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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。. t, w/ J) R+ y. ` H" P7 w
netlogo自带的social science--traffic grid这一例子当中,
' R/ O3 S& G8 I9 Xglobals8 j. W* C% P/ `
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grid-x-inc ;; the amount of patches in between two roads in the x direction
3 m, s" b+ X# ~+ _) L/ x# T grid-y-inc ;; the amount of patches in between two roads in the y direction! P! Z( y' F4 A( V8 b6 Q
acceleration ;; the constant that controls how much a car speeds up or slows down by if( Q# x6 t* M4 n! Q2 k
;; it is to accelerate or decelerate3 b0 |. d/ z* N# m" f7 T
phase ;; keeps track of the phase B% _; f1 k$ M' u" X* k$ f
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure& S7 a8 V5 E0 I( ]9 F/ W! t# d
current-light ;; the currently selected light
- b3 G( u) X& g |1 {# I' t! k ?/ T0 ~* }
;; patch agentsets! c; Z) W# d% Q
intersections ;; agentset containing the patches that are intersections' |+ S5 t& T9 w) H! D
roads ;; agentset containing the patches that are roads; d& D) K) i5 j
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turtles-own
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; g r6 A+ n' S& Z# A: Q1 v, Z, S$ `7 ?' ` speed ;; the speed of the turtle
9 H+ _6 |7 N* T ^/ [ up-car? ;; true if the turtle moves downwards and false if it moves to the right
9 u! x: m% X G7 m) v. D, x wait-time ;; the amount of time since the last time a turtle has moved3 ]( U1 r6 M6 W2 E6 I
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
! Q6 J2 B3 K+ O' W- ^ green-light-up? ;; true if the green light is above the intersection. otherwise, false.
3 F* [- o( @2 h9 a$ V: L5 l; Q( ^0 b ;; false for a non-intersection patches.
; E6 a; O3 g9 o/ e/ E1 O9 w) i5 K6 ? my-row ;; the row of the intersection counting from the upper left corner of the
- U" y) C6 \; R1 U) |( H) j( t* L ;; world. -1 for non-intersection patches.+ _" j2 v6 f6 V% y& l6 v, V
my-column ;; the column of the intersection counting from the upper left corner of the
, I2 h- f" k' \% x) A ;; world. -1 for non-intersection patches.
: `5 c, l- @1 ^* j8 I4 e( C my-phase ;; the phase for the intersection. -1 for non-intersection patches.2 S, N( @ r* @: T% L$ {
auto? ;; whether or not this intersection will switch automatically.
k& d, o5 e8 s/ Y7 |' N- F ;; false for non-intersection patches.
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r1 g5 c! K% H% g f- @;;;;;;;;;;;;;;;;;;;;;;
2 k0 k( { T- G3 a5 ]5 ], N;; Setup Procedures ;;" ~. Q2 j9 }# o9 K: D
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.: M# o1 z& A3 _
;; Create num-cars of turtles if there are enough road patches for one turtle to
2 a/ Y9 v. C. K! v" b7 k3 [;; be created per road patch. Set up the plots.9 J% B' H6 J* n+ O% q
to setup
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setup-globals, G7 |: G K; G& k4 [8 w
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;; First we ask the patches to draw themselves and set up a few variables- j0 n* e. c* v3 f
setup-patches7 W; `' {3 [, W" V7 l
make-current one-of intersections
3 l9 E5 m: }* S7 [# j" v3 ` label-current9 y8 ^3 i8 e- _, ?
6 x2 a9 D+ l7 z; m* l set-default-shape turtles "car"! V4 q9 n2 S @/ O% R3 G; p o- z
$ U G5 N6 `) `" _ if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "9 w* N5 B7 E8 g# ~' p) ^5 m
"road. Either increase the amount of roads "
$ g" h( j! l( O" l, X' [ "by increasing the GRID-SIZE-X or " I. k, C4 O& [$ `9 t
"GRID-SIZE-Y sliders, or decrease the "+ v0 p Z/ A$ y
"number of cars by lowering the NUMBER slider.\n"
9 r4 C! c" t+ e2 J& ~4 {( I "The setup has stopped.")7 U% c" ]& C: R) T% p; p
stop+ M5 p# m8 `6 u D+ u0 B$ }& J
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color- V5 O% o( [2 A9 P& L
crt num-cars) K6 I$ M) i6 N# `! @0 ]
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setup-cars4 t) @( ]6 P2 p% l* h+ `7 A
set-car-color0 |) r0 u7 z# T7 ]% l7 N
record-data2 f. n& Q* G2 I$ s6 B: }/ Q) R2 _
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2 q0 P/ r; L7 K6 j ;; give the turtles an initial speed; a4 z) F& E( [# k0 T/ H6 [
ask turtles [ set-car-speed ]6 {7 R; B. f- ~
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reset-ticks" p% k: H7 C; m( s: J( J
end
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, B' Z! m) B' [;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet; r& u- N; h' @; X% S
set phase 0+ ^- N( {7 w0 u% M+ }
set num-cars-stopped 04 t/ J& F) h. d
set grid-x-inc world-width / grid-size-x
8 v7 Y; ~) W1 j4 ` set grid-y-inc world-height / grid-size-y3 A/ b( o0 |; o. o J! w
. j9 ~7 z' I1 t: u ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary: v8 {: q7 R3 i" z- [+ D3 i
set acceleration 0.099& X) J# k) M9 ?; O1 c e T
end3 B; Q- R$ x* e+ S: J; T* ?$ N, i
j( ?; h$ t, U( Q;; Make the patches have appropriate colors, set up the roads and intersections agentsets,7 `# Z. e7 t, f! E
;; and initialize the traffic lights to one setting
! V' U' u' J) D& y. j8 Ato setup-patches
$ G, B5 n7 R) ~ ;; initialize the patch-owned variables and color the patches to a base-color; n+ r0 j3 ?6 M2 ]$ G7 ?: D$ d
ask patches7 H: }3 I/ M- a: \, B" b$ }0 {4 [
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: E6 [, V+ \2 w( T* P3 I& l set intersection? false
: |" Z5 A3 x- \$ u4 e set auto? false& \2 w+ D4 f; \( n8 _
set green-light-up? true
3 r8 y2 ?) d' C. l( c4 e+ K5 e set my-row -12 s! E) J8 O7 i
set my-column -13 p( s1 F) E) q2 e. b' i( V
set my-phase -1
$ F0 L& c" n5 R0 F* V( c set pcolor brown + 3. {6 A& v0 D1 o6 R5 ?
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;; initialize the global variables that hold patch agentsets
3 ]5 e4 [! T) C# e( W# q7 @5 G set roads patches with
! ]% A/ A( ~* q9 ?) d [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 G6 i% Z4 P) K4 w8 J5 Q, Z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 g2 g. M8 D$ D$ E4 }( O
set intersections roads with
" i% v3 g# s6 Y0 I) H. r, H* \5 K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and2 G# g$ w% t8 U/ }) h1 q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
+ _2 x9 h( A6 f- M2 h setup-intersections
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1 ?! |$ b4 o8 |& K2 ?' Y2 ?- B! b" A其中定义道路的句子,如下所示,是什么意思啊?" T- R# s `4 r
set roads patches with
& g9 I, r0 G* t0 K1 X5 {& r0 w [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: q6 H6 h- j% V4 c (floor((pycor + max-pycor) mod grid-y-inc) = 0)]" L/ M d# A9 q6 m$ R' r
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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