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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。
3 V5 n; A" m6 d% anetlogo自带的social science--traffic grid这一例子当中,
6 D3 {5 l& e) G$ {globals% a# I# o7 ^+ x. _4 H6 i, O
[
0 Z- O6 R7 `: Y1 T grid-x-inc ;; the amount of patches in between two roads in the x direction
1 v; a9 b/ s% }3 @- A# g( S/ t grid-y-inc ;; the amount of patches in between two roads in the y direction2 N. t/ U- J# b+ |
acceleration ;; the constant that controls how much a car speeds up or slows down by if
5 Q7 V3 |; X" S* r! m ;; it is to accelerate or decelerate
; G# A& t; d4 ~3 R phase ;; keeps track of the phase
0 S7 r7 Q+ \" A; |4 w* n; \ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure6 [% H, x) A% d
current-light ;; the currently selected light
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;; patch agentsets
6 h# ]6 X0 n+ L. o+ `4 K intersections ;; agentset containing the patches that are intersections0 k$ B8 S) _8 P
roads ;; agentset containing the patches that are roads
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3 @( V0 W' }7 l5 d, f5 @' P& m9 Kturtles-own
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- Q4 O4 @$ p5 _$ T ? speed ;; the speed of the turtle
% |% g) b: g0 y up-car? ;; true if the turtle moves downwards and false if it moves to the right* R9 `' r/ H. ^; I" Y6 A( X5 n
wait-time ;; the amount of time since the last time a turtle has moved
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# Z% t- B4 N+ tpatches-own
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- C0 v+ Y0 l; o, o, A4 _1 u intersection? ;; true if the patch is at the intersection of two roads( s$ a% D/ p2 F& ^ J" u
green-light-up? ;; true if the green light is above the intersection. otherwise, false.1 d9 R" H3 ^) O6 x5 }6 a# \( a& k
;; false for a non-intersection patches.
# b1 H* u0 K7 n. d my-row ;; the row of the intersection counting from the upper left corner of the5 }5 z% ~, Q. d( y: _) ^
;; world. -1 for non-intersection patches.
/ y0 _. z- y P6 K2 }/ Y my-column ;; the column of the intersection counting from the upper left corner of the, a0 Z/ T8 A7 `! j
;; world. -1 for non-intersection patches.
( m6 r+ q- I9 V; _+ L5 V my-phase ;; the phase for the intersection. -1 for non-intersection patches.4 J/ _4 V' Q1 i$ _& T, M9 {3 D) i W
auto? ;; whether or not this intersection will switch automatically.& B u I) e$ F$ L* d5 s4 @, c
;; false for non-intersection patches.( D/ w" O: |2 S# }. e
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: b9 A4 p3 o5 z8 E h;;;;;;;;;;;;;;;;;;;;;;
9 b* w! L1 v7 t Q+ @) r;; Setup Procedures ;;# Q5 x: m d( V
;;;;;;;;;;;;;;;;;;;;;;1 g! m- ^4 D9 |2 f/ p: w
/ ` V+ W! V ` a8 W& I;; Initialize the display by giving the global and patch variables initial values.% y2 f9 l3 w0 J' D# S3 H# _0 _6 l4 p
;; Create num-cars of turtles if there are enough road patches for one turtle to
. G4 `# P, H2 L- Q4 ?. Q;; be created per road patch. Set up the plots.* w6 R0 `- s. e3 q
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
1 m3 M) ]" N# h! V" \2 X setup-patches
: C! ^* t! }* ^1 g( d3 f make-current one-of intersections
. L+ t; s6 Q) v# J9 W4 G6 u% Z label-current
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! I$ m8 A2 M8 z set-default-shape turtles "car"9 J4 W( c0 h3 P8 G- a8 ^! k* \( g- u
4 N% r9 I/ a" `6 ~3 ]2 J0 ~2 E if (num-cars > count roads)4 a9 l/ v( ]3 q: E, l2 e) @
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user-message (word "There are too many cars for the amount of "1 S( @2 u7 [$ m- F
"road. Either increase the amount of roads "
! v* {" E# ~$ f# r) Z- _+ d* { "by increasing the GRID-SIZE-X or "7 W* B) v5 m7 h# n# d
"GRID-SIZE-Y sliders, or decrease the "! X! Z6 K) n, X9 F: D' |
"number of cars by lowering the NUMBER slider.\n"2 Y( h/ d, e, g
"The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color! k: Z( R7 S' u5 z$ w4 X
crt num-cars
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setup-cars
% t6 w* A/ |6 U; X$ R set-car-color
1 E; H" ^. ?4 K& L; L record-data- |% P" S; {/ ]" F
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7 z F; p/ Q$ a5 H; R7 ] ;; give the turtles an initial speed
2 f, K3 P8 d, f) Q9 T7 Q8 n ask turtles [ set-car-speed ]
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- w" w$ ]2 a7 r# I" `$ K1 I. s+ e reset-ticks
+ O" I* Z* {; W2 Dend
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5 I7 G0 d6 f% Y! X;; Initialize the global variables to appropriate values
' O& N" _; p6 E v" jto setup-globals
5 N( h3 Q7 E+ g- X5 B1 n set current-light nobody ;; just for now, since there are no lights yet
( Y i) A: E5 x% q( N4 Q! u set phase 0* j$ a' W5 ?- N- g2 a
set num-cars-stopped 0
# `5 _6 j* A ^) A5 i set grid-x-inc world-width / grid-size-x
7 _( T" `, b3 i6 Y/ F set grid-y-inc world-height / grid-size-y" f# I) q% ?7 ^9 ?! _5 t
2 y/ H+ n6 O' i7 Z! C ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary% }" ^1 ~3 L, Z! f
set acceleration 0.099& s4 E8 S' A0 P9 U$ s4 Q
end$ B* [% v, j8 @8 E; E0 T( N
0 r, f5 |( h/ L;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
9 |' Z/ @1 N6 Q* @# X5 v;; and initialize the traffic lights to one setting
+ h! v- o& r5 C3 J H9 Nto setup-patches
8 C: d( F) u0 h9 [8 D ;; initialize the patch-owned variables and color the patches to a base-color
0 G7 Q/ O9 E# J" G ask patches
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& w2 |6 w# a" ^! H8 F0 @ set intersection? false9 B8 y& R, O7 B
set auto? false
- y4 ?0 x9 s* A* P8 I* U- p2 S& M4 K6 w8 ^ set green-light-up? true1 ?! g. s3 v% ?' g
set my-row -15 C, l6 o8 n6 M6 U2 W5 I
set my-column -1
d# A# j! d9 r4 d9 x% u set my-phase -17 Z, H4 K: Z3 `9 \5 U! @
set pcolor brown + 3
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6 D" C3 O6 R0 U, z( g) x2 F. s ;; initialize the global variables that hold patch agentsets
% y( k- G0 }) C3 t4 S# Z set roads patches with$ u5 b" o3 Y6 H' G/ ~' }! V/ l
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' F4 w" N j H7 Q3 ] (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 W) e2 A6 p1 o9 Q; u0 w set intersections roads with1 [& v1 s: C6 o. [/ F2 s5 c* a& |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
, f/ Y# O' ~2 U5 F (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]% ~# x2 K# L, h& B) r o
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?2 w! _; M# d' q1 ~; K
set roads patches with
6 ?7 N# X/ E( t: g [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 c9 ^0 M8 Y- l+ B9 ^. W6 H: x8 P (floor((pycor + max-pycor) mod grid-y-inc) = 0)]" ^5 B) y* _% a! M+ _; D
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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