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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。, x J. r: B: m5 h7 v- i
netlogo自带的social science--traffic grid这一例子当中,
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[
; I- F3 y) J( [ I grid-x-inc ;; the amount of patches in between two roads in the x direction7 S4 w, I) }( r D& N
grid-y-inc ;; the amount of patches in between two roads in the y direction$ h# {' z% H6 M
acceleration ;; the constant that controls how much a car speeds up or slows down by if
! _2 ?9 p% z m9 h8 D- b! |: S ;; it is to accelerate or decelerate# O9 d5 J, U: R0 J7 a
phase ;; keeps track of the phase
4 K& w9 J9 m- N" t6 b num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure0 j1 K/ M+ h" M [$ J
current-light ;; the currently selected light. }" d& F. b$ N$ |7 U/ k
: n3 o& q- b: X' O7 t8 G ;; patch agentsets7 z* |( _' N' | V4 C9 }( Z
intersections ;; agentset containing the patches that are intersections
6 @8 j3 W, x1 l3 ^3 M# h$ h( s roads ;; agentset containing the patches that are roads
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3 Y- \4 o" a; w" {4 s7 m' nturtles-own# U7 L, |$ \2 k9 ?
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speed ;; the speed of the turtle, d3 `" U; W2 [2 }; r2 L
up-car? ;; true if the turtle moves downwards and false if it moves to the right
: h- s+ b. }+ U wait-time ;; the amount of time since the last time a turtle has moved
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9 a# H7 V4 W/ b2 M: n! G& s3 m8 L+ Apatches-own) f- r5 C1 h* ^6 G0 x: }4 t6 R
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2 y0 j' N5 O# |6 k, T intersection? ;; true if the patch is at the intersection of two roads
& L- {1 G; _% H& Q% h4 } green-light-up? ;; true if the green light is above the intersection. otherwise, false.0 }' k1 i- b7 h5 j: o- a
;; false for a non-intersection patches.4 Q; f1 z$ S: o
my-row ;; the row of the intersection counting from the upper left corner of the S& }1 I3 F1 o% R. A" i
;; world. -1 for non-intersection patches.. h8 v. a4 O4 l0 i: A2 c" W: N! d
my-column ;; the column of the intersection counting from the upper left corner of the; m- E8 b0 u+ B N9 r
;; world. -1 for non-intersection patches.: q. v6 l8 X5 k, m7 @$ o
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
( t* |" x$ R9 Q auto? ;; whether or not this intersection will switch automatically.3 I, L. R, S+ a) u
;; false for non-intersection patches.5 N- k/ J* p0 k% J. z! z8 D$ u
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;;;;;;;;;;;;;;;;;;;;;;
& L' m0 [& P3 ?$ @* b;; Setup Procedures ;;$ z6 F( {1 B. }2 A' n- [+ W
;;;;;;;;;;;;;;;;;;;;;;
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: u0 n2 [$ O7 D0 M) i;; Initialize the display by giving the global and patch variables initial values.
% \) S/ {# n( w S: @3 q;; Create num-cars of turtles if there are enough road patches for one turtle to
. q3 O8 D: [& N# a0 J;; be created per road patch. Set up the plots.- t! X' o7 D3 j. m6 @9 f3 m: i
to setup
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setup-globals
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/ t7 t0 [8 _9 l* D ;; First we ask the patches to draw themselves and set up a few variables
0 f7 `" I2 {/ e. h; z7 s- Q setup-patches
$ L. P0 C/ O4 }! J9 O# ~* p0 O( y make-current one-of intersections
: ?# a4 K" }; b 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 "
0 @$ u6 i, m+ _( |* ? "road. Either increase the amount of roads "
/ t V. d" A0 H. ]' s; [ "by increasing the GRID-SIZE-X or "
; |8 T$ M: U3 g- j+ \6 V "GRID-SIZE-Y sliders, or decrease the "
* b1 {# V$ M, H "number of cars by lowering the NUMBER slider.\n". N& |, U0 J) p3 X5 r$ R% ~
"The setup has stopped.")# Y, s' l7 G/ A8 a8 m/ T
stop2 j. e4 H4 |" [1 b }, B
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
* f) J# M) M' `& G/ q5 L+ [ crt num-cars
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setup-cars
$ @: s6 R6 P' `( b4 v6 G8 U* H% L set-car-color- x0 j: f- ]" }# `) X2 T+ {
record-data
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;; give the turtles an initial speed
1 {7 g* N- W; e! M& W3 i ask turtles [ set-car-speed ]( j8 v4 x6 V8 t5 j9 N& W! M+ m
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reset-ticks# f8 y' `- j/ s% O0 O
end1 w' I1 `4 K2 ~$ }
5 O; `- o# w/ z% Z8 S( S;; Initialize the global variables to appropriate values& H6 S8 F+ J0 m, n0 z
to setup-globals Z( w! |2 O0 x0 ]
set current-light nobody ;; just for now, since there are no lights yet
7 U- e v6 T& q+ J6 X% P set phase 0
9 a w, L* @ k, H9 ~3 k+ S set num-cars-stopped 0
! @6 G0 M2 ?8 Y- B7 ] set grid-x-inc world-width / grid-size-x! U. h9 o7 y% ^( q
set grid-y-inc world-height / grid-size-y* g+ {8 O' T- A6 n, b
$ \5 _: r5 v6 i+ S- ?, S* K ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary9 E2 F' G& q+ W# l4 `% g( G
set acceleration 0.099; |# o M+ z' W2 N+ s4 f' D4 E
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 J9 ~0 v* ~* H
;; and initialize the traffic lights to one setting' t. j+ b( I Q9 [0 {8 y
to setup-patches, x( p3 f$ Q- ]: _+ D- q
;; initialize the patch-owned variables and color the patches to a base-color, ~5 N0 f5 D, ~+ ^# q6 W( ]2 T, ^4 U
ask patches
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& Q$ `$ J. F4 U2 o set intersection? false2 V: ^) h# a! a7 x6 d
set auto? false
9 A( q9 _$ F% \4 @$ N" Q% Y set green-light-up? true
/ _$ p0 `" T6 Y" I set my-row -1
; p' a/ {0 s8 v3 F; b# v% ^ set my-column -1
* j: }& O* x1 W6 O# M g9 h2 B set my-phase -1' M- g, \: V `% C. D- O" ?: i: r
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
2 l$ r2 o {" G. V set roads patches with5 m8 m' j' P, u. s
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ \: j: o {7 L* I! w0 ~1 w! \5 t8 d
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]& U1 \! M' M; {- [! V
set intersections roads with
) W& t1 v2 C7 ]6 \% U: N [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
; a# P% L8 {3 K2 {1 n& x1 p (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: ]1 x a6 B' a0 P6 x$ f
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ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?" v/ ~6 I0 C p
set roads patches with
# g% e/ W3 m0 K8 E [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) r* b2 G8 I. u- ^3 W
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]% V) c- H. K2 `+ z! z& h- z
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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