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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- T+ Q+ y( ^5 m; k
netlogo自带的social science--traffic grid这一例子当中,
' i# ?% M9 L' qglobals+ R& q, Y- i- d% N) ~( ~
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grid-x-inc ;; the amount of patches in between two roads in the x direction
) p7 e0 z8 j! E* { grid-y-inc ;; the amount of patches in between two roads in the y direction* J- u: G% R. ]4 h0 k! l' |
acceleration ;; the constant that controls how much a car speeds up or slows down by if
( a& k$ ?+ ^. Z, F: N) I7 |6 \/ U) a ;; it is to accelerate or decelerate
' B& W: G \$ J: } phase ;; keeps track of the phase6 x' {" v, F4 Q$ i$ b; F+ c+ ?
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure" {/ l+ E7 c% K6 }8 }+ D/ M
current-light ;; the currently selected light! P& U/ N/ p# |1 v& {2 o' o
7 S. h3 P: ]/ L; B ;; patch agentsets) a) ?: c9 P7 r/ P, s# {
intersections ;; agentset containing the patches that are intersections5 v' ?4 N4 `5 k7 ?4 c0 J$ e
roads ;; agentset containing the patches that are roads
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. \6 ~, P9 t( oturtles-own
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speed ;; the speed of the turtle
/ X9 v! @8 M$ O up-car? ;; true if the turtle moves downwards and false if it moves to the right
' y; |3 k2 @9 r" W wait-time ;; the amount of time since the last time a turtle has moved
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( C+ H) p( m2 Gpatches-own( d3 m' D- R3 I, \! H& X8 C$ u5 ^6 m
[
3 x( A$ s6 y1 _; D# F- R+ i& N intersection? ;; true if the patch is at the intersection of two roads
# ]/ ^" q. w; r D" F green-light-up? ;; true if the green light is above the intersection. otherwise, false.
; @5 w" L$ O, v: I* C ;; false for a non-intersection patches.7 X' e1 z0 A( v: N4 J
my-row ;; the row of the intersection counting from the upper left corner of the" M p ?: O! j6 A) G. G# e
;; world. -1 for non-intersection patches.
- i9 m5 l" b" K& @% R, x my-column ;; the column of the intersection counting from the upper left corner of the
8 p; y' D, d5 a0 J7 d9 r9 _ ;; world. -1 for non-intersection patches.; m- f. s3 T! }% H
my-phase ;; the phase for the intersection. -1 for non-intersection patches.. o- y, F, z+ `7 K
auto? ;; whether or not this intersection will switch automatically.8 G! ? Z5 y- m2 i6 @
;; false for non-intersection patches.! @& d, y: C4 Y( Z6 X
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! v+ n' P$ m/ u$ \;;;;;;;;;;;;;;;;;;;;;; q; w. @: q4 w/ ?$ ~
;; Setup Procedures ;;+ X; W, |; V$ W6 @9 T G; J0 O
;;;;;;;;;;;;;;;;;;;;;;/ ~+ q% I i) u0 ^
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;; Initialize the display by giving the global and patch variables initial values., d4 o* h' }. v3 m# n% Z
;; Create num-cars of turtles if there are enough road patches for one turtle to
, x. M' Q$ K3 T! V$ a6 G$ Q2 v;; be created per road patch. Set up the plots.3 \- A* v$ O" j8 D
to setup7 `! ]; Z2 p% B
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
: q9 ^# [5 q1 h* P- D) E: S. c4 u setup-patches
0 f5 n6 \% h/ p' |3 e& C: r make-current one-of intersections' r# v8 Z7 f0 j/ @ L0 B# |) c
label-current" ]+ T; P0 r, J# e% [
0 f( G6 u D5 B1 r8 H' P; Q set-default-shape turtles "car"4 Y+ `& c* [3 z- y$ M
( w1 g. p; P2 m+ S2 Y/ d& m v if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
$ a. E7 V' T- W( l1 z "road. Either increase the amount of roads "4 `, t8 e8 J0 e; t# Q5 E8 l. g8 A* b
"by increasing the GRID-SIZE-X or "
. W/ C5 |( j; _ "GRID-SIZE-Y sliders, or decrease the "# k n8 E2 J* d1 O5 x: S
"number of cars by lowering the NUMBER slider.\n"- V) q2 ~- l7 y( ~. }( a
"The setup has stopped.")
9 g/ s+ d: T, K4 n5 H stop% F! _2 ^6 Z" y. W+ _7 |9 Z6 g! W
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
6 \ K; ]2 z0 W* v crt num-cars- G: ~0 p J' T* R: }* Q
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setup-cars
, ~5 h+ _; m) ]0 o/ P' W( ] set-car-color
$ @$ k" Z# n) {* ~% @, T2 f record-data8 m; [1 f- m0 x2 o" b
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1 j% ]: o) {0 o X' `3 ?9 I ;; give the turtles an initial speed; Q! ]; `$ T% g7 Z9 D
ask turtles [ set-car-speed ]
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4 s) }4 x! L1 ^% m" {+ E5 d reset-ticks
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) D) i+ \% C% m& w$ h1 Q;; Initialize the global variables to appropriate values
! ~4 t3 H0 G2 w1 \to setup-globals' t I F" @+ ]$ ]* A4 h
set current-light nobody ;; just for now, since there are no lights yet* d9 X& T5 U* i# z
set phase 0
* r: ?, |& _9 U. D$ ^ C" \ set num-cars-stopped 0* R4 I) S- i" K8 w
set grid-x-inc world-width / grid-size-x( Z" J* t- Z" n& }
set grid-y-inc world-height / grid-size-y
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8 H9 t1 S: j i ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
0 f& X5 z* A0 G; F set acceleration 0.099' ]+ P' M3 |5 ?/ d
end
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) U1 x% h; Q6 G/ F;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
. E1 [- h3 U, S6 t) g;; and initialize the traffic lights to one setting* F' [ Z6 h. S
to setup-patches" V- Q1 m# b6 E& n
;; initialize the patch-owned variables and color the patches to a base-color# f1 ]7 Z* p+ b0 h7 e% _
ask patches
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9 O8 }0 E9 ^9 F& p set intersection? false! |( Q* ?3 u8 ~& S6 h0 _
set auto? false
" h1 r: ^+ V6 K D6 K1 ^5 v3 l set green-light-up? true7 s4 m# r+ a5 N2 }" G) S
set my-row -1
6 Y2 X3 ]2 w) T5 C: I set my-column -1: Y- i) @6 p% \) H
set my-phase -1+ H# ^3 ?% r4 r5 h
set pcolor brown + 3
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( ]8 R' Z. i3 ]) H# g ;; initialize the global variables that hold patch agentsets
6 h0 u2 B8 r+ D+ n u set roads patches with% q, F8 r6 D& c8 C3 ^3 `
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- J% D! x9 I& _. y% D9 k- ^
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ I" X# Q3 z- }
set intersections roads with
' b4 Z0 ^ Q- m2 S [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and+ ?- S, @. \0 p( _# w
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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; z6 L3 n. x; V8 M0 j ask roads [ set pcolor white ]8 o, G1 ~" J0 E* h% `0 P- U/ P
setup-intersections& D$ _; r1 A: G0 n( h8 \1 _. S
end
8 ?# ^/ V; P( Q! K ]其中定义道路的句子,如下所示,是什么意思啊?
+ J7 U. O. P5 R9 w J& [; w2 U# G0 S set roads patches with/ }# {' u8 r. r5 l) n. [) G
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; A! o) T# y8 ?
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 f8 N$ ^! 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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