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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。: H1 Y+ E5 ?7 K$ i0 S2 s
netlogo自带的social science--traffic grid这一例子当中,
6 T: U. s0 h) D9 cglobals! j4 P& {9 u' b k; [9 V. n
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; @' N2 v! E! ^/ x2 h& k) Q5 T grid-x-inc ;; the amount of patches in between two roads in the x direction
8 {6 S+ ^7 z6 w; A1 a7 t grid-y-inc ;; the amount of patches in between two roads in the y direction
$ M7 a$ r5 V2 K! w" t) \& R acceleration ;; the constant that controls how much a car speeds up or slows down by if% ^; q/ Z* S# n
;; it is to accelerate or decelerate0 ~) y! d8 a _' g5 C3 @) D
phase ;; keeps track of the phase: @ k4 R0 W8 e9 i; i" _/ j
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure e* G& `1 O+ w2 d% l, S
current-light ;; the currently selected light" U( v1 }, e/ [" n+ s4 F
* U Q3 @" K$ _: G; j- n ;; patch agentsets3 L% J0 l# n7 @& @7 ~$ J; Z
intersections ;; agentset containing the patches that are intersections G E4 G/ v* }
roads ;; agentset containing the patches that are roads
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) R3 c' d% `8 H3 Z5 q: Uturtles-own2 J4 j7 L' v6 s6 r! H- l% K- C
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speed ;; the speed of the turtle0 j% j) @ ]4 U7 G4 |# I/ y1 r
up-car? ;; true if the turtle moves downwards and false if it moves to the right: @, D: \# I 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
# r' u6 y. }$ V* V1 M+ ?7 c green-light-up? ;; true if the green light is above the intersection. otherwise, false.
+ g$ {" k" \" o2 q ;; false for a non-intersection patches.
3 i& g8 _# K: n# o- j- r my-row ;; the row of the intersection counting from the upper left corner of the" a" J" ?2 Y8 ^* u, |
;; world. -1 for non-intersection patches.
& }6 K2 c2 w& u) t- {0 Y my-column ;; the column of the intersection counting from the upper left corner of the: b' {8 K2 D# m" ]
;; world. -1 for non-intersection patches.
1 y/ b) Y; U3 r# v my-phase ;; the phase for the intersection. -1 for non-intersection patches.
5 g% g2 p% T5 y! v$ W auto? ;; whether or not this intersection will switch automatically.5 t3 Q4 X% {) K* T. K, _7 Y
;; false for non-intersection patches.6 Z& D4 r9 ]2 S0 } ~% S! e2 m& n
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;;;;;;;;;;;;;;;;;;;;;;
6 E7 f1 p/ ^: m6 ]: z: E: _+ u;; Setup Procedures ;;
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1 W _. D: p8 O1 [$ e0 U. X1 F$ N2 o;; Initialize the display by giving the global and patch variables initial values. T; O0 {; d+ }. y; E
;; Create num-cars of turtles if there are enough road patches for one turtle to# C0 o; a2 u+ n$ w. b, y* C {. }" l! m) F
;; be created per road patch. Set up the plots.
* r! @$ L6 p" p u. F# T8 S3 W. [to setup% L7 h3 w9 }. x/ u# O3 q/ N q
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& D; w! F' p( l/ S! K setup-globals( V y' Q) i! ^/ A8 Y1 C
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;; First we ask the patches to draw themselves and set up a few variables+ `6 L- F2 g# |1 o. Z8 u& }$ u1 s
setup-patches0 w9 a2 v* c6 z8 E: P
make-current one-of intersections
2 c$ |- y. K* D! {# z2 T label-current
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set-default-shape turtles "car"6 n. @8 y" |8 D% ?) x( _/ {
% b4 f G2 l) M4 q5 r7 w, @ if (num-cars > count roads)
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3 z4 b! }3 ^/ d- i, A( Y user-message (word "There are too many cars for the amount of "# A8 {6 s( v6 w2 V/ ^+ N
"road. Either increase the amount of roads "7 e, M9 [3 @! q H& E
"by increasing the GRID-SIZE-X or "% a% `% u. _* t0 ?- h
"GRID-SIZE-Y sliders, or decrease the "
$ e- O& F& R* c. [! u- @8 l2 U "number of cars by lowering the NUMBER slider.\n"8 b( f) Q3 O& ~2 O: P- N; V) o
"The setup has stopped.")( {3 \ X5 z) a( c4 G2 U$ w9 F( H
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color3 ^7 N; @5 E: B. r9 Q8 Y" w
crt num-cars
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7 t3 g# m' }1 F( ?6 x setup-cars* ^/ u0 S4 d7 g* L' q: G
set-car-color7 ?( R/ V8 b$ d- M- ]4 Y
record-data
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;; give the turtles an initial speed: F3 g& }, T% a; R+ N
ask turtles [ set-car-speed ]
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reset-ticks
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;; Initialize the global variables to appropriate values. m4 t& D! I9 C
to setup-globals; k: Y& |7 N9 G9 R6 r& l" z+ s* N" C2 T Y
set current-light nobody ;; just for now, since there are no lights yet1 @ y2 X. I4 T% [ i/ W& R6 S w% U! {
set phase 0
+ A! O2 `# r/ G. t' x' U set num-cars-stopped 0+ Z3 p3 {' b8 q
set grid-x-inc world-width / grid-size-x
/ k v1 @ h5 N0 g8 C* o set grid-y-inc world-height / grid-size-y* S% H9 j6 i, v5 \1 c! T! N$ Q3 u
n# v* B! G" ? x, {8 M ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary' C& A3 X" M7 x9 u, s6 o
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,0 ^5 _% Y+ L& F3 W; Z/ x
;; and initialize the traffic lights to one setting$ K2 S) w' }/ e
to setup-patches
( ` P, b) o- d8 Q8 b ;; initialize the patch-owned variables and color the patches to a base-color
+ b, x! \3 X3 f/ U; K+ X ask patches
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9 z) T! s/ Q( N" q' E0 K6 R set intersection? false
9 [" ~& {0 r' Q' | H) C set auto? false
0 j4 i2 H. Z! _! M set green-light-up? true
8 ~5 A% Z; b5 E0 ? set my-row -1
6 e+ K. k& S% q set my-column -1- Z T$ r7 k$ |
set my-phase -11 P- T1 z1 t$ S$ e$ k5 U- }
set pcolor brown + 3
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N `0 D8 `( c% t/ p$ n, z, Y M ;; initialize the global variables that hold patch agentsets
% ^# l/ ? w" \: l2 q: D$ Z set roads patches with7 W# U/ C( `7 [& n+ s/ o0 z0 ]
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# \( f) Z; ?- }$ h (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 J( N. ~; E' m& ~( |; A- C set intersections roads with1 ~9 ]. s3 w6 ~ d1 q+ `9 N0 u
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
" K: k8 W: }' O0 X0 E- G (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
5 [7 [- p! E6 n0 m Z1 [ setup-intersections, g7 `+ v* P, b, w. {( C" G) Y
end
$ p. Y3 U1 O) ^% e$ P/ k其中定义道路的句子,如下所示,是什么意思啊?* x3 ]7 v4 G' c0 B
set roads patches with# f, `! p- a3 P" N A' B
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" W1 D7 ~$ C* h ]+ }- v% { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# \9 g, {- q, ]9 {9 N9 f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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