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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。( P; ?6 C2 C9 S5 Y' C! c
netlogo自带的social science--traffic grid这一例子当中,
1 P$ Z, _# s$ v( f5 v( {" Eglobals1 s/ J0 W0 ]" L$ {" l9 Q+ F; m
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" T+ [( J# }7 d4 ^: W grid-x-inc ;; the amount of patches in between two roads in the x direction# O/ m4 y$ n# N/ Q' g3 ]
grid-y-inc ;; the amount of patches in between two roads in the y direction6 x2 C6 B$ Z. P# F* [
acceleration ;; the constant that controls how much a car speeds up or slows down by if
7 Y5 {" D' O' D0 i ;; it is to accelerate or decelerate( l" d( O: e \. s8 g5 S8 n4 n
phase ;; keeps track of the phase
' J0 A0 I8 U* F8 H6 y# Y. s8 @ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure$ e. C) y* `3 t- N- A
current-light ;; the currently selected light6 ~3 [9 P, ~3 U9 y) j
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;; patch agentsets
" l; _: u% h4 x; z% {0 i intersections ;; agentset containing the patches that are intersections
' E3 c! A$ p$ _+ C) y1 z g& X roads ;; agentset containing the patches that are roads
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turtles-own7 |- ~, E( ^" [- k7 ~* j) { ^
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speed ;; the speed of the turtle. t6 k9 c9 {' h: y x) c$ g* s! a
up-car? ;; true if the turtle moves downwards and false if it moves to the right
. ~- D8 X. p, {) h wait-time ;; the amount of time since the last time a turtle has moved
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patches-own" b A3 D1 ]; w7 M
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; G" U5 Q5 s% S2 a( o intersection? ;; true if the patch is at the intersection of two roads
3 d! w8 Z, S7 T7 t0 t green-light-up? ;; true if the green light is above the intersection. otherwise, false.2 N* l z+ u8 i4 \
;; false for a non-intersection patches.
* U/ z. u- U7 M! l9 n+ l1 o my-row ;; the row of the intersection counting from the upper left corner of the
, e4 |1 x6 |1 D( v j; L' Q6 x ;; world. -1 for non-intersection patches.
+ B( G9 H/ U2 p) T5 Y' f+ X my-column ;; the column of the intersection counting from the upper left corner of the
/ m) h5 y! v' _( l ;; world. -1 for non-intersection patches.$ { v% Y4 P2 y# ~
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
, T( g: c4 n2 W$ Y auto? ;; whether or not this intersection will switch automatically.! g) ?. O5 x- Q! q& [0 B
;; false for non-intersection patches.
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7 N/ u; I% q+ \" x+ o$ @;;;;;;;;;;;;;;;;;;;;;;1 V; o6 N3 E: }2 y( v
;; Setup Procedures ;;' H8 q3 o( j1 x" O% M+ F
;;;;;;;;;;;;;;;;;;;;;;( B0 p- F3 p. g* m8 K. N
) O" N( K' ^- i- n;; Initialize the display by giving the global and patch variables initial values.% f8 b4 ^2 C: E3 ~9 D* l7 l- E
;; Create num-cars of turtles if there are enough road patches for one turtle to; |" B/ v7 q$ j3 `2 y1 `1 S5 c
;; be created per road patch. Set up the plots.
