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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。
N) w/ p0 ~5 Q, ~netlogo自带的social science--traffic grid这一例子当中,
3 |0 Z U" ]: T6 Z" ?- Y. [globals
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0 j, r3 M9 J& T& t' d4 ]1 _ grid-x-inc ;; the amount of patches in between two roads in the x direction7 W, m: X4 _ k
grid-y-inc ;; the amount of patches in between two roads in the y direction
% R7 j1 s& m9 k4 a8 { acceleration ;; the constant that controls how much a car speeds up or slows down by if
: ~& i% K6 a+ y7 L4 |' d ;; it is to accelerate or decelerate
0 W0 i& n$ H/ g8 L, I: D! [ phase ;; keeps track of the phase7 V0 J" r) ?/ @9 r1 D9 w$ a
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure1 Y/ u2 N0 ]$ |' i) [
current-light ;; the currently selected light
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;; patch agentsets
% Q' Y8 \1 U# [0 F" U intersections ;; agentset containing the patches that are intersections
' `, H7 S. @1 E- U roads ;; agentset containing the patches that are roads
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turtles-own4 \2 P# v- a0 A4 Y# k4 M
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speed ;; the speed of the turtle p$ `3 P7 E D0 H% O5 g. O
up-car? ;; true if the turtle moves downwards and false if it moves to the right
, L; u* Z3 g- j) O9 p6 x- S wait-time ;; the amount of time since the last time a turtle has moved
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" s8 j+ V# V, k. U$ |patches-own$ _% H3 O }% L" v7 I5 j: c
[
+ c$ B( r+ z+ m @( q intersection? ;; true if the patch is at the intersection of two roads
* C4 _ V8 b+ G green-light-up? ;; true if the green light is above the intersection. otherwise, false." n- V$ R7 { `1 b, D4 n% n- p. J% Z
;; false for a non-intersection patches.
; i, \+ g& @3 ]/ A4 j my-row ;; the row of the intersection counting from the upper left corner of the8 K/ V4 M% Z- p: d1 U* ]
;; world. -1 for non-intersection patches.+ s- f. }2 d* q% O2 @( o
my-column ;; the column of the intersection counting from the upper left corner of the
) I% N4 y0 o# h2 E/ T" k. J6 I+ H+ t ;; world. -1 for non-intersection patches.
. K& J6 {" ^6 `# C my-phase ;; the phase for the intersection. -1 for non-intersection patches., ~: q, L) f: v
auto? ;; whether or not this intersection will switch automatically. T: O4 A# z- [: `+ b3 a
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;* F7 o' d, M6 R& N1 o' A
;; Setup Procedures ;;
7 [/ q$ w% I& ~% d2 F;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
; X* B# {' S- R$ ]' ]) e;; Create num-cars of turtles if there are enough road patches for one turtle to$ y4 x- W: i' u; z6 M$ l4 Z) W
;; be created per road patch. Set up the plots.
; X6 F4 z& d% r5 r x& |8 g8 r) Uto setup
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. ]; {5 O }& X5 H5 F, Q setup-globals" b; ^4 s+ j% `8 V
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;; First we ask the patches to draw themselves and set up a few variables
5 K, d( B5 U3 {4 _8 l0 ] setup-patches
: _: r3 L6 m& _( Z- _4 e& E. \ make-current one-of intersections% Z) ^! R% ~! o4 Z% F
label-current- l) n0 L- _) F# _% ^! E: q
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set-default-shape turtles "car"7 [3 O, _ T2 ~6 h
. c: O8 I! a% x: h if (num-cars > count roads)# ~" I+ p# E: Q) ]
[
4 C( x+ [5 T2 t2 K$ I: j* `) y user-message (word "There are too many cars for the amount of "0 ?. X+ X. T1 P) \2 ?
"road. Either increase the amount of roads "3 q& o* V6 a% t) |! R% ]: j9 y
"by increasing the GRID-SIZE-X or "% n! A' H* N2 u0 I& Z) N
"GRID-SIZE-Y sliders, or decrease the "
/ Y+ b7 a3 [3 N1 j2 P/ _" Y "number of cars by lowering the NUMBER slider.\n", v: x5 ], p! @# W. R# m3 B
"The setup has stopped.")
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]
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
- u6 |( I" K( D9 z& v crt num-cars0 j) J. [8 I8 {. W v+ M
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setup-cars
3 Y0 R+ y1 ~! a set-car-color
B6 C5 ?/ h3 Y% t record-data
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8 ]; O# Q/ I' y2 N. r! ] ;; give the turtles an initial speed
' p' F& ^( P' g: P* x7 X8 Q* v ask turtles [ set-car-speed ]
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5 n% j0 }7 x' K; C$ U reset-ticks, u: ]% \% a# ]& l" P. P. a
end
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;; Initialize the global variables to appropriate values
- }, e) w1 m) q9 V7 y& B! ?+ qto setup-globals
) _: Q, P/ v# y% o1 g1 T, S6 J set current-light nobody ;; just for now, since there are no lights yet
5 ^ a% |: A5 J2 q set phase 0
4 S3 K6 f3 I1 R6 w set num-cars-stopped 03 H2 B) k, F' H/ f' J
set grid-x-inc world-width / grid-size-x6 [7 g4 x7 D( _6 ~7 u
set grid-y-inc world-height / grid-size-y
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% M! d( N% Q3 H& I8 r" v+ B+ @# f* e ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
2 D! o( R2 {) ]6 p6 Q. m set acceleration 0.099
# y; o, [. A2 X) O% H! N" Jend6 C: B! P( |/ W2 O8 u
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
; Y- f) d v0 ]8 V* Y+ V- i+ z;; and initialize the traffic lights to one setting1 g9 }- `& v8 |- {5 x
to setup-patches+ m2 w( D4 g6 G9 _; M7 C- J2 |
;; initialize the patch-owned variables and color the patches to a base-color- N B$ |. U3 G* Y% G" T
ask patches
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" I0 B' a/ g" h; r$ N set intersection? false
$ ]1 V5 M. Q0 b; E- E# g6 { set auto? false1 f x2 U; K1 ?/ x" z+ K+ k3 P
set green-light-up? true: S2 G, O2 ~3 f: S9 [ O
set my-row -19 w: v! N- g0 H9 i5 h5 S/ S
set my-column -17 g7 V! a3 B$ m3 h8 \
set my-phase -1
; K& M7 w7 y! ~: S* Z set pcolor brown + 3( K! t4 v! T- E M
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- R: E+ i2 J. _. ]$ f! R) d ;; initialize the global variables that hold patch agentsets9 s h. Z2 R9 W! F
set roads patches with' C) v7 H# x1 u4 y2 t
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- K8 o( Y, _7 }$ `' O9 F! {+ Y+ s (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
4 P; B3 w. S# g$ C$ ? set intersections roads with
9 u( v# Q& E. ~# F- I+ Q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
+ c$ ?$ [ @9 B1 @& _+ ^" h (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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( U5 E! d: \( Q+ Q: a5 {3 H ask roads [ set pcolor white ]. j) C7 X7 Y& M$ o2 V& y2 Q
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?
2 k( }8 `2 F$ `# C3 e7 j0 U4 m& ]! Q6 p set roads patches with
9 l s' B w$ n9 f; b. m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" p- q; f P, u2 t- r+ C
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 p1 A9 h0 K4 z. I7 g# a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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