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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。2 V7 Y7 e* ] j* y( p
netlogo自带的social science--traffic grid这一例子当中,
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4 l+ n% m1 d3 r" X. `1 h6 A" ] grid-x-inc ;; the amount of patches in between two roads in the x direction+ t) [0 b- A. s* H+ ^3 b
grid-y-inc ;; the amount of patches in between two roads in the y direction
7 W3 c$ s. W2 k Q, { acceleration ;; the constant that controls how much a car speeds up or slows down by if
5 z+ ?2 Q# ~% [3 @1 `! u+ a ;; it is to accelerate or decelerate3 b F! [+ B+ h1 B C- ~
phase ;; keeps track of the phase
# m, \: k8 f8 H& S5 w* r% `8 x( h num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
* S% }( J8 o8 [2 S* S+ b U current-light ;; the currently selected light; K$ h0 j4 v- a: E& ]. H
3 E$ P0 F) |1 g9 n, h4 b' A" w/ V$ L ;; patch agentsets
; K3 h _0 d2 d0 p- ^) L$ S intersections ;; agentset containing the patches that are intersections! c0 b5 z8 [: ?
roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle
1 M/ v9 s" Q0 J" | up-car? ;; true if the turtle moves downwards and false if it moves to the right3 `# Y; a9 z h/ V" [6 R$ B; i s
wait-time ;; the amount of time since the last time a turtle has moved3 Z+ s, ?, j0 P2 c
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5 m! e4 u. I F( Opatches-own9 `+ I5 I8 {7 \; L
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intersection? ;; true if the patch is at the intersection of two roads$ I5 J5 [8 C. m- M1 ^: U0 O
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
# V/ c. n( e' p" A* | ;; false for a non-intersection patches.) D5 G1 Q9 V& y) r/ }0 w, Y4 j
my-row ;; the row of the intersection counting from the upper left corner of the2 B# m9 k9 \. R! {( L+ Y' |
;; world. -1 for non-intersection patches.
2 G9 Q/ o( n. { my-column ;; the column of the intersection counting from the upper left corner of the
8 Z3 j' D* Z9 p" t" P0 }9 O5 ~0 X ;; world. -1 for non-intersection patches.
4 @+ ~5 E& H5 Q Z0 ?8 r* R" C my-phase ;; the phase for the intersection. -1 for non-intersection patches.9 z. m5 w% t% w3 V& k
auto? ;; whether or not this intersection will switch automatically.4 _. h# E! Q, t2 l( l' n/ F- t' k+ e
;; false for non-intersection patches.0 B4 W3 o. U0 w0 `
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;;;;;;;;;;;;;;;;;;;;;;8 i1 `% O- S! m9 N% H3 t
;; Setup Procedures ;; E+ v ^" d h9 H$ l
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2 B8 k k: V4 @- t- @0 N;; Initialize the display by giving the global and patch variables initial values.
4 T" o& K& d( h( q* {2 S! };; Create num-cars of turtles if there are enough road patches for one turtle to* E. N! r( b: f( W" H
;; be created per road patch. Set up the plots.
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setup-globals- ?2 `: s1 i' p* j+ F
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;; First we ask the patches to draw themselves and set up a few variables) U- Q, R# \1 C5 ?- p5 [
setup-patches9 G8 \* i* y" M4 I. q G
make-current one-of intersections2 q! c8 Q$ e1 ^# p& q y$ B" i2 F
label-current
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set-default-shape turtles "car"
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$ W: ]& s# m+ x if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
% @$ y2 s, H _" {, C "road. Either increase the amount of roads "
" b7 ]$ {9 p6 A. I# K& ~ "by increasing the GRID-SIZE-X or "
& S, F% Z }# Q* T "GRID-SIZE-Y sliders, or decrease the "& O+ z W2 i6 v% G
"number of cars by lowering the NUMBER slider.\n"+ Z' w% f% R" N
"The setup has stopped.")
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5 }1 P) Y3 a$ \2 i. N( T- [ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color4 \" J2 R& j v/ u1 D
crt num-cars- M2 y, }5 T8 N$ q# p, r" J0 v
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4 }( Y H7 q- c0 n# g setup-cars& A& [* `8 C7 N3 h! e+ ]# S" r1 f
set-car-color
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;; give the turtles an initial speed
/ H% }. s5 R! d0 y5 P ask turtles [ set-car-speed ], M0 n" N* S4 U5 }/ D
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reset-ticks
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5 `$ Q$ C U5 l;; Initialize the global variables to appropriate values
: T8 w( t, |; w0 i# v2 @to setup-globals x7 C. _4 v& T
set current-light nobody ;; just for now, since there are no lights yet# _6 a: Q3 ~/ W
set phase 0
8 l$ F6 U9 f* z set num-cars-stopped 0
N. [! D9 s9 J' v% N7 w+ g set grid-x-inc world-width / grid-size-x
& I, B& d, y$ E& S3 W" s set grid-y-inc world-height / grid-size-y& {; t; }) p H
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary' f( b( u+ H" [$ j$ D& V
set acceleration 0.099
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: ?! ~2 ?6 O9 G8 i' L" U7 L;; Make the patches have appropriate colors, set up the roads and intersections agentsets,: Y( g. g$ J- K, t c# u
;; and initialize the traffic lights to one setting
; m( \+ s0 n4 Q5 [ W& O" fto setup-patches: y* S7 M8 W% I4 n* e
;; initialize the patch-owned variables and color the patches to a base-color
5 O4 Y O( c9 t' X Q; X$ [ ask patches3 z6 \+ m: f6 ]& B0 u
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set intersection? false5 J% s- J4 n1 C+ `6 [
set auto? false0 B/ _+ N2 P9 R) j- v
set green-light-up? true
$ V" l6 B; ?# B. A set my-row -1
( m9 d5 ?9 J5 B9 ]+ g: W* U set my-column -15 d. D+ S, u7 B% B9 B
set my-phase -1' e3 c7 k! Z( G+ }9 Z9 v
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
2 O& N g( P4 b5 H/ ^ set roads patches with N: U( f) g/ g4 @( c) b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; r, B. I6 f* q# K
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 T; |; ]8 `1 A/ i set intersections roads with
7 {. g' l( R- n! n5 W5 |1 G [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
# s W/ M: u' j" r( ^' K& i (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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9 \# O2 ^% E* X' G, ]+ U) F% k ask roads [ set pcolor white ]1 r& F% k# }- {! z0 e" @
setup-intersections( t0 O3 I: P2 l" F
end8 ]6 F# w! X" Z! g* k/ T- }6 m) z
其中定义道路的句子,如下所示,是什么意思啊?% ^4 H# v1 \9 Z3 ?5 C$ _+ _
set roads patches with
& {+ M; k2 }! ]1 H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 }: t; w$ E/ y/ F: q9 i8 a! V. e (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ y. d7 B5 f1 @; \7 `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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