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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。
& s! ~( u- t; f& y, m2 W- enetlogo自带的social science--traffic grid这一例子当中,( W) `% Y' Y/ v- V! {
globals
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1 i: S9 u9 e4 y/ |2 j5 w$ A grid-x-inc ;; the amount of patches in between two roads in the x direction
! H) K% p8 g# `# y: b& e8 H1 q grid-y-inc ;; the amount of patches in between two roads in the y direction
% k6 d- ?6 x# {2 G5 j- J acceleration ;; the constant that controls how much a car speeds up or slows down by if
# g2 c; H6 C6 L9 Z t; k ;; it is to accelerate or decelerate
( Y6 c5 v9 }" f. a) A5 \) _% Y) f) K( x phase ;; keeps track of the phase
; j3 S; [/ e( r/ k num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
+ d6 Y! H/ n3 r/ M( Y& Z& G! f current-light ;; the currently selected light
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$ X) @4 O" h. g ;; patch agentsets
9 j3 z4 ^/ q$ B9 t intersections ;; agentset containing the patches that are intersections
2 c4 U# P9 o' s* e$ t roads ;; agentset containing the patches that are roads( N. e$ n u* p4 R" k
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turtles-own3 C; E/ c2 P# G8 V" Y' J
[
3 w' g; k3 b2 z' z4 Z$ V3 b8 |- R% \. m speed ;; the speed of the turtle( c8 A+ o \9 i' e0 C! U
up-car? ;; true if the turtle moves downwards and false if it moves to the right+ g) v/ l7 x$ G2 B' q( m4 y
wait-time ;; the amount of time since the last time a turtle has moved- f" C9 x! M$ c' K- @2 {
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" q$ F; }1 W% q5 _5 ^$ P3 c8 q+ L% ~patches-own; ` N' G! l( k+ P5 g2 F, Z
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intersection? ;; true if the patch is at the intersection of two roads) `! Q- `* M% x6 m- G! G
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
7 U3 s5 `4 d! R6 c1 w ;; false for a non-intersection patches.
) t( P) i( i( L- D( ~, a2 n my-row ;; the row of the intersection counting from the upper left corner of the
; g( _6 O! {% h7 x ;; world. -1 for non-intersection patches.
7 a+ ^) p+ q6 a! k" S" Y my-column ;; the column of the intersection counting from the upper left corner of the
- q- }$ ]0 U- e4 O" Q ;; world. -1 for non-intersection patches.
& R; C6 _2 j% `9 ]3 w! ? my-phase ;; the phase for the intersection. -1 for non-intersection patches.
2 R3 r9 u8 | F" Q auto? ;; whether or not this intersection will switch automatically.4 O; B, f- K$ l* ?0 P; `" V8 V9 D# B
;; false for non-intersection patches.1 C$ y6 z r2 G8 l2 ^% F# G! n
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3 D1 v7 E5 u: ~ F" \. `; d1 W5 H;;;;;;;;;;;;;;;;;;;;;;
. | s$ W. g2 u, _5 F7 L7 _ ?;; Setup Procedures ;;! t) y, ` Z; b! z% |
;;;;;;;;;;;;;;;;;;;;;;* M6 N- q) v! t* u* j
2 R6 K4 H. M! j' a4 K;; Initialize the display by giving the global and patch variables initial values.
+ ]3 X; W) g" j2 |5 S;; Create num-cars of turtles if there are enough road patches for one turtle to/ y# ^ P" `6 B7 b: O: V
;; be created per road patch. Set up the plots., n9 k: ^2 q+ F( F4 Q
to setup( u- B! D% M6 f! x0 S& y8 \, f
ca
( {' T) o8 L j B! [0 { setup-globals- x; J% j/ \0 k1 F* Q, q
6 [- q K/ t9 l; L ;; First we ask the patches to draw themselves and set up a few variables) G; q. l7 s( Z/ F5 ]
setup-patches/ K4 b8 x3 y: s* L
make-current one-of intersections* ], j9 m$ u+ b: G
label-current0 i; ` W( w. d% I2 F m5 F
% C7 G. c7 @1 | set-default-shape turtles "car"0 M$ y$ }7 h* R3 a- G
% U6 N% Y# t: z# z- A: A if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
# Z0 ~7 p3 L" \2 q "road. Either increase the amount of roads "
* o0 Y5 X- p' [2 n3 J! w "by increasing the GRID-SIZE-X or "8 m. a( {2 a" V5 K3 ]+ h
"GRID-SIZE-Y sliders, or decrease the ", F5 Y6 \, _/ @' z0 e* c
"number of cars by lowering the NUMBER slider.\n"! ?/ i( Q* }7 }3 S2 ]$ A1 n& l, E) I
"The setup has stopped.")% g% X' m. z2 O9 P+ I! f/ w
stop) m+ n' A" h. r9 p- R) |0 K1 V
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& c! w6 N; H: N( m5 @3 s ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
+ C0 p, ^* H3 X9 d crt num-cars
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W. ]6 M; u$ s, ~2 A7 V' S$ K setup-cars+ f4 T, V# P* `" Y
set-car-color, z9 a- ?, w1 `2 g/ e1 G" I) e
record-data. s. G4 F9 r% ]# x8 t
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;; give the turtles an initial speed
, z8 s& A3 f( V" n9 K$ s) J8 ~ ask turtles [ set-car-speed ] d! S/ u! b) m
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reset-ticks
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
, `7 s/ T4 ~ D V2 S set phase 0
9 F/ B* u. K2 s" ~2 l/ r set num-cars-stopped 08 B8 u* U% W; z6 ]" T @
set grid-x-inc world-width / grid-size-x2 r1 x! m3 ~3 m
set grid-y-inc world-height / grid-size-y: l. k0 E, d9 O. N$ r. S. ]
- B8 V- n0 x) W1 A ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
% w7 R9 a+ P; d7 i set acceleration 0.0994 F1 p* Y; j8 }3 Q
end
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) J) }- w/ a/ j; V0 d7 m$ L;; Make the patches have appropriate colors, set up the roads and intersections agentsets,8 b! E8 m" k6 G) j' |4 M
;; and initialize the traffic lights to one setting+ @; R0 n1 }6 M7 o7 M* G7 g
to setup-patches% ^% M" I4 J. i+ e( [* N
;; initialize the patch-owned variables and color the patches to a base-color
, P) y3 `+ j' ~/ `" L/ y0 Y+ ]* ] ask patches
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' w, `9 V, T7 ~8 ` set intersection? false/ r" a: H: m: h" c- ^: x4 x( g: b
set auto? false1 Y& o4 _7 Y0 c0 b& b: O
set green-light-up? true0 C% N5 m) W8 n& J, I( @
set my-row -12 L3 |1 M8 i, j
set my-column -1
/ H$ P g0 |& B0 T+ Y& ] set my-phase -1
( ?8 _! D% C5 y7 O7 N set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
1 Y, n& r" ^; c; x+ T" k# \ set roads patches with$ D& R% K, y* [9 A" e/ {' @- c) Z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# m6 S, @5 A# n* c
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 I5 d% t; t, p, v8 u; s0 X
set intersections roads with+ U4 V$ d6 I/ m) I, B/ p1 K7 ]
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
! S- u$ O# S' z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]. R: ?5 E! e' i" W" u% }
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ask roads [ set pcolor white ]8 g9 N- @/ }/ O4 A* o7 G* e
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?
! j' D2 T$ x7 | F set roads patches with
$ x4 m2 L' e$ e4 b9 {8 c, ? [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 X" K5 ]0 O( I7 u5 y0 ?
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ M# N! L1 D$ v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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