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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。& |; q8 Q' _, K
netlogo自带的social science--traffic grid这一例子当中,; R& ?. G2 e5 r+ }0 c
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' n7 H& ~1 ]5 e: H. l1 W$ } grid-x-inc ;; the amount of patches in between two roads in the x direction y% T: @5 F7 r3 [1 u, M
grid-y-inc ;; the amount of patches in between two roads in the y direction
3 e" l: `8 o* ^: {0 R acceleration ;; the constant that controls how much a car speeds up or slows down by if
% i; C! r/ d% F9 L. q ;; it is to accelerate or decelerate" S7 t, w' Z" A. F& X$ R/ D) y
phase ;; keeps track of the phase9 @5 g; B1 p) ^3 n% S- z6 G% E
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
* t: ]0 ^1 Y- l* ?8 a, {- ^' l/ B current-light ;; the currently selected light% z) E" r" Y: u" @! d
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;; patch agentsets3 r0 v+ @. B( n- y/ ]3 h
intersections ;; agentset containing the patches that are intersections
. B' V* [3 c' D7 A& |8 n9 J6 k roads ;; agentset containing the patches that are roads
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& t6 {" O( n0 r5 B& Hturtles-own9 k9 M# ]: F; D& x; ?
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( Z; o+ a/ S" y( G* D speed ;; the speed of the turtle
7 q; L5 {6 N, c7 z" M$ O up-car? ;; true if the turtle moves downwards and false if it moves to the right
- Y Q& o7 B2 _( W! Y$ H3 p3 E wait-time ;; the amount of time since the last time a turtle has moved
8 h8 O6 X* E3 m2 v' Y" I8 V6 o]; |* p( a1 z) ]6 ^. n5 y
6 v' N4 x' k, x+ v R4 g2 n. Zpatches-own$ f+ w' _+ ^6 X
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intersection? ;; true if the patch is at the intersection of two roads* d4 A8 {5 \- W" [
green-light-up? ;; true if the green light is above the intersection. otherwise, false.( T% k4 r; |8 W- ]0 p
;; false for a non-intersection patches.& f+ G( m# }; L, J: {) P
my-row ;; the row of the intersection counting from the upper left corner of the
$ g' {$ B, t7 o, H, l ;; world. -1 for non-intersection patches.6 X* t0 ], T N4 ?" b) ]
my-column ;; the column of the intersection counting from the upper left corner of the
! k9 F1 g& P4 z8 c% c& q ;; world. -1 for non-intersection patches.
2 o0 J! z9 K2 K# Q7 P: d my-phase ;; the phase for the intersection. -1 for non-intersection patches.
4 U' k; }3 P% n' q) [" y6 a2 y auto? ;; whether or not this intersection will switch automatically.
/ U; u5 Y1 S7 W9 A$ d ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
4 x1 i! _: }, ~;; Setup Procedures ;;* {. o8 D' k. H& J5 O% L8 B
;;;;;;;;;;;;;;;;;;;;;;
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: D$ v7 T0 x) }8 x;; Initialize the display by giving the global and patch variables initial values.
" Q/ z. G9 W$ I+ ]1 ^; |;; Create num-cars of turtles if there are enough road patches for one turtle to
. o* |" ? X+ ]/ S- s;; be created per road patch. Set up the plots.0 `+ {8 a9 E. H+ r& D$ c3 ?0 _
to setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables" u0 \2 E" v& \' }6 P
setup-patches: p, M. G+ ]9 H1 k4 {: Y" X
make-current one-of intersections
+ [) E$ A; P% K1 W3 \# f5 L label-current
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% [* Q) A+ t0 p" o( ?$ b set-default-shape turtles "car"* Z! G0 h& B! j! G3 f$ p
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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 "
3 l5 L$ {7 g+ ~' s. F. z7 D% b "road. Either increase the amount of roads "
% C/ Z9 ]1 {' b% a "by increasing the GRID-SIZE-X or "+ N# P! |* v( k* r& M9 j
"GRID-SIZE-Y sliders, or decrease the "- e$ Z* C# o3 k
"number of cars by lowering the NUMBER slider.\n"3 a% p2 d; P& m6 A# m$ ^* U `6 H
"The setup has stopped."): y5 Q2 W" r* b
stop: _8 b) Q5 |. O& x: g+ Y2 V6 c
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
0 r$ \8 o; S% [ crt num-cars
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setup-cars
+ t+ y1 K: q T5 y7 t+ q! M set-car-color
9 ]5 ^7 C6 ^8 k/ } record-data6 @. l5 V; t8 j. g
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+ ?6 `; x% b) ~$ F+ f) G ;; give the turtles an initial speed
6 ?& Y% _9 L @' C$ M D( z ask turtles [ set-car-speed ]; s- k0 ?) T; U" S& w* X3 @
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reset-ticks8 k6 t) z! \1 e: X) B, H
end
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;; Initialize the global variables to appropriate values3 ~& d( T0 E3 \5 b! u$ s+ I$ J( j( W
to setup-globals
# P8 Z. z C9 L# C! x! @ set current-light nobody ;; just for now, since there are no lights yet' o8 E" z" R" q) _9 N) U4 Q- \$ _6 y: x
set phase 0
/ F) N% M% j) a L set num-cars-stopped 0
8 k. B, z+ U5 U. n. Y% R set grid-x-inc world-width / grid-size-x
r0 w% e3 [2 |% m ~0 b 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: j- ~# Y/ [% t: E |
set acceleration 0.099
$ o( g0 E+ V6 Pend
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* \! y. J O; D;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 d+ B" w @4 D- U1 F( ^
;; and initialize the traffic lights to one setting" V- P9 Y r8 T+ {
to setup-patches5 ~1 j# o, c& z" u8 B* `8 _
;; initialize the patch-owned variables and color the patches to a base-color6 Q+ x3 l6 k% g) P0 I
ask patches
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4 C" Q+ e1 D7 c' ~. H9 Q7 h2 }- ~ set intersection? false3 b/ t: F0 ?7 c6 I6 Q
set auto? false$ Z: {9 N* v) A& N
set green-light-up? true: F A7 R$ T) P4 b1 x' C
set my-row -1
" ]4 y2 ^9 S: u6 b, s0 j set my-column -1
: B) E( j; c; G; A2 g set my-phase -1 I+ ^# D$ c5 W# R6 x3 ^
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
1 j8 m+ {0 E$ f/ U0 j0 _7 B& I set roads patches with9 T: l0 y8 t! P1 {) v( G1 ^
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 Z# Q5 R" K$ V* n# O (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
r% {! I# ^2 j* Y: ?: ? set intersections roads with- O6 j6 s. H( ?
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and: r% P0 R/ r5 n5 {# _1 g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]" E& \. Y( D4 a% E. G6 f( D% I4 K
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?) N7 P2 V: V. W R
set roads patches with
9 \9 d7 J5 B. c8 K% g, S [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or7 X6 p$ s: E/ E6 \) i' v) G
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* P: @! O% h4 `) z6 k8 @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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