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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。( I7 k" C0 M6 O3 g, |5 W2 j+ p- H
netlogo自带的social science--traffic grid这一例子当中,
" [+ v7 O/ C9 q0 lglobals2 y) S" j' `" U" e1 i
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5 ?% G! ^" c% Y. [9 i grid-x-inc ;; the amount of patches in between two roads in the x direction) F( f! J- x+ B" T
grid-y-inc ;; the amount of patches in between two roads in the y direction( |/ s5 p" u; v' W# T
acceleration ;; the constant that controls how much a car speeds up or slows down by if/ ^' `% s5 S: |4 k/ E$ W& ^
;; it is to accelerate or decelerate% g! f! Q# Q" t( Q
phase ;; keeps track of the phase$ w1 [! F/ P# O) Y& B* Y8 t* d8 n; b
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure4 m/ v- x5 H7 o" c
current-light ;; the currently selected light
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! w2 q( G) [* M/ @) p; c- S ;; patch agentsets
. b7 a/ ^# A3 W. o9 ~% D intersections ;; agentset containing the patches that are intersections
Y/ P( b2 }" C- r& i roads ;; agentset containing the patches that are roads* w. u2 k% M) H# B! j
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turtles-own z2 m- v0 S4 X' b5 [& i4 X& G' r
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speed ;; the speed of the turtle
, n' j {% e3 A1 X* G up-car? ;; true if the turtle moves downwards and false if it moves to the right! W, Q0 t" |* k$ U9 w0 A& H
wait-time ;; the amount of time since the last time a turtle has moved8 i# q6 s. \2 E. F1 F
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9 n \4 x1 u* R1 U4 Zpatches-own
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3 W: H! f b! Q" `" H, ]) c intersection? ;; true if the patch is at the intersection of two roads3 K/ Y7 e( r$ C5 ]) w
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
, m' D8 S! d v* w: d7 s* y1 D: t ;; false for a non-intersection patches.1 \* |% S0 M) a8 d8 R
my-row ;; the row of the intersection counting from the upper left corner of the8 O3 g. i+ N4 A1 n! V
;; world. -1 for non-intersection patches.8 Z# ^7 ]+ I K) j1 Q" J
my-column ;; the column of the intersection counting from the upper left corner of the
( o. d/ t- ~3 {* G) i$ G: N ;; world. -1 for non-intersection patches.
; \+ E0 p' l& x3 q7 F my-phase ;; the phase for the intersection. -1 for non-intersection patches.# N8 h3 M# C# c) X6 s, P
auto? ;; whether or not this intersection will switch automatically.8 `0 }0 [- p, o4 d! y9 n& R5 |
;; false for non-intersection patches.6 N8 g2 M4 j8 @& `( `, t
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& w$ i! Z, v. |;;;;;;;;;;;;;;;;;;;;;;& X9 E0 [, }+ M0 z* D2 u
;; Setup Procedures ;;* s! V/ w8 L9 A
;;;;;;;;;;;;;;;;;;;;;;
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1 b( _- j1 E- l! H, W;; Initialize the display by giving the global and patch variables initial values.0 m' s6 j$ y& K0 G6 \) v! {
;; Create num-cars of turtles if there are enough road patches for one turtle to
2 A2 v5 Y0 G3 e; f2 h;; be created per road patch. Set up the plots.' p& ?; N+ f1 [4 l e# N, s
to setup( N+ I$ r3 m. v' d
ca
7 b, Z, `4 f* V @4 A; i. J8 @ setup-globals6 ?, d- Y! d8 o3 w, p6 V8 u
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;; First we ask the patches to draw themselves and set up a few variables, x1 s4 n, f# g8 _8 I
setup-patches3 b3 {& T4 B# P2 [
make-current one-of intersections9 v1 G# |! \: L6 Z% n# ]
label-current! ]2 @6 k: v) j/ T6 E! f! B! y
/ ]. }) n; L; m1 d set-default-shape turtles "car"( I! `: O+ S4 }" n {4 r. Y3 q0 Q