2 ] `$ h! U3 r) D; _3 xto setup5 I1 z3 ]# t$ @
ca
) }; `6 l0 u% g: T setup-globals
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. e9 \' z: E, v/ w: S8 T ;; First we ask the patches to draw themselves and set up a few variables& j6 X0 C3 t9 {! m; F# }, A& a
setup-patches, A1 m! e1 ~$ @
make-current one-of intersections; ]' Z1 u( P4 Q/ ?2 \! E
label-current
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& h p$ K) h4 R, @ set-default-shape turtles "car"% M; ]6 s" j/ K; h& k3 z
5 u T! \# `7 l! Y! x1 O! z) w if (num-cars > count roads)
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& l7 y9 r3 v p$ M( \: c user-message (word "There are too many cars for the amount of "
$ h2 \0 }( X: ]4 h "road. Either increase the amount of roads "
* ]2 G: E; P5 K9 ~) H "by increasing the GRID-SIZE-X or "
3 e% F/ q! R$ `4 e "GRID-SIZE-Y sliders, or decrease the "
6 A( _; P& J9 n4 Q4 q0 w) q6 T5 C "number of cars by lowering the NUMBER slider.\n": A3 ]2 N& R9 p4 y' @$ f! r
"The setup has stopped.")6 j3 O' U1 O- o8 Z* T9 _
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# m5 K) G; ?0 k; c; V- \- S* M( J crt num-cars( F- z- z/ y9 N" A" E
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setup-cars
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record-data
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7 d- [2 [6 B9 d/ ^: b5 T8 ` ;; give the turtles an initial speed
, S& d/ ^$ f" [* {; y, x: ? ask turtles [ set-car-speed ]: O; y$ X( B0 v$ K
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reset-ticks# a$ B, z6 `6 k% W
end
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8 f* j1 H, g! |0 ]$ s0 p4 K;; Initialize the global variables to appropriate values# _# w3 {7 L4 Q/ H9 O5 M
to setup-globals$ f8 k: r2 c% j" p; {' Q( |; U/ s3 o
set current-light nobody ;; just for now, since there are no lights yet
4 N/ b/ V4 u% U) `. O set phase 0
9 U1 f4 b) j. `2 `& S3 @3 \ set num-cars-stopped 0
. f4 V( ]& [9 a. ?' d- J set grid-x-inc world-width / grid-size-x7 x! Z Z/ p `% D
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 boundary J! {& @+ Y: a$ _! ?
set acceleration 0.0990 ^/ |4 ~) H4 V+ t1 }5 X
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
0 Y" ]! H5 E* y: ^" X$ x;; and initialize the traffic lights to one setting
K, C- U& }" v' J) f [to setup-patches
$ B6 o o {" q L9 {! P: F/ q ;; initialize the patch-owned variables and color the patches to a base-color
4 ~1 [$ X7 s- b# n$ y4 y ask patches
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set intersection? false# t0 o$ l# h4 U- t1 M9 X/ ?7 r
set auto? false& G) B g# g+ I( j5 y; J. @
set green-light-up? true j2 H" |0 a, ~" i4 K
set my-row -1
" V; X, n1 B- u4 S% {0 b M3 n/ t set my-column -1+ H# c8 M+ |# P) v; u
set my-phase -1
2 v: \0 w& H6 e set pcolor brown + 39 t* Y7 W8 z7 V, v2 c% ^
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/ E1 ~9 T6 q% p ;; initialize the global variables that hold patch agentsets
6 M- c3 C) g$ L0 u( C) n+ P" s set roads patches with/ a8 q3 [- n6 ?% t3 L7 r& O
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
. j5 ^- k) H g6 f& k5 N (floor((pycor + max-pycor) mod grid-y-inc) = 0)]. w. i4 q* j/ [) E
set intersections roads with+ s1 D, d* }. M9 W) ]/ E
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
6 ?; i# `$ a: G8 ]: J (floor((pycor + max-pycor) mod grid-y-inc) = 0)]" C3 W; X+ Z. k; l( P! y) R
0 v$ Z+ ` ~( h# n0 d ~) b9 [ ask roads [ set pcolor white ], {6 G4 L9 h. J- h) {8 e
setup-intersections" w: s% p' G! |2 J$ U g
end) G! `! F) q8 y
其中定义道路的句子,如下所示,是什么意思啊?% o+ K. G* p5 B* f7 u7 w
set roads patches with, M2 v; }9 q* A! ?( Y" y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 Y# _# O8 S) {0 |
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 J8 C2 [% x5 O' g' f$ J2 w+ ]. l
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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