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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。" a+ e( T# Y9 v& _: t$ O
netlogo自带的social science--traffic grid这一例子当中, j) ?/ V5 S7 _$ |
globals1 j0 h$ x5 s7 R* S) P
[
& G# f- i2 R) L: I3 G grid-x-inc ;; the amount of patches in between two roads in the x direction
4 _, B1 c/ e( b' S( S0 Y5 { grid-y-inc ;; the amount of patches in between two roads in the y direction
. ~8 \6 O( Q7 B9 z2 d8 I& k- | acceleration ;; the constant that controls how much a car speeds up or slows down by if
$ {. K( A0 q3 r Q5 M ;; it is to accelerate or decelerate
9 i: Z& r1 _- e7 \5 W; \9 w phase ;; keeps track of the phase. M. `4 ?7 {0 s& v6 M" b; p0 L
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure2 \$ L0 m" w% l
current-light ;; the currently selected light
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& U+ y3 F |/ ~6 S/ X- w. n4 |; i ;; patch agentsets
' X% j! b1 f% [* l! k/ R- X& { intersections ;; agentset containing the patches that are intersections
( N7 j9 }3 y/ q6 a% h7 }6 o roads ;; agentset containing the patches that are roads. o- }/ U# n Z5 ^5 x" _$ L9 y9 L
]( ]4 C0 g5 Q# |4 e n7 |% d
/ @- i$ Y* M3 J6 Fturtles-own
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speed ;; the speed of the turtle
|, C* \" U9 F0 \6 o* ]0 n- M up-car? ;; true if the turtle moves downwards and false if it moves to the right
g: w8 ]4 |9 _7 o! s* f4 C wait-time ;; the amount of time since the last time a turtle has moved
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+ x6 m; g$ g: h% w& rpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
/ q8 p3 B* z4 p1 |8 L1 M green-light-up? ;; true if the green light is above the intersection. otherwise, false.5 U/ g( R' e" T( [8 ^, ^1 e
;; false for a non-intersection patches./ z# h; C- O& R, L' S; l2 F: t
my-row ;; the row of the intersection counting from the upper left corner of the E7 ?" `, Q$ J) X
;; world. -1 for non-intersection patches.
7 J3 ?% s& @4 u2 W' [+ K m my-column ;; the column of the intersection counting from the upper left corner of the
0 Q7 ~3 R: n( R" E3 P ;; world. -1 for non-intersection patches.3 n4 B6 _4 B5 P
my-phase ;; the phase for the intersection. -1 for non-intersection patches.* H. W: m4 Z" g% X) F0 p0 K8 Q
auto? ;; whether or not this intersection will switch automatically.
+ V" g! H( y2 k7 _8 d8 {- g b ;; false for non-intersection patches.7 ]! Q$ x/ r$ \. q8 ^! G
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;;;;;;;;;;;;;;;;;;;;;;3 |- a! ~4 w& `9 @
;; Setup Procedures ;;
2 N. v$ `$ v4 z% M* Z;;;;;;;;;;;;;;;;;;;;;;& _( R- Q' l* {8 _5 q6 R7 t8 f
, H# f/ Z8 M* U3 ]0 R;; Initialize the display by giving the global and patch variables initial values.
