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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。
& D% h* {0 H% ]) K" Dnetlogo自带的social science--traffic grid这一例子当中,5 n) a7 b! h/ c
globals D- X; u4 c: S6 Y; n9 K
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3 c# V& t7 b+ S' y# V grid-x-inc ;; the amount of patches in between two roads in the x direction
- k1 d: {# \. P5 M8 F* F j. { grid-y-inc ;; the amount of patches in between two roads in the y direction; q( G5 _. Z0 P
acceleration ;; the constant that controls how much a car speeds up or slows down by if
' A6 i4 f1 D6 z/ D1 k ;; it is to accelerate or decelerate7 \" W6 Z2 s/ r) U- E
phase ;; keeps track of the phase% Z t( \: w. y% x* h
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure( I2 }0 N& z1 C2 i7 V3 h
current-light ;; the currently selected light$ |) _ {1 c! l K: G
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;; patch agentsets
& M) U+ a& w% k- ?4 n, ~ intersections ;; agentset containing the patches that are intersections1 Q7 G, T4 J9 S* |/ {' ?
roads ;; agentset containing the patches that are roads
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turtles-own8 O* A, t: [% ] z
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speed ;; the speed of the turtle8 ?2 R7 L# g% }: M% U! f, M! ~+ I7 Z6 V
up-car? ;; true if the turtle moves downwards and false if it moves to the right) v3 @) u8 j. z
wait-time ;; the amount of time since the last time a turtle has moved$ N' b k5 y, A, V- Z4 I+ Y
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: h" W1 ^. U; \3 e/ Spatches-own
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4 n- O' g& T3 v$ B intersection? ;; true if the patch is at the intersection of two roads
8 E. U7 L* ^4 g1 Z$ [: Q green-light-up? ;; true if the green light is above the intersection. otherwise, false.
. F) J) R2 t* s ;; false for a non-intersection patches.) T: T- B4 h+ b
my-row ;; the row of the intersection counting from the upper left corner of the1 G) Z$ P" K8 n5 u
;; world. -1 for non-intersection patches.3 h$ j3 R3 I5 Z; j* X
my-column ;; the column of the intersection counting from the upper left corner of the8 j0 |! B$ `2 B b
;; world. -1 for non-intersection patches.
% S' h; |+ n9 u& J3 ? I; m9 S my-phase ;; the phase for the intersection. -1 for non-intersection patches. k9 U# e5 \# \
auto? ;; whether or not this intersection will switch automatically.
9 V6 Q0 b% N; U8 b. T ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
; p1 I+ X A& [$ x7 E;; Setup Procedures ;;
/ Z! L3 Z% I" \;;;;;;;;;;;;;;;;;;;;;;
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5 C3 g& o' k2 O' D0 @- _6 M% u;; Initialize the display by giving the global and patch variables initial values.# @- x: b8 z. L6 w7 d( @
;; Create num-cars of turtles if there are enough road patches for one turtle to' z# ~: \. ^" z) @: Y" W
;; be created per road patch. Set up the plots.8 {5 s7 P$ C K7 e# V8 z; K% f' {
to setup! r q) Y8 P- b2 w2 `. m
ca
( g' ?; i% n1 O( f3 C/ u$ j setup-globals
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;; First we ask the patches to draw themselves and set up a few variables) C A/ g2 J* A; k
setup-patches# i, x% @3 [* f3 \3 @' Q
make-current one-of intersections) a, m& s$ t' f5 V) R; d
label-current' x& P, @2 U) z' H# D
( p6 b$ L# I7 i# g% Q set-default-shape turtles "car"
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% V" q7 P: s, a" j if (num-cars > count roads)
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; S @9 m: m# o7 D, D9 o user-message (word "There are too many cars for the amount of ", Y: _% [/ {: T& O) P
"road. Either increase the amount of roads "6 n6 E2 u4 S$ K y
"by increasing the GRID-SIZE-X or "# a1 }/ ]# V, x! P6 d# m* P0 `' s# H
"GRID-SIZE-Y sliders, or decrease the "! [( p; C/ _, @3 M4 `# {/ V5 ~
"number of cars by lowering the NUMBER slider.\n"
3 |- s5 N9 V' g. c) J5 d" y3 I "The setup has stopped.")( f! b$ N5 s! q0 t4 R" i2 y
stop
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$ A4 R0 Q( }5 _, e ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color. g# P: i2 `) P- \5 Z4 Z
crt num-cars _( {+ X$ ? \0 k$ l* `
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setup-cars ~' z+ L% |% w6 P7 H0 M. k# W
set-car-color/ ]+ M7 |+ K T7 o
record-data
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8 p; Q/ F7 k f& O! f ;; give the turtles an initial speed! A: m! I; b& }9 d! z
ask turtles [ set-car-speed ]
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5 b, s- A8 n2 ^* x reset-ticks* w! H2 z0 ?# K, P" d
end
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. e" v+ [2 x. z0 b2 ]) S;; Initialize the global variables to appropriate values
% ?( W- Y, _) e7 ?4 s' Hto setup-globals
: q8 Y+ n8 k8 Q$ U3 w set current-light nobody ;; just for now, since there are no lights yet* \5 y+ J( J) r% _; G1 o1 k0 H
set phase 09 Z( q) H' D" @. T" L" Y/ ` y
set num-cars-stopped 01 K' u) w1 s9 A
set grid-x-inc world-width / grid-size-x
' l f. e% ^2 B, }3 P( v# L 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 boundary1 y: j( A7 X. e% M, { B! L1 u# d
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
+ F5 H# B0 c0 T& t+ g/ T7 M! o;; and initialize the traffic lights to one setting2 E$ j2 x7 M: r1 R4 c
to setup-patches
6 {& w! k1 Q( e5 r `1 o: _ ;; initialize the patch-owned variables and color the patches to a base-color+ R1 J! Z, c$ O. c! a0 y
ask patches9 O5 A! c* n) Z$ ]* I$ ^6 _- Z; j$ \- d
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) s; Y# Y3 t9 J: y9 q set intersection? false
9 ]' w! M: y4 G set auto? false
! _8 c% ]* |/ j: `9 T3 S set green-light-up? true0 a3 k. T3 K" |& v& l
set my-row -10 `) j r) m7 E3 t
set my-column -16 [ `3 [( K2 t
set my-phase -1
3 P, G2 w/ x* F l0 e. G- [! t' @ set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
& s5 y0 t; S2 }* |* W1 D$ z' h set roads patches with
|$ u; m. M6 Z8 E# b9 U* { [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" W" [2 i7 }- Q$ r. N
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, @4 Q* z9 u, c9 Y; \) L& y set intersections roads with0 y C" {) f7 w% f: C( M% O9 Z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and6 f# r$ v% V+ r( H" t# j( e
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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! B# @- |8 }, W* F. X$ l ask roads [ set pcolor white ]
* |4 e1 \3 `" b4 ~5 P, B4 x setup-intersections
q9 N" S1 j, d2 @end% y7 F. ], w; k$ D+ ^
其中定义道路的句子,如下所示,是什么意思啊?
, Q& P* B, \ m% f3 c set roads patches with
$ w8 `- _+ ^3 T, m2 o! v& Q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 H6 o6 L- J6 K& B
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 o# h2 k$ a/ }8 [$ c2 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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