Set up the plots.5 A" u, }$ U c3 y! p' j
to setup: j% f' J( x2 Q/ T$ S2 |- N
ca
% S! |) d* ]7 m, i0 N setup-globals+ |) B4 }1 K0 t" L$ B) V
" A/ i& P. |0 N% Z) |3 x; m ;; First we ask the patches to draw themselves and set up a few variables- Y7 }# V" t+ g) [! m
setup-patches0 }' |* ~8 Z3 Z3 {! X8 d$ ]
make-current one-of intersections6 o) Q5 j1 A; F
label-current5 N& ]8 s+ a: G' R' o
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set-default-shape turtles "car" I2 }$ M1 H4 Q, t( y- i
9 f* Q6 J( @" J# G( H Y, [( L2 H$ L if (num-cars > count roads)- r* p1 T- J0 W8 r; J: H4 A& S
[
, Z" ]5 k' f8 K) X) T3 q# x* b$ c' Z user-message (word "There are too many cars for the amount of "
3 t8 m W6 u+ z2 X+ T7 k1 n% @ "road. Either increase the amount of roads "$ H: e3 x' z1 {& ~
"by increasing the GRID-SIZE-X or "
; ?! i2 k" a8 J. b) l. O: U( f "GRID-SIZE-Y sliders, or decrease the "
7 |9 h" x2 Q5 x, m3 K7 I O1 @; T# g "number of cars by lowering the NUMBER slider.\n", A# u) L! U8 `* p
"The setup has stopped."). J4 {- V# W+ u5 u- X8 R* x
stop
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" u$ z# V3 N2 W& ` ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color' l# _' ]- w/ L+ r7 H
crt num-cars% g0 h/ q) j+ ^ v
[
4 @( R0 v$ t u: h, i7 a setup-cars
: x/ {5 o2 j: [- z- ?4 n1 [' j. e* X set-car-color
/ b* p7 i Z! J8 O3 B record-data
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;; give the turtles an initial speed
& i% I# @( B$ J6 ]- G ask turtles [ set-car-speed ]1 F; G" J% C$ [; f$ _6 C& v- x: \
6 c8 ^8 N9 t ]9 S G1 P; f1 n" V reset-ticks: ?! J: U% P' b9 Q3 H
end
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3 `7 t7 I# S: z;; Initialize the global variables to appropriate values5 j/ N) i* U. x
to setup-globals& K# Q* ^8 N$ k
set current-light nobody ;; just for now, since there are no lights yet2 ?# s' J- S% U* g+ X, V0 s
set phase 0
9 m+ l9 p; h7 r- s0 w set num-cars-stopped 0' X. b. `1 l' }8 u
set grid-x-inc world-width / grid-size-x. ?( |# H+ t- N+ N8 D1 x+ c4 m
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary( _: t' ^* B/ i! T
set acceleration 0.0990 n O" K8 |+ X: M6 Z7 E
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
?# r+ l' J& l- O& o/ ^;; and initialize the traffic lights to one setting% I0 U$ X1 G) v/ j
to setup-patches
I" |' Z. E) h1 A5 I) l3 r ;; initialize the patch-owned variables and color the patches to a base-color8 d$ l( d# s& Z n: s* p+ P
ask patches/ _1 D' C5 B5 h% u8 l
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set intersection? false
$ `8 s5 {/ ^1 U& X set auto? false' s" x5 \! C- M# q: z
set green-light-up? true
* A" o$ B& q2 i L7 v/ r set my-row -1$ S0 o8 n) v8 G D* P1 L
set my-column -1
) _8 d2 ~# P2 i8 u' v+ @ set my-phase -1
- {- h0 Z( @! j, X, P& J4 X set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
; i: i5 S! h u% v% y, H; `: P8 F: ^ set roads patches with
& @1 f9 T, d @+ L( @1 L [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
4 \! ^2 ~! F: Z9 o2 ]1 U- u (floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 ?+ x/ q& a# [. z8 l' x
set intersections roads with
( h1 j9 n; D# K" A8 ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 X; A" y- a+ s# t! ?; e+ ^/ u (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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end+ i$ r' b1 J6 o, X
其中定义道路的句子,如下所示,是什么意思啊?
8 o7 L* p% V4 w+ N4 z$ Q6 e set roads patches with
1 V: m% ^4 w% X* X0 n [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; T- W4 w3 F. F
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]& U; v, f1 ~! K$ M) Y
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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