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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。8 P6 P, Q5 `! P2 o/ r3 f V7 X
netlogo自带的social science--traffic grid这一例子当中,8 _1 M. k) d7 ?/ D3 I, Z
globals" [: V7 U/ F D' Z# |/ |
[
6 ? U% I E' } grid-x-inc ;; the amount of patches in between two roads in the x direction/ S* U2 A9 x( s( O& u
grid-y-inc ;; the amount of patches in between two roads in the y direction
# c* e' K$ ]1 j& z% V3 d6 k acceleration ;; the constant that controls how much a car speeds up or slows down by if5 g* M7 p- n' j: K3 P+ ~+ t
;; it is to accelerate or decelerate
1 J$ g- c% I, V1 X$ Q4 F Z phase ;; keeps track of the phase, |2 I8 n+ b5 t3 m l
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
. d, d9 \4 w, M7 {- J7 J+ `1 g) { current-light ;; the currently selected light2 N0 k& z, a! z" E! {9 N( b& K
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;; patch agentsets" M O9 _; _* k' X
intersections ;; agentset containing the patches that are intersections d" |! K9 K, ^* o2 h
roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle0 X! o% B; A: \: c% ]( {
up-car? ;; true if the turtle moves downwards and false if it moves to the right
- @8 ^0 n) O7 O: C) y5 ~ L7 | wait-time ;; the amount of time since the last time a turtle has moved% y5 E4 F3 O. w' \+ K1 ?
]
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patches-own1 [: p' ~8 v4 H: l
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intersection? ;; true if the patch is at the intersection of two roads9 U ^, |* ~8 s# ]" ^
green-light-up? ;; true if the green light is above the intersection. otherwise, false." m' L5 R" I, d! l& i' j
;; false for a non-intersection patches.
+ p1 F- b& Z& D my-row ;; the row of the intersection counting from the upper left corner of the
3 Z4 q# T6 `0 w ;; world. -1 for non-intersection patches.7 O0 h: M3 J: Q7 _# \3 T+ j. J; L
my-column ;; the column of the intersection counting from the upper left corner of the" q$ L% H6 G8 n& L2 w
;; world. -1 for non-intersection patches.
/ t9 M- |" u* \, h) E( U my-phase ;; the phase for the intersection. -1 for non-intersection patches.
1 `$ i0 w( ~; x/ Z auto? ;; whether or not this intersection will switch automatically.; a; I f. C' V
;; false for non-intersection patches.8 a" I$ x# }! |$ e. `, i2 D
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. A7 U( N& ^, T3 X;;;;;;;;;;;;;;;;;;;;;;
: c+ m! E$ H1 K$ t3 Z;; Setup Procedures ;;/ l% d0 I# h! q/ ]: c6 [5 C
;;;;;;;;;;;;;;;;;;;;;;
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7 o! C" c$ I# ^/ O; B/ I4 M8 O;; Initialize the display by giving the global and patch variables initial values.. ^# k, W- ~/ p- W) a5 G' R& I
;; Create num-cars of turtles if there are enough road patches for one turtle to
) N7 F8 g9 @' y2 u;; be created per road patch. Set up the plots.
2 k; b" ?) U8 d9 u eto setup" I! z/ `2 t: ~& ]4 |6 r% y
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setup-globals
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0 R& S! s; Q6 }3 E9 R ;; First we ask the patches to draw themselves and set up a few variables' `5 \, w6 I3 V) q$ d* c& Z
setup-patches4 O* }1 Y# w( L" j$ Q0 T" p2 i' k6 c% |
make-current one-of intersections# o# _" S( u4 e1 o1 t1 r9 x' l9 P
label-current
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set-default-shape turtles "car"9 ]% M- | K6 r2 s
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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 "5 s6 {/ ?7 o% ]
"road. Either increase the amount of roads "
/ l; n# ` ^" O6 q2 ^2 N# Z "by increasing the GRID-SIZE-X or "
6 _: }. `. x+ y! O. [1 m "GRID-SIZE-Y sliders, or decrease the "
. z* J5 q/ Y2 q7 T( V) R& v: { "number of cars by lowering the NUMBER slider.\n"" R2 i7 B s" F
"The setup has stopped.")