o6 g6 \8 \! y4 C( J3 P4 a/ } if (num-cars > count roads). T& F1 v9 w; v3 @6 ]* s, `) u. T9 s
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user-message (word "There are too many cars for the amount of "
3 N( T1 A( m/ l- C' o( L "road. Either increase the amount of roads "; Q/ f5 I) M" \4 a7 D" N
"by increasing the GRID-SIZE-X or "% u6 V, h- W8 [3 x! k0 i$ S
"GRID-SIZE-Y sliders, or decrease the "* I1 T- K4 ^$ N0 G. `" d
"number of cars by lowering the NUMBER slider.\n"
' E- M, S3 Q9 f2 _7 Z "The setup has stopped.") N; O/ t0 c0 `% @
stop4 Q; M5 x3 B( `4 z7 |
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color- v- @, ]4 B9 P8 F5 J+ S8 v
crt num-cars9 k7 w0 ~2 c1 |
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setup-cars
5 L, L5 ~" Q% R" |, `" v4 `0 ?! D set-car-color
+ q0 e$ F) I0 n d% Y5 U record-data$ o9 b* Q. u3 u- n9 E f( a: w
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' P+ s" u5 H" F2 \ ;; give the turtles an initial speed, [4 A) M) \2 S3 z1 P9 J% x$ k
ask turtles [ set-car-speed ]
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$ G: K2 v# K; x reset-ticks# D( f3 i. ~8 _
end
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;; Initialize the global variables to appropriate values
4 l) G$ b7 m* y, f2 [to setup-globals: ]& P9 P7 z. P [: C& p
set current-light nobody ;; just for now, since there are no lights yet% p0 V7 K3 m3 x6 x' Z' ~+ o- y2 J
set phase 0# F* `& }7 {, p& o0 j
set num-cars-stopped 0
9 C: W1 P( M$ p: e! I set grid-x-inc world-width / grid-size-x# Z* A! X% f1 |9 {: z
set grid-y-inc world-height / grid-size-y$ J7 P5 `/ \7 g! s% q% ? ]
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary; U; U2 g3 f" j2 @2 k+ w; l. H; y
set acceleration 0.099
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6 }. X g ~/ E$ `;; Make the patches have appropriate colors, set up the roads and intersections agentsets,( W' L9 m- @3 r) r% E o: Y; _/ ]3 B
;; and initialize the traffic lights to one setting! h z7 F0 ^ c6 r4 G' H/ o) \, U* @
to setup-patches5 s+ b% g6 w2 E. l A% |9 r0 a+ ^# Y
;; initialize the patch-owned variables and color the patches to a base-color
, _4 Z1 i' Q# t# E- F. i ask patches6 N# ]) N+ M) [ S5 L7 J
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set intersection? false
; C3 ?0 o+ H! j9 _3 D) }, r set auto? false
v& C" D$ ?- z" _0 T set green-light-up? true& R" @1 P6 r/ f4 q
set my-row -1
$ L) H r; S( S# @ set my-column -1
$ b4 Z' Z" r; o+ x4 t7 p set my-phase -1, q/ z, V; \2 w9 h2 O
set pcolor brown + 3- k5 r2 o I7 q: U0 e5 S5 W
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;; initialize the global variables that hold patch agentsets
8 A! ]* |3 l7 z! c+ d. P: } set roads patches with
Y i( o( e6 M1 x4 C$ P5 o5 ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) o: o! Q" W9 Z; a$ }5 t (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( }) k% Z- |$ j; b9 r5 C
set intersections roads with
7 z/ L6 K. @3 h3 r" l9 F [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and& y' O1 i+ P D1 n8 j
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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1 _% x7 n m' t1 @0 S* G1 fend
8 R( m* f% w) A8 B' b# E其中定义道路的句子,如下所示,是什么意思啊?
) @, u, c- g$ y1 c p set roads patches with
& c3 u9 Z9 i) Y/ o4 | ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ o3 b- _9 a0 p# j, J, u' E7 m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; g- i2 C4 U9 s$ f; `! D; J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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