( O- _( I- f* O* g4 o1 L. V: d' z9 ?;; Create num-cars of turtles if there are enough road patches for one turtle to9 d! t( I* b# }. t8 M- z' g6 M3 r# w
;; be created per road patch. Set up the plots.4 z% t- R$ j: ?" a. k
to setup" {% E" H7 M+ F* [( X+ P# J0 q+ L
ca
3 W" ~! a- B. X% e* ^7 e0 } setup-globals
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. `- Q' d' a* c* f8 U @% c4 Y: d ;; First we ask the patches to draw themselves and set up a few variables
3 H4 O0 T/ i/ w! h: r. ]+ _, p5 w/ x setup-patches
% A" T/ I; u$ P" {' F& ^ make-current one-of intersections
: l0 j Q# Z6 I label-current8 k8 k- I* j' ?9 ]$ D/ y
6 b/ c8 Z2 U: i, m' T set-default-shape turtles "car"
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if (num-cars > count roads)8 ?/ c8 n9 e; j0 z8 j1 L) [
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user-message (word "There are too many cars for the amount of "7 k* M+ ` }9 I0 ?# E2 C
"road. Either increase the amount of roads "6 s8 k0 P, m2 {- ]8 B8 Q! s
"by increasing the GRID-SIZE-X or "
# q6 U7 i+ A3 }& ^( d* k& z+ i6 ] "GRID-SIZE-Y sliders, or decrease the ": V* r/ `% K, W2 G8 P% U
"number of cars by lowering the NUMBER slider.\n"& X5 M5 i! c6 r# K* \
"The setup has stopped.")- A% m4 ]3 s! ~- b; ^
stop! u2 X8 }+ M' Z1 ~
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! t' {+ [( q+ B/ c0 n ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color. w5 Q8 {; l6 \3 x9 K5 k
crt num-cars8 f# T; C! f* ^. h$ A
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setup-cars* d/ O1 {! R4 h# Q/ i% @5 u
set-car-color
0 K6 |- {! t2 |. N( J y3 b record-data
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% I# q, H- Z! }1 I! Z& f7 o ;; give the turtles an initial speed u& r, j" f& `! Q; \7 a
ask turtles [ set-car-speed ]
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reset-ticks& T" [+ k3 u+ K# r% z: T' a+ A
end
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+ P4 C6 @' I2 };; Initialize the global variables to appropriate values$ q7 ^: B& ]# L
to setup-globals
0 d# v: b- P& A$ e( O, r- r% Z set current-light nobody ;; just for now, since there are no lights yet% t& j9 e/ _; W5 _0 G% L0 i$ {0 I, N
set phase 05 ?% U% P- C1 M7 ^
set num-cars-stopped 0
) ]+ K& F1 m0 X2 E. e) j+ u set grid-x-inc world-width / grid-size-x
& f4 U7 }- M2 m g" o6 G+ g set grid-y-inc world-height / grid-size-y, T0 Y# N* w i' }+ Y0 S
1 e4 G6 Y2 U+ C% H0 ` ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary; `0 ~; A0 a( C2 K9 i
set acceleration 0.099 ?4 o w) g2 H0 J) T: P
end$ n l. N9 \1 L0 k, { T
8 \, F4 ^, v$ g8 X;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
4 h( M) p9 f _$ O;; and initialize the traffic lights to one setting
! Q; h# `1 J2 F% P5 h' K) H/ A$ I+ yto setup-patches: p* e) f% Z/ P! w1 j
;; initialize the patch-owned variables and color the patches to a base-color2 w: G; m5 x) p% K' L3 C7 a B5 [
ask patches7 L, w* T2 H" R6 D# B% M
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set intersection? false# e7 h7 v! i; v( P, V" O" ]
set auto? false2 _- R; I$ l ^# N
set green-light-up? true
4 }/ g3 M1 s: e' O; y. p" {. T7 N set my-row -1
+ T; K w6 A# [' J( {* m/ R2 U set my-column -16 ?2 K, _2 v; b- Z2 C
set my-phase -1
3 [5 F% O, r8 d3 \6 h8 I3 t! u" v set pcolor brown + 3 I. S% y0 U, K. b4 U
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% |+ ], F3 \) x ;; initialize the global variables that hold patch agentsets2 E2 L8 S" S5 \
set roads patches with
5 t3 S1 [0 l8 p# G4 w# T1 } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 O' R) ~0 J4 y# \4 x: S/ d
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]' O" i9 M5 }- P1 E
set intersections roads with
" @: f/ S. G7 s% n( @ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
2 P3 w+ Q# ?. K4 p; B (floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 y. }/ H& s6 g7 W
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ask roads [ set pcolor white ]( a2 T# V" f+ s7 r0 t6 O/ D
setup-intersections8 P- e0 U' S) F9 |$ a- `4 d
end" ~( T. {/ j I1 w8 h+ l. _
其中定义道路的句子,如下所示,是什么意思啊?; j( _1 z2 y+ D
set roads patches with' X" n# d# ?; f o6 c! B0 E
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
4 S$ f3 d! f$ D; j' L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 M3 u6 o) ~: H# L' e7 l% W/ ^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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