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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。8 [& o. E: g0 k5 o
netlogo自带的social science--traffic grid这一例子当中,
1 L& d% D j9 Z! |globals. B( S7 H" M' P' k5 L% Z
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grid-x-inc ;; the amount of patches in between two roads in the x direction
' i8 c. B0 T: U$ u% c" u grid-y-inc ;; the amount of patches in between two roads in the y direction
$ t4 V$ h$ H% C, t' O: F) P: m8 P acceleration ;; the constant that controls how much a car speeds up or slows down by if
( E" g( A; h# r. E ;; it is to accelerate or decelerate
+ i& e% Z$ j" J, M: B phase ;; keeps track of the phase, j7 l7 O$ O" E; v
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
: q7 t a2 D9 E( P# H6 k# l current-light ;; the currently selected light E1 S6 y$ M4 [, N5 T* a
; J+ @( h. D% Y! g7 D" u3 O ;; patch agentsets; C1 Y5 |1 H# [
intersections ;; agentset containing the patches that are intersections v. {" }" s6 L/ @5 S/ s9 T
roads ;; agentset containing the patches that are roads/ y. Z8 Q* u, _1 A" i
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turtles-own, ? {; W1 l6 v# v
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speed ;; the speed of the turtle5 L7 x8 G1 B( _) ^
up-car? ;; true if the turtle moves downwards and false if it moves to the right3 e- X' P: C% D% I" N# h* I n
wait-time ;; the amount of time since the last time a turtle has moved
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" `$ I( Z! ]: W$ t3 T4 t, e+ npatches-own
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intersection? ;; true if the patch is at the intersection of two roads
7 f/ `( V& Z: t7 d8 P6 _3 N) k green-light-up? ;; true if the green light is above the intersection. otherwise, false.
A _1 j" @; `' F$ ^# h ;; false for a non-intersection patches.
v4 h' f5 @. [) r K0 N4 {: i my-row ;; the row of the intersection counting from the upper left corner of the
5 i6 K' n0 C( B0 t8 h7 a, Z$ [$ H ;; world. -1 for non-intersection patches.' O% s$ t; f% L/ K4 J
my-column ;; the column of the intersection counting from the upper left corner of the
" R9 t- b' H, }4 K ;; world. -1 for non-intersection patches.
& P, a9 H1 A/ l4 r7 J9 ]! w my-phase ;; the phase for the intersection. -1 for non-intersection patches.9 {: l) ^& ~& b
auto? ;; whether or not this intersection will switch automatically.
3 P( P( P4 o* Q) x4 y* C0 N ;; false for non-intersection patches.. C. y$ w2 q1 T5 I/ O B9 K* [. C
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;;;;;;;;;;;;;;;;;;;;;;0 j" l7 w Z9 R, T6 R
;; Setup Procedures ;;
$ o" w6 k# R6 e( z;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
1 h/ ?+ t1 Y) ?/ K' a7 };; Create num-cars of turtles if there are enough road patches for one turtle to
- V% s! U @3 g. A" {9 R3 k$ M3 }+ p;; be created per road patch. Set up the plots.7 i6 `: o1 K/ f$ V4 [& Q
to setup, E/ W7 r/ Q6 N" Z7 h
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
3 a% D" D* ^5 m6 Y t1 q setup-patches
& x1 Z4 z L O$ k: e q make-current one-of intersections' l0 R5 U$ b. L3 R4 e5 R
label-current
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set-default-shape turtles "car"& s" p7 i3 U5 w: s2 ]( q t
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if (num-cars > count roads): H' Y. p# Y: o# c) x; X' O) ?
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1 f9 E% C% V; i: l3 k user-message (word "There are too many cars for the amount of "1 I+ J5 ]% S2 N9 s' C$ P' `
"road. Either increase the amount of roads "
# T" W4 V$ `7 f$ a "by increasing the GRID-SIZE-X or "
: f- H% g7 e0 h5 k; X "GRID-SIZE-Y sliders, or decrease the "
' }, ^% \$ Z: L "number of cars by lowering the NUMBER slider.\n"8 }3 h0 y, h' f* P U( g7 q4 r! M* T7 s
"The setup has stopped.")! I( S+ ^ `; ?. A
stop
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5 H" @5 M: A2 s" }; r ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color6 ^7 H4 m9 y: t' b6 v3 W
crt num-cars
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setup-cars' u O, E$ B5 e0 c) T" C5 M0 H2 T6 C
set-car-color1 g* O0 B) U% |
record-data. z! K* y! x# G0 b, z+ t
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- z+ B: b2 l$ J" X ;; give the turtles an initial speed0 r) `. s" C0 V3 r$ W4 R* s) b
ask turtles [ set-car-speed ]
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1 h: p. I! j# a% a/ I, h reset-ticks
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; y8 i5 I' R( {$ Q+ m;; Initialize the global variables to appropriate values
/ T7 x9 s+ D+ G% S1 Uto setup-globals
3 r- R/ i; Z+ v set current-light nobody ;; just for now, since there are no lights yet
/ e2 | U1 g: z" X set phase 0$ K8 b: V" C& H) ~
set num-cars-stopped 0
6 N6 Z# h( u! B+ |- k set grid-x-inc world-width / grid-size-x
* E/ E {8 h8 V+ }9 O6 R) F set grid-y-inc world-height / grid-size-y( j6 L; n6 `" X) b3 u
: M: l8 q5 J" g/ f/ k; ] ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary6 C( k% N# T6 E8 O! }6 i! @% x% q
set acceleration 0.0997 B5 i9 A! D, E4 c
end# k- n4 z" l) [0 K/ D2 g
/ z2 U" L& n# J3 c, F2 w4 v% V) [;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
8 h( U2 U" r- o6 ]- ]2 `9 v;; and initialize the traffic lights to one setting
! ~7 I4 w5 E$ Y2 a3 h6 Y9 ~ |to setup-patches
2 U0 o1 f" D7 x. D ;; initialize the patch-owned variables and color the patches to a base-color
* R2 N3 l" q7 W0 j0 m+ s ask patches
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set intersection? false# R3 e8 _" T6 d& U6 y
set auto? false5 ?' B0 _6 m9 P9 s+ b
set green-light-up? true
* Q$ k+ y" }/ _8 w set my-row -1
: N1 R- x! W/ Z/ Y set my-column -1% f* ^2 G1 z, m! I$ _" g" d( m' V9 M& ?
set my-phase -1
& c* J. n+ O; f5 h set pcolor brown + 3# o$ e/ b) @0 ^
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: x* g! y2 i! m1 q ;; initialize the global variables that hold patch agentsets
, K9 u* f+ e: ~5 e- ? set roads patches with
0 @- W3 j( u, ^' @ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 C$ c7 E& R! r$ p5 e d8 ]' p
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], A1 F3 F3 ?: g
set intersections roads with
* K# a" b5 \) y; Z9 { [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
, \4 Z& n% s; O! P1 V5 q$ l! V (floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 d5 G: |* p0 Y5 S0 q* N
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ask roads [ set pcolor white ]+ X; z; V6 w3 X' |" M# `* b$ e
setup-intersections* P! i* Q: C6 S# X' w
end9 t6 ?0 U: A, [+ ~ u2 Z
其中定义道路的句子,如下所示,是什么意思啊?1 e I& I7 r! c: r# R- k" b
set roads patches with
1 ]! C- U0 t% I) `0 }. j1 y# q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, ]7 G, ]3 t6 C) m& d% J
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 m7 P% c5 @2 p* a$ x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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