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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; P g7 k, X1 T4 l8 g/ i
netlogo自带的social science--traffic grid这一例子当中,
) \( E" _) Q) g2 k& t) W. vglobals
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1 p# \ r% D5 p5 M; u grid-x-inc ;; the amount of patches in between two roads in the x direction! H$ C9 L3 r d
grid-y-inc ;; the amount of patches in between two roads in the y direction) X1 s$ V" U, S
acceleration ;; the constant that controls how much a car speeds up or slows down by if8 l1 d: b* i9 g0 I6 e
;; it is to accelerate or decelerate+ G+ S, [5 p6 d1 `
phase ;; keeps track of the phase5 \5 | N3 |/ R9 @/ C& a
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure0 {2 \+ R% I( |" t3 [8 r
current-light ;; the currently selected light& D$ J5 i. E: [' c
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;; patch agentsets6 g9 P- k/ z) y" o5 I
intersections ;; agentset containing the patches that are intersections
# h* @7 d6 X* R) |8 J5 a1 k roads ;; agentset containing the patches that are roads
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turtles-own- p9 d7 y) ~; p* `7 A
[
& j6 @- f, H& Z: M3 F3 X* \ L speed ;; the speed of the turtle# K' C0 G& t! d0 o6 p
up-car? ;; true if the turtle moves downwards and false if it moves to the right
1 q" v4 G9 b7 Q. w, i: L wait-time ;; the amount of time since the last time a turtle has moved
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patches-own8 Y, j7 o( P$ u" c: ^
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intersection? ;; true if the patch is at the intersection of two roads
% | \3 O% C3 T; P& E green-light-up? ;; true if the green light is above the intersection. otherwise, false./ }) \$ R4 D% R5 P
;; false for a non-intersection patches.% s' D1 F W" @+ D' D0 L& ]
my-row ;; the row of the intersection counting from the upper left corner of the
7 G6 i$ c8 m1 C. W ;; world. -1 for non-intersection patches.( h8 S& L) ^0 N! [: b, S6 _" [3 ]5 p
my-column ;; the column of the intersection counting from the upper left corner of the
! ~9 T4 s+ W2 c* K ;; world. -1 for non-intersection patches.
% r" r5 R8 A: k; ?: v6 O my-phase ;; the phase for the intersection. -1 for non-intersection patches.
/ E" d: I: m3 D1 l" b auto? ;; whether or not this intersection will switch automatically.
* A# b% E: M1 v- s9 I6 a ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;$ U& l% |4 [" ~" s
;; Setup Procedures ;;
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1 H- }' g9 x8 S) d: a;; Initialize the display by giving the global and patch variables initial values.
$ r& ]/ @: _4 c N;; Create num-cars of turtles if there are enough road patches for one turtle to
2 v9 n. ~- C+ k5 k& V7 E' u;; be created per road patch. Set up the plots.
1 K& ]& c5 [9 ?/ Jto setup
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setup-globals" \, \9 r6 S5 t
4 c4 Q3 f* C1 a& c A! ? ;; First we ask the patches to draw themselves and set up a few variables
! _& o+ f s. ~9 n setup-patches# f( n; \) u9 c
make-current one-of intersections; k/ m6 p! w5 H* O% Y5 D8 C
label-current; c. t8 p4 [# R) a3 J
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set-default-shape turtles "car"
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if (num-cars > count roads)
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j2 Z: Z6 y& p$ N user-message (word "There are too many cars for the amount of "
: X E9 z% y8 K# O. k3 D; R "road. Either increase the amount of roads "
* ^# V( {4 j: I T! q* i4 t "by increasing the GRID-SIZE-X or "% \; _6 m* |$ @2 M, {- H Z
"GRID-SIZE-Y sliders, or decrease the "0 I1 U' y2 ^6 T* _2 o& H( j3 U
"number of cars by lowering the NUMBER slider.\n"
& J3 \, h; a8 X, ~! a8 A* z "The setup has stopped.")
& h/ \4 ?* t$ a; U- t# i. d( o stop
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' o, x8 A4 }$ F ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
) ^# ~0 A: j( d1 q- Q' z. e; D crt num-cars
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t+ O @1 {5 [) P setup-cars; H; a/ [. j y& C8 i: E& }
set-car-color
L5 v* i2 `5 J: L record-data7 X8 e% v& \4 B- L
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;; give the turtles an initial speed* S6 M6 h4 M* I
ask turtles [ set-car-speed ]
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reset-ticks
# W, \: d3 b* Iend
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: V4 J7 K! l! i4 I1 E# r/ q;; Initialize the global variables to appropriate values
" ?1 e- z% D& J+ Ato setup-globals
0 f$ Q/ ~; y( s1 \$ I9 p set current-light nobody ;; just for now, since there are no lights yet S8 Z$ J. V( a! s
set phase 0" o" t3 h, f" A% @: f
set num-cars-stopped 07 w0 D- U0 L5 r7 P7 v" b& P; G
set grid-x-inc world-width / grid-size-x
( C) P% c6 P/ v! O( o1 A% _7 | set grid-y-inc world-height / grid-size-y2 Z- A z9 D& g2 ^2 T+ j A
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
" N' b/ ~/ \! s7 z- T set acceleration 0.0993 r" T3 E! n0 i s7 Z5 S
end" {# f7 x9 ?, C1 F2 C
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
) F2 Z& x$ P) U;; and initialize the traffic lights to one setting- _) w9 ^1 q3 @
to setup-patches
9 g: f+ |% R7 B- f# h ;; initialize the patch-owned variables and color the patches to a base-color
8 K. u* I" B: V1 u+ M. m: A5 `$ r ask patches, B8 {) c+ h# N2 [
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set intersection? false
P& ~- k- P: x- }/ x0 g3 N" P set auto? false
# H# D, w' \6 S set green-light-up? true
) g5 |0 z1 C* f( n0 C5 i/ K set my-row -1
/ x( D9 k: F& N2 R3 S set my-column -1
. [ f. w" r# _# [% ?6 @ set my-phase -1
; c7 N0 h7 ?$ y6 v' K set pcolor brown + 3( Q ?- i2 O+ F( D& L5 ~/ r
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9 u7 M6 C' `) i0 f ;; initialize the global variables that hold patch agentsets
6 o& ?& M V" |' d' X set roads patches with2 o4 r0 ?8 u. L3 M
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; s, `3 i1 B% K" t3 _6 c
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 Z& C- d0 p7 {1 S( f, U* N7 x9 f1 x set intersections roads with
) V: j2 K. J# G( x [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
3 B4 K+ O9 t1 o/ H/ R: ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]% D5 V$ d3 E2 O* n
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ask roads [ set pcolor white ]" l! Z j1 P& X! O
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?" [4 v/ u3 x1 C- r& r
set roads patches with( A! Q6 a1 A) Q) }, n6 G$ r
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 b; R: U9 a$ r1 L6 Q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# p8 \4 B) A6 b( }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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