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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。: O e L1 g" z* ]5 U. L
netlogo自带的social science--traffic grid这一例子当中,
) S' q4 a0 f8 B0 ~6 Cglobals
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* [; n0 Y/ V1 C4 {3 q grid-x-inc ;; the amount of patches in between two roads in the x direction( i! H; }+ H+ E5 N- l2 ~+ z) G+ l
grid-y-inc ;; the amount of patches in between two roads in the y direction
# p( w* @0 M7 z i acceleration ;; the constant that controls how much a car speeds up or slows down by if
" B* e8 v" e0 q6 O4 i ;; it is to accelerate or decelerate" U8 @& r4 E# N' C& m: a
phase ;; keeps track of the phase
5 l6 O8 B4 r q" b2 | num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
& `( S) V& k$ \' k current-light ;; the currently selected light( ^$ C |5 | T( p$ [
/ [- O3 p9 [4 } ;; patch agentsets4 t" H. ~& y3 f) C
intersections ;; agentset containing the patches that are intersections
8 s. C9 q& F1 @6 F roads ;; agentset containing the patches that are roads
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turtles-own( Z; N' Q- |1 J( f; j
[
& x( \/ s$ R0 [+ _5 f2 o! t8 H speed ;; the speed of the turtle
; e& `9 j8 R2 c3 M$ D) g up-car? ;; true if the turtle moves downwards and false if it moves to the right4 G" x9 j; G6 n2 k7 ~
wait-time ;; the amount of time since the last time a turtle has moved
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" R& R Z4 |) w8 {! |# zpatches-own6 y7 F/ [6 a1 b3 t8 Y2 }
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intersection? ;; true if the patch is at the intersection of two roads; r6 L( k: x3 Q% X/ ?- ?9 v1 R
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! e! J. M* a( p2 z B( t2 L ;; false for a non-intersection patches.0 z4 t. q4 k/ M
my-row ;; the row of the intersection counting from the upper left corner of the
" C$ y% v `* b# C: i j ;; world. -1 for non-intersection patches.
1 ?9 U- r3 C+ d: a my-column ;; the column of the intersection counting from the upper left corner of the& W, e6 k' s, I# K3 e1 M8 _
;; world. -1 for non-intersection patches.+ _. O: ?# \- E0 `/ b
my-phase ;; the phase for the intersection. -1 for non-intersection patches.% k$ p+ b! X) a
auto? ;; whether or not this intersection will switch automatically.
0 O+ g* J( n# S; N5 _ ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;% u% F' ~$ o7 W* U. y
;; Setup Procedures ;;
5 I- x [2 o4 Z H E' l;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.0 [3 y* r6 C8 ^* r7 h5 P, }6 `& u+ I/ h
;; Create num-cars of turtles if there are enough road patches for one turtle to
& Z9 s) `% @1 _3 ?;; be created per road patch. Set up the plots.9 b) F7 z5 p- b) ?) J
to setup
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: x9 |7 \6 A/ \* L setup-globals
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;; First we ask the patches to draw themselves and set up a few variables! c) S! \* o; z; M* r9 J
setup-patches: F" O& c7 I" h5 l
make-current one-of intersections
8 _! @4 ~7 C9 | V; W2 g5 k7 z3 H label-current
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set-default-shape turtles "car"" i2 M5 A. w6 @9 D1 t; X
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "! l: d/ H' Q, l4 h2 }7 |$ s
"road. Either increase the amount of roads "6 O$ b% h" ^0 B% {
"by increasing the GRID-SIZE-X or "1 z: H2 {0 s6 T
"GRID-SIZE-Y sliders, or decrease the "
2 G3 N" o9 p, K0 R1 k E* y "number of cars by lowering the NUMBER slider.\n"
( `9 \# R$ V9 U+ j" {. d0 @ "The setup has stopped.")+ l# V$ r/ @) c6 q
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color' |' g! E) b! u0 I R3 Q b
crt num-cars
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setup-cars% }4 `+ |6 w$ D T* J# w
set-car-color
+ d5 Z4 E7 d) Z. e, ^ record-data# \2 q. h' j9 T+ j
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;; give the turtles an initial speed: a( U$ I5 A! G8 x6 {+ x
ask turtles [ set-car-speed ]: i% n! \# b* [9 p6 o* r5 Y9 c3 C# x
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reset-ticks
* G* k. [. j% `0 V& mend
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;; Initialize the global variables to appropriate values
L/ P- p- ~, M; Z9 j+ I1 O5 R% fto setup-globals; K- c k( d4 M4 g
set current-light nobody ;; just for now, since there are no lights yet
$ v/ C# y& F2 `' ^2 w' e' x) a set phase 0
+ l- S; e1 B, k# ~5 m set num-cars-stopped 0% h' G6 H. {8 Q9 O6 f" r
set grid-x-inc world-width / grid-size-x
E* I: y8 }! I" B. O# \2 R4 g8 y# p! O 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
1 j0 {2 F8 ^2 H0 S2 P) N0 r set acceleration 0.099
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' [$ h7 D: x' ~/ ]5 c;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
) q3 K" Y& E7 `- w$ a6 T9 f;; and initialize the traffic lights to one setting
) ?9 p$ v* W8 C5 c- Yto setup-patches
# o6 J5 Z) X# }8 [, y$ D ;; initialize the patch-owned variables and color the patches to a base-color+ [! d' A ^0 l* r
ask patches
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set intersection? false2 d# I5 f1 I3 V7 _: R8 u% \
set auto? false# ?7 @9 W: i/ t. b# B
set green-light-up? true! D; P7 n+ e7 ?7 q a: z5 C
set my-row -1
# u7 {2 y% i. ~& n0 U8 J set my-column -1
7 e) L* M- |8 ]& G) V6 W" H0 H set my-phase -1. g+ K0 v0 n4 U8 h( {! O4 y. f
set pcolor brown + 3
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: P, F5 f0 D2 D& u4 K% ~ ;; initialize the global variables that hold patch agentsets
1 \$ z" t4 m9 ~" Z6 Q. { set roads patches with# y/ W, _( m( T1 L, W- U& s
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! M7 z( Y0 \/ W: m
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 K5 r' a. E* Y" J0 Q set intersections roads with9 M" Y! Y4 e+ `$ I
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and( I! @- B( u" j" D+ x/ U. b5 E
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 A K" G7 _: p3 {
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ask roads [ set pcolor white ]
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$ C7 d4 x0 R! Z4 E6 i" ^8 |: \- |end
3 ^4 v/ r0 ~- {# i# s. n2 g% L其中定义道路的句子,如下所示,是什么意思啊?
* [: s4 Y* C# U( V4 i+ \" o. u set roads patches with. p; @6 T8 g ~. C$ Y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, q# I: c, d/ ` (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% z" I' {8 c# I+ z' @" 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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