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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。" C4 M" x+ A; X6 z" D
netlogo自带的social science--traffic grid这一例子当中,
+ K2 ~( R8 V [) U Aglobals' Q& s1 a& P6 G! A" s
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/ P+ g- O6 j1 R4 R grid-x-inc ;; the amount of patches in between two roads in the x direction, d9 J9 K6 I( ^* n
grid-y-inc ;; the amount of patches in between two roads in the y direction$ ` p( ^2 S' h" p! T# ^
acceleration ;; the constant that controls how much a car speeds up or slows down by if
5 O& k$ k% B; ?/ w ;; it is to accelerate or decelerate
% C: t2 u, j2 V8 }3 y phase ;; keeps track of the phase5 |$ O6 \" H% M. Z/ F
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
9 l z. o, X9 S current-light ;; the currently selected light7 g2 ^9 C! _8 u
1 @# u7 s% G, y$ l2 |+ ]5 M$ Y2 G ;; patch agentsets8 Z5 O. G1 s& d. l& i& s; i! S: c
intersections ;; agentset containing the patches that are intersections
# e* u3 W6 H& _ roads ;; agentset containing the patches that are roads
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3 E5 k% m0 u8 b1 k2 J# jturtles-own; Q! r$ u$ n$ x. ]
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- `, M9 I2 o- k speed ;; the speed of the turtle% G( M% V+ b3 A# h( U0 w' W
up-car? ;; true if the turtle moves downwards and false if it moves to the right4 Q8 l% p8 h$ q0 A: z6 M8 V5 K
wait-time ;; the amount of time since the last time a turtle has moved
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. o; G5 t [( m: w; F& C" B, Jpatches-own
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intersection? ;; true if the patch is at the intersection of two roads3 |2 \) D* O6 s ^) K7 {: l
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
- a9 g/ F8 f0 Q( [( q ;; false for a non-intersection patches.
$ p/ ~# A) O+ `3 ^# ]8 x my-row ;; the row of the intersection counting from the upper left corner of the
! g4 j! M1 ]. g& d% z1 t ;; world. -1 for non-intersection patches.# ]; k6 a' \' w4 z+ _
my-column ;; the column of the intersection counting from the upper left corner of the" f* E; {. d( D5 ]
;; world. -1 for non-intersection patches./ @1 H) s& Z8 \; _/ n0 d
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
) v; c/ W% P/ v- a% V# x auto? ;; whether or not this intersection will switch automatically.
; O3 g( ?1 a; j5 X6 W J ;; false for non-intersection patches.
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0 }5 v$ q' ~) e;;;;;;;;;;;;;;;;;;;;;;
: n7 V8 Y1 X, r;; Setup Procedures ;;
* a6 C6 b) l a9 p7 F* Y4 `; Z% ^;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
+ q1 D# s6 d% ]+ W$ N4 j# }$ l;; Create num-cars of turtles if there are enough road patches for one turtle to
% Y4 Z& o8 L2 A& m& U4 m, `;; be created per road patch. Set up the plots.
, H+ m K! a* I& k9 h, p; Ato setup
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7 g# v1 p! M/ b setup-globals
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;; First we ask the patches to draw themselves and set up a few variables3 M! V6 q8 }" \/ t7 Z. k, G7 ^& C
setup-patches$ x2 Q2 h |5 }, l! W+ ~( V6 ~
make-current one-of intersections0 ^! G1 }, G- N, X; e
label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "4 }% X$ X, C; W/ P% ?2 @! Q
"road. Either increase the amount of roads "+ `- |' x1 i3 ^6 c% T! y* u7 b
"by increasing the GRID-SIZE-X or ": {. i, m S) c3 ^
"GRID-SIZE-Y sliders, or decrease the "
1 _$ L( [0 G& f/ g$ B9 c: H! e "number of cars by lowering the NUMBER slider.\n"
& W% G3 w- R" t "The setup has stopped.")
, G, U1 L Y0 K( a stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color5 W2 a* x: p) J1 h% O) `- k' ^
crt num-cars. T7 N2 g* H- l2 V2 K" Z
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) v8 Z! t. I @7 d% z, C- J1 w8 Z7 j7 m setup-cars
( D! R( C& Y3 w4 d, x set-car-color: w& v% e+ I' P) A" ^. R+ R
record-data3 i T% i* g* d Q$ h) U
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;; give the turtles an initial speed
; @8 O( c' \* r ask turtles [ set-car-speed ]0 e" Z+ A: }( \. b) S' @
/ u1 p# [7 U4 x* _1 X reset-ticks
" ?) u# Q# O) j. l/ f# P( Rend
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) m' y) d; U5 S8 s, M;; Initialize the global variables to appropriate values
9 x% o9 t$ D w% l# {& _" Sto setup-globals
$ u! H0 W, C2 a, b/ Z% e" Y set current-light nobody ;; just for now, since there are no lights yet
9 Y$ l& t$ w2 i4 x set phase 0
9 L) k r% V5 d6 L set num-cars-stopped 0
! W1 Z8 B: ^! t9 w3 ]* h set grid-x-inc world-width / grid-size-x* w5 R9 @) k) i+ o9 E$ U
set grid-y-inc world-height / grid-size-y9 w5 T& o6 @& ~6 n
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
) S) e( J7 s e: p set acceleration 0.099
: ^6 \: S" s F# fend
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# H5 e* A4 _" C1 Z b/ B4 i;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
, C- x9 x) W) E) ?' _ };; and initialize the traffic lights to one setting( ?6 _# a( n& J! I
to setup-patches
% J( U. |4 b" y' L/ @ ;; initialize the patch-owned variables and color the patches to a base-color
2 p$ m0 R. x3 ~ ask patches- q7 ]) P: p" ]( e% a" F& `
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set intersection? false
# B5 _% E+ g2 j+ f2 E0 C set auto? false+ t6 @# U, f; ]" v: R& M! J) L
set green-light-up? true; M9 o) K, E- V, {& r
set my-row -1$ N! d' L" P: ~
set my-column -1
' s1 d7 l: C7 ~1 P% M' B+ | set my-phase -10 q3 _+ ~) y. v! D5 h+ o M
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets5 Q K) Z. n' j2 g5 n9 G1 y, H
set roads patches with1 Z" _5 _- Y5 H/ E) l g6 v4 Q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- [3 { I7 `. V% X (floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 z. }) S' P" ~; N1 r- ?
set intersections roads with
! F; |' j8 u8 O. J0 m( o6 n [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and+ E" a6 a5 R7 B
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
$ T9 C) I; W& V2 t v+ d 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?- g" j6 o" Y; r* u
set roads patches with& i7 w% {0 `0 O# V# n: R$ O
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" r O' |/ L1 L' \6 l! [% T8 g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]# ]) P$ D9 L- s! \, f: m1 e" c
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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