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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。+ R9 b& A( {0 |1 {4 e: }
netlogo自带的social science--traffic grid这一例子当中,7 X k# b2 Y; m6 q
globals8 f5 _" o3 Q% v* a6 f
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grid-x-inc ;; the amount of patches in between two roads in the x direction. e; M; d2 K4 A- y, |4 g# c; |, r
grid-y-inc ;; the amount of patches in between two roads in the y direction/ j) c7 \4 f& t! N+ w& g
acceleration ;; the constant that controls how much a car speeds up or slows down by if9 L) e' B) J4 g/ H
;; it is to accelerate or decelerate) r5 I3 u4 x, W5 |
phase ;; keeps track of the phase
, _1 p, f6 x' a' L1 _0 z num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
5 @) j, t7 I% f% ~ current-light ;; the currently selected light
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;; patch agentsets0 o9 H ^. G% {/ S$ L- |, a- _
intersections ;; agentset containing the patches that are intersections4 {+ j$ p9 T5 {' `+ P
roads ;; agentset containing the patches that are roads
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turtles-own
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, @4 o. X8 E" C/ U' P/ L speed ;; the speed of the turtle
/ Z9 \0 `; s% I; O& f+ ] up-car? ;; true if the turtle moves downwards and false if it moves to the right* X8 x/ k* @# U. o$ P
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads: r9 f6 A5 l3 m# v* [4 d, R' h9 ^; W
green-light-up? ;; true if the green light is above the intersection. otherwise, false.3 H3 n* H ]7 S e% @ Z
;; false for a non-intersection patches.
# I* V; r U" L my-row ;; the row of the intersection counting from the upper left corner of the
( R. D. b' c+ w4 W0 \. h; M1 {, k ;; world. -1 for non-intersection patches.( n8 H# D! Q3 p8 }/ }/ s8 h8 K, ^# Q
my-column ;; the column of the intersection counting from the upper left corner of the
; s( r2 }) I1 c ;; world. -1 for non-intersection patches.
% E0 I/ u( U' C! e7 g9 \ my-phase ;; the phase for the intersection. -1 for non-intersection patches.: M" S- Y) I, J! R7 }) x
auto? ;; whether or not this intersection will switch automatically.% |2 j2 a" M' z9 S! B% @
;; false for non-intersection patches.
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- ?+ |% `; ?, V;;;;;;;;;;;;;;;;;;;;;;
0 O! l0 Y0 W4 K% f/ }" v;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
; O* o; _" N; R9 m& i;; Create num-cars of turtles if there are enough road patches for one turtle to6 S$ N* e, a3 T' u5 n; P! l' x
;; be created per road patch. Set up the plots.9 @ D$ D' E- B8 N# d( D( A
to setup
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/ F; h+ Z9 J$ Q setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
# \5 L( @$ b- | setup-patches
. M _! r, l( G) E$ e+ y make-current one-of intersections
# M3 y* |' y5 S" t: K6 e8 Y label-current: r6 {6 E. P0 m* v. q: I! X
/ }0 P z, u, k% s \3 S0 N set-default-shape turtles "car"
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if (num-cars > count roads)" e2 `) O- X' x' p2 g
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user-message (word "There are too many cars for the amount of "4 J: v* I7 t/ _. h
"road. Either increase the amount of roads "2 T M8 y8 y6 t. u% ]) H8 u
"by increasing the GRID-SIZE-X or "7 F) t3 \4 A% d! K! F |, V
"GRID-SIZE-Y sliders, or decrease the "
4 ?$ ^: O# D+ f, ~ "number of cars by lowering the NUMBER slider.\n"
' t5 k& |' ~: ^" e, z "The setup has stopped.")% Z/ r1 p* f% w0 P
stop# r7 Z( S6 P& [$ o; Y* d$ s$ i
]
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color) g* `# S& g5 R7 [0 Y) `/ U
crt num-cars8 I5 ^- _( z. _ ^$ T6 }2 @
[
2 w7 `6 E4 A5 |% G6 n* j setup-cars3 p! ~( w; k( w+ y- o) T
set-car-color
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]
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3 L. H, i d. N9 U ;; give the turtles an initial speed
- f6 y0 r" A. j ask turtles [ set-car-speed ]
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1 E" U' P% l) P: q9 a reset-ticks
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3 p L6 e3 ?; v6 g9 [" d;; Initialize the global variables to appropriate values' o3 e. ]+ G2 i+ p5 ?1 k( ^. f/ k
to setup-globals& {: s3 r, ~+ \7 `1 \
set current-light nobody ;; just for now, since there are no lights yet
+ F4 Y: A1 w9 o4 ^1 s set phase 0" F# n3 C6 C! Q' X' e. u! s3 l
set num-cars-stopped 0
$ n& }9 I, o4 Z6 j$ K! n set grid-x-inc world-width / grid-size-x1 l" T: D/ E G5 M% g8 V. s. q
set grid-y-inc world-height / grid-size-y$ a2 c) k" J& ~' y' c
* M7 G" M8 t. u, b ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
! c( i0 ~( Q' x9 K4 H! X set acceleration 0.0993 R. S" M+ N) j. O* A2 K
end7 h8 ~) C* M/ _) r5 G( p
' \3 k: B! w: ^) R# [. h;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
5 C9 f- n$ ^: X1 T' C;; and initialize the traffic lights to one setting Z7 p, B) a+ s) \! r0 `
to setup-patches
* O- ^+ u. z+ ?0 s3 M ;; initialize the patch-owned variables and color the patches to a base-color
* h. a t, Z: q: w6 A- z2 _" F ask patches
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set intersection? false: R8 @' d/ g- r* R/ |0 }
set auto? false
7 Z6 u/ Q: ^2 I set green-light-up? true6 x5 c- }7 j% d% h8 w
set my-row -1
# O. e: I3 B: J0 B8 p( t set my-column -1
+ k2 A6 m z2 @$ y. m: G) D set my-phase -1
J! B7 L _ E4 n; U) z& k set pcolor brown + 3
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7 g$ g0 o \0 j* K' R0 l% Z ;; initialize the global variables that hold patch agentsets
# L9 `) D) }# }- E4 F9 a set roads patches with
, i, w( a/ A. ~1 Z! M [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( q: c8 K/ A0 @* D
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( f: S( |7 x' r. _4 u* O set intersections roads with; { n' J$ O. b$ S9 ]7 x, H. b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and8 q) p( @ @, E7 w
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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6 M# l8 i8 W- r- o1 F ask roads [ set pcolor white ], k. |0 \) `5 y4 n( ?
setup-intersections4 n# b! Q& H; Z
end2 Q! e! b4 |& i8 @+ b% r4 h
其中定义道路的句子,如下所示,是什么意思啊?
5 V% | C, D2 t set roads patches with
" u( V- i5 f: W g4 B8 E: H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 k% b! g& v K5 l (floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ {$ y1 A: t# [% @; e% R
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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