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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。' L) L$ r. l6 b% e, ?; A
netlogo自带的social science--traffic grid这一例子当中,/ j9 [, T* @: j4 o/ h) i
globals ?: c9 r! g8 n
[
3 s7 T! N Y, ]! j' _" V grid-x-inc ;; the amount of patches in between two roads in the x direction" |" A% ?9 W: O; c* l/ z6 K
grid-y-inc ;; the amount of patches in between two roads in the y direction E* H8 U T0 b
acceleration ;; the constant that controls how much a car speeds up or slows down by if: {* K( u* s) _$ A0 U2 b+ o
;; it is to accelerate or decelerate
2 L) _( Q7 w& \" R* A+ o phase ;; keeps track of the phase+ T6 L/ \2 S; @
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
' M z: @3 v" r3 n+ |( I current-light ;; the currently selected light
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! ?( [) Z: j: X5 t S ;; patch agentsets
/ e/ N5 K' a5 H# v+ G8 g intersections ;; agentset containing the patches that are intersections
+ d: E- c0 G' o5 K( O) O# G roads ;; agentset containing the patches that are roads0 m& O5 `4 a* v! W) U) J4 t
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turtles-own
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speed ;; the speed of the turtle
! @* f5 \% Y/ s up-car? ;; true if the turtle moves downwards and false if it moves to the right3 N: v7 i) x, y1 l2 W* F
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads" B4 }: L# X' V6 k1 @: s6 s* a
green-light-up? ;; true if the green light is above the intersection. otherwise, false./ w2 x# C$ _4 e* Q1 ?! Y4 V
;; false for a non-intersection patches.8 v& \& y4 u, E/ T) v5 u( G+ S( c
my-row ;; the row of the intersection counting from the upper left corner of the
- u7 ?& y4 }! t* V9 J% F ;; world. -1 for non-intersection patches.: F2 |/ i$ L2 ?0 t
my-column ;; the column of the intersection counting from the upper left corner of the
& H& c& P q# s: I" `/ f& J% P ;; world. -1 for non-intersection patches.1 z0 k3 O* X7 Y, F, u6 w8 C* J8 P
my-phase ;; the phase for the intersection. -1 for non-intersection patches.) P& ?) g) A2 S8 l$ z2 X1 Q
auto? ;; whether or not this intersection will switch automatically.1 R5 O2 ~0 c$ p$ V/ W" v. c, n
;; false for non-intersection patches.5 F& E$ e7 M0 f# m8 p: k. m
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7 F( I6 k, f- v6 s;;;;;;;;;;;;;;;;;;;;;;
: G. X4 |! \4 b; k7 a2 a;; Setup Procedures ;;
+ }: x$ e6 ]! D;;;;;;;;;;;;;;;;;;;;;;- I+ P M L4 B5 R& g, A t! A
& ]( n' g0 W0 n4 z3 z0 i- S;; Initialize the display by giving the global and patch variables initial values.
/ [4 S# f% y2 f9 }9 Q2 j# n$ u' K( v;; Create num-cars of turtles if there are enough road patches for one turtle to1 u- s- D7 E5 K! C8 K% k' M; q
;; be created per road patch. Set up the plots.
( \; Q# @! ^* d$ lto setup
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* d1 S. W! t, k/ b setup-globals
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8 L2 o b8 W9 {! p' h* [" R, s ;; First we ask the patches to draw themselves and set up a few variables- f3 h! c5 a/ l& ?' M' a) \
setup-patches. r; i. O. ]( m- p9 M
make-current one-of intersections/ Y$ n8 ^. ?" |3 h
label-current
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set-default-shape turtles "car"5 k W {2 f5 I
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if (num-cars > count roads)
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8 }' f1 J6 ?+ b1 j4 O& W user-message (word "There are too many cars for the amount of "
& B. r f l+ ^( _# H. Q+ |9 ] "road. Either increase the amount of roads "2 D' D5 P& X- U- v; {( q7 h
"by increasing the GRID-SIZE-X or "! c$ W4 p/ b' a9 X3 F O) l+ T
"GRID-SIZE-Y sliders, or decrease the "
) P* o! m$ S) O- Y6 h3 b$ F "number of cars by lowering the NUMBER slider.\n". V! P; a& V2 h2 |
"The setup has stopped.")
, C% F! K1 R8 T stop( {! I9 w, O" Z' h# