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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。5 Z9 F% T. z8 z5 b# M
netlogo自带的social science--traffic grid这一例子当中,3 X9 `! F6 V- i5 B) H+ x
globals$ Q6 U$ t* h6 H w R- F
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grid-x-inc ;; the amount of patches in between two roads in the x direction
1 |% B+ k6 m5 X6 g6 l% C4 P$ s grid-y-inc ;; the amount of patches in between two roads in the y direction
" Z2 S# \: w) ]. }8 n5 ^2 t' j: F1 m acceleration ;; the constant that controls how much a car speeds up or slows down by if
- I v3 e3 ]( V, y7 A( a ;; it is to accelerate or decelerate
* T4 v# W: k7 r5 e3 U1 I phase ;; keeps track of the phase. f5 N+ o4 I) l* ^' W
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
$ z- i O$ H" b' @! a4 N current-light ;; the currently selected light
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1 v5 g( v1 L1 f" ~ ;; patch agentsets% j! g7 d ?2 t: T6 H; c
intersections ;; agentset containing the patches that are intersections
/ [$ A, K7 z' c: p9 S roads ;; agentset containing the patches that are roads
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! ~! `6 C& ~( ^' I2 `- c/ j/ @1 Nturtles-own1 V k" |) A3 z
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# [" f1 |. y. x6 {3 @' k# P speed ;; the speed of the turtle
8 p! \( q: f7 T; P' j- [ up-car? ;; true if the turtle moves downwards and false if it moves to the right
* _* E/ \6 @1 E6 ? wait-time ;; the amount of time since the last time a turtle has moved# V. g: x" O- M1 ?5 K
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads! W( A6 k6 H r' p4 ^7 a# E
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
7 G4 Z8 v5 f+ l' S" { ;; false for a non-intersection patches.: b3 [5 U( r2 E: Y2 v. P1 p
my-row ;; the row of the intersection counting from the upper left corner of the2 T# u# h5 q8 |, R# k3 Q! e% o$ b1 K
;; world. -1 for non-intersection patches.
7 j. [! o$ ?- I my-column ;; the column of the intersection counting from the upper left corner of the; N: s. k2 M5 x* T) Y) g
;; world. -1 for non-intersection patches.4 P3 r) F- w9 {' D3 k6 v8 `4 g* x
my-phase ;; the phase for the intersection. -1 for non-intersection patches.; d( G) E- d% R8 D4 H% `
auto? ;; whether or not this intersection will switch automatically.
) x6 E2 d4 L2 q' k3 O3 z; ] ;; false for non-intersection patches.4 m, L$ E) u9 ]0 W( J! d$ R
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;;;;;;;;;;;;;;;;;;;;;;
" v8 m; E+ b* Q9 k9 I c8 E3 @$ L3 t;; Setup Procedures ;;
( K: z# W+ Q! O3 v R" d2 ^8 f;;;;;;;;;;;;;;;;;;;;;;5 i9 F5 r& x4 T# ]
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;; Initialize the display by giving the global and patch variables initial values.+ M3 G/ P' s/ ? X. i8 ]+ w) x j) Q
;; Create num-cars of turtles if there are enough road patches for one turtle to; A$ f" X9 f8 w( s8 f+ s
;; be created per road patch. Set up the plots.
) z! z1 x+ k5 Sto setup
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; [% Y, P# ]+ G+ p setup-globals
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;; First we ask the patches to draw themselves and set up a few variables( z2 {% X7 G7 ]2 s( L
setup-patches
+ K* E2 C2 N. q' f4 J$ ? make-current one-of intersections5 M: }9 {8 P ~; ^6 h ^
label-current* A, L: T8 `& w5 s. T1 q& w
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set-default-shape turtles "car"- B- D; b6 e! h2 D; K
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if (num-cars > count roads)' \. N# L3 `. q7 U
[
! i$ Y$ ?8 T. _, L9 [! e user-message (word "There are too many cars for the amount of "
5 |. U- U4 b6 ^. H& J G "road. Either increase the amount of roads "6 \4 f5 B! y/ ?/ E" a. k$ n+ n
"by increasing the GRID-SIZE-X or "
- Z# y b; ]3 E. y$ }9 U2 |0 W' ~ "GRID-SIZE-Y sliders, or decrease the "
. ^; I$ ^6 R: m) T: k& R "number of cars by lowering the NUMBER slider.\n"# @/ X/ S7 B- }, o
"The setup has stopped.")( Q7 s- T7 P. o, k& M M! z) ~
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color" @' f- M, h7 b2 p9 j+ j& G% n
crt num-cars
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setup-cars: A! v, z+ `& M2 \1 K. J9 P1 h, s+ \
set-car-color
, m( Y& k. K8 }1 b record-data
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;; give the turtles an initial speed
8 g8 ~- W( g2 f( ]# a. I ask turtles [ set-car-speed ]) [) {$ P2 @* z4 Y5 n2 l7 X6 x* t" O
5 \4 k r$ U7 w reset-ticks
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4 l. j- m( z0 u1 q5 z;; Initialize the global variables to appropriate values
% d( _8 a% l, t, {/ gto setup-globals
4 ~+ f% T6 I, s# ?2 l# w/ ` set current-light nobody ;; just for now, since there are no lights yet. Z5 n2 R, j$ H3 I! x$ e
set phase 0# K' G- R/ v# g; y
set num-cars-stopped 0: L M' @" W H/ s4 y9 I9 l
set grid-x-inc world-width / grid-size-x6 K n$ r& {( p. e( c! b+ K; w( e
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
* H& \5 F- L& j" f c% s- D set acceleration 0.099
( M" Y* Q4 m+ e9 q6 U; e8 D1 g* Z: Jend
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" d+ F1 J' Y4 A Y; c;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
# w6 \! b$ n& s( g6 d;; and initialize the traffic lights to one setting
( N2 F ?& J. |, S8 g3 @* r! a- Uto setup-patches
- M8 z1 S, T5 ?$ x& L3 W ;; initialize the patch-owned variables and color the patches to a base-color8 x5 h( X$ C% Z3 L1 ^1 ^* C- ?
ask patches/ q. r/ R0 M2 S7 j' Z6 w
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4 Z& J' J C Z4 n( d6 Y set intersection? false5 x5 K, q$ l+ ?" R; A1 S
set auto? false* a; p3 s/ x* g* M
set green-light-up? true$ U; A, b3 @; ?7 v% [
set my-row -1! G& G& @8 y) r. @9 c$ H4 M. Z
set my-column -1' o6 p$ C% J' ?9 T
set my-phase -1
- o# F8 L3 ^2 g9 u4 |1 \! D set pcolor brown + 3
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: b7 Q( ~( J& h: s ;; initialize the global variables that hold patch agentsets
; J3 s4 n0 T, T set roads patches with
" u" J: Y4 s$ R$ C; k [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' w5 n6 V$ |) j% ?7 s (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 s2 K/ \3 L1 A- u/ ]/ S! q1 p
set intersections roads with. T$ W9 m, ]; Z' g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
9 ^- T, n/ V8 v { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]# t' `/ i1 r' i( k* }
! o5 v1 P" g. ` ask roads [ set pcolor white ]
+ Z; m& w) Q0 T setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?" C; o4 G1 J" s" _, S
set roads patches with
2 H2 O' H- _+ S5 I2 g" x* U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) t L9 ]; F, _9 P* @9 J) m
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! {8 J" y! K( R8 O0 Q
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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