3 J, ?4 l7 C5 |6 N; c stop- |7 S# x3 {8 A
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
5 C; B5 Y0 n. B) \4 s crt num-cars
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setup-cars% x! x5 }- Q: L* N4 w r7 Y) ^
set-car-color
% w8 _' M. _4 s6 X, P, p# Q' T record-data, [& y) D$ e; [
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;; give the turtles an initial speed
) n0 |% h5 |4 X$ ^& [. Q ask turtles [ set-car-speed ]
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0 O0 P; a" h n/ Y V reset-ticks
* L4 Z3 I5 b' t4 E( }9 \" [' }end
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/ W1 n+ G4 S* z9 _- G1 W* `6 B;; Initialize the global variables to appropriate values
7 A' f x: E' w9 v# V& `# Wto setup-globals7 G9 W r8 s! p: Z5 p" I5 ]
set current-light nobody ;; just for now, since there are no lights yet
0 S8 e* K' M' p0 b$ |" M9 z3 z1 S set phase 03 U7 L2 Y9 T& H! R. _# v
set num-cars-stopped 0
4 @4 V# b# |! S& u& d8 U5 a6 @ set grid-x-inc world-width / grid-size-x
8 r, p" K( Y. [0 ]# r, t set grid-y-inc world-height / grid-size-y5 Q s6 Y% T" r _( q% p- i. \
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
0 C. A- A; O, }3 T set acceleration 0.099
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% Y& b9 b- [8 ~3 l _;; Make the patches have appropriate colors, set up the roads and intersections agentsets,3 @/ ^) q) K4 b( a
;; and initialize the traffic lights to one setting7 g3 X; j0 L7 @) a9 {4 C$ f- G
to setup-patches% l( \5 r& g; ^ ] i
;; initialize the patch-owned variables and color the patches to a base-color
2 S2 x4 g: M5 F/ P! |1 ] ask patches
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1 Z! o3 y2 r$ V: b* H set intersection? false. p8 p& f( O# y( N/ G6 R8 S
set auto? false8 @4 n& M4 ]- X5 r: k
set green-light-up? true( f/ u' L- f A$ _9 M( t* a
set my-row -1% a" p5 I. b/ J
set my-column -1
0 @+ B+ ]. n. R& S set my-phase -1
* @: X# F8 b+ f0 | set pcolor brown + 3
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5 ?$ Y: b9 d9 X4 A& J ;; initialize the global variables that hold patch agentsets
# F! U1 H# G, J! p2 ]8 f3 e set roads patches with
- [4 o8 R a8 E6 |4 g) X' n3 G4 ?- J [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# b/ `- J# N% d& F' R: ^& k# }3 T
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
R1 i2 M0 _1 k) u) u. `0 y set intersections roads with
+ V8 a4 h `8 k1 i9 W [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and2 F4 U( e2 a! u! ~ b2 |- h
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]: m0 k" Z( L8 Q+ p1 p4 s
' W/ b, n( h' M/ ^: E3 R+ w0 f ask roads [ set pcolor white ]
4 Y$ ~8 j9 s& Z' @/ P& \/ P setup-intersections9 i& A0 a+ F/ M% e3 c- o3 v1 h( r9 X
end
. p% v* u( v/ T6 [# N) L其中定义道路的句子,如下所示,是什么意思啊?1 {' C& Q. U2 p5 S) j/ F0 w
set roads patches with- K+ G8 c7 k' i8 i! M
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 D! u5 h# |6 q) C2 A- R (floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 p! ? }% i$ ?& v) m0 D# K
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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