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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。/ X6 B6 Q& ~$ [0 T2 O6 \2 ?
netlogo自带的social science--traffic grid这一例子当中,
7 p2 W$ H( B( [globals- O$ j: A4 }' h4 W o+ P
[
4 f- v7 f6 b* d! d1 C4 D( \4 I grid-x-inc ;; the amount of patches in between two roads in the x direction
+ k) C4 K- _7 [$ v# j- R. J! m1 U grid-y-inc ;; the amount of patches in between two roads in the y direction/ C D, E" W4 e! }! X
acceleration ;; the constant that controls how much a car speeds up or slows down by if- M. U, z6 b1 y9 V, \, Q
;; it is to accelerate or decelerate8 d& x6 i( L4 S& J% e; f
phase ;; keeps track of the phase
' v+ d, G$ w. e' G6 ~ w+ _ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure _% m' ]( L( @( F4 W: j
current-light ;; the currently selected light) X: {6 J9 P$ o3 {) C8 Q
- m4 t! d9 W v* G* s3 V- ^ ;; patch agentsets
# Q) R& g1 A- C; U; m3 z6 Y- c$ ` intersections ;; agentset containing the patches that are intersections% m6 A* {% M& T7 v+ m
roads ;; agentset containing the patches that are roads' D+ E& o( \: N, A) f7 L7 T
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turtles-own. K9 R# a2 t ^3 \' u+ N: T. \
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& h. ]2 V5 D8 H, D' z speed ;; the speed of the turtle6 M3 t& g4 e1 H e! ~+ }8 A7 F
up-car? ;; true if the turtle moves downwards and false if it moves to the right9 O# M; w$ `. y7 ^+ |6 H
wait-time ;; the amount of time since the last time a turtle has moved
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1 K% Y+ J8 W# R6 x0 {patches-own
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8 s1 y/ c: i: N, v intersection? ;; true if the patch is at the intersection of two roads
# M8 T: t0 ~* j, G3 x2 m green-light-up? ;; true if the green light is above the intersection. otherwise, false.0 m1 K0 ] c6 _9 t& {- }
;; false for a non-intersection patches.
* s6 E6 i, s \2 j% ? my-row ;; the row of the intersection counting from the upper left corner of the- Z5 Y- h) B% J
;; world. -1 for non-intersection patches.
( i+ k; d; |3 x+ b2 d( N my-column ;; the column of the intersection counting from the upper left corner of the; D9 N* m! P0 F& b5 [
;; world. -1 for non-intersection patches.8 v% v9 O5 W7 d! S
my-phase ;; the phase for the intersection. -1 for non-intersection patches. `& d, r3 @- d% v; |* B
auto? ;; whether or not this intersection will switch automatically.' m/ W: \" ]: _( X3 }
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
. o) h# [5 I$ X4 b: o;; Setup Procedures ;;- G3 C& U4 s% w+ r5 `( q
;;;;;;;;;;;;;;;;;;;;;;
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0 o& p) L1 a) [, v) k! b% B, V;; Initialize the display by giving the global and patch variables initial values.
$ x& J( N8 J- P;; Create num-cars of turtles if there are enough road patches for one turtle to: H( L0 |5 F7 X! X) j( M
;; be created per road patch. Set up the plots.
' Z, V7 y; z7 i* x$ hto setup' p1 _# V& G; c( h; z" p: v6 L
ca
7 k- R) j9 d0 J: m- d1 s% l' T setup-globals
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;; First we ask the patches to draw themselves and set up a few variables; n# v5 I$ s0 w1 C, t7 o
setup-patches* F" l- g9 ?1 X' U- u b8 r
make-current one-of intersections" w* U1 c+ Y8 O- |# U
label-current/ Q3 v0 E* r) ~
! S9 D8 F4 k7 x1 U$ S0 v& t set-default-shape turtles "car"
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* p. X( G6 |; N2 i# y if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
3 w+ `! h1 V2 m8 K "road. Either increase the amount of roads "
/ s& H" v1 T+ ? "by increasing the GRID-SIZE-X or "
! g X0 k1 {% p "GRID-SIZE-Y sliders, or decrease the ") A& ^3 ~" r9 L" }! \+ G
"number of cars by lowering the NUMBER slider.\n"
: V v% }& l/ B; y" ]: s. j& m "The setup has stopped.")8 j( q) S: O W9 s) N
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color$ f+ D! i/ F* L& Z. y0 R
crt num-cars% ?! i& Z2 C7 c
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setup-cars
, F. f9 p$ S4 k! T* d set-car-color
9 w$ I& j9 E d( `: B( B record-data
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6 n0 V! r/ y6 m- Z ;; give the turtles an initial speed
6 s! e: \6 h; W/ x/ B+ ? ask turtles [ set-car-speed ]; J L) M( B+ V* _; ?0 P
* h @$ Y+ T* }3 W9 J# v6 b# i% N) }
reset-ticks
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;; Initialize the global variables to appropriate values# Z/ l$ P7 w8 q$ K
to setup-globals% B' \3 t2 H) ~
set current-light nobody ;; just for now, since there are no lights yet9 I; K, L! D. t$ s
set phase 0
9 y- H- b' a2 a; Y, m( ~9 `+ K set num-cars-stopped 09 D7 g2 |6 c: ~
set grid-x-inc world-width / grid-size-x# T1 i# S+ v3 [2 d6 X6 r
set grid-y-inc world-height / grid-size-y3 R# t, I3 E1 ?
0 u) r2 H; f& A ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
1 r6 |9 z6 c q/ L' n5 o( c( V set acceleration 0.099
& R" ?, A1 e+ pend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
; q0 Z: U/ M/ q2 Y, h5 ]! Y;; and initialize the traffic lights to one setting
9 ]1 r% B7 ^1 s1 w0 Hto setup-patches
5 i0 W+ \0 h& i1 Y$ y- ` ;; initialize the patch-owned variables and color the patches to a base-color
( |0 t( {4 e; L% W9 S: u ask patches' [. F( H2 T+ { \8 |) ]) c# ^& t
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set intersection? false, o7 Z$ E& E V( w6 w9 [7 ~. G3 K* s
set auto? false
: ^5 {, E2 i0 `0 d set green-light-up? true
% {; i ]- D& ~9 D, m T' o set my-row -1) } @) c( t7 |9 F- @
set my-column -10 u# e: O( n! Z' r6 K4 J3 o* W
set my-phase -1
( ?* f5 Y: N4 L$ G set pcolor brown + 3" |& h! c6 l, h I
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;; initialize the global variables that hold patch agentsets
! |3 x, e$ U4 \4 `' a# { set roads patches with
2 G7 q2 o& H x# X [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( E+ k) s/ v5 U" ?( C# m5 |% e
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ V% `& P" ~3 k' W) z* q! g, T
set intersections roads with4 o# V1 |* w) e( Z# [7 F
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 Z) i I, W( G$ A; E( Y; F (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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5 w% Q4 [! E9 t/ o8 v; L ask roads [ set pcolor white ]% `1 h7 G/ @3 E, i9 k
setup-intersections# I4 H/ v; d4 U) F5 Q( C5 _
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其中定义道路的句子,如下所示,是什么意思啊?9 Z1 N4 Z9 T0 [4 |9 _
set roads patches with
0 g% o) ^* O& r. a( U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! Z& s% H( z" ?
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 a7 u1 m! I4 J) o
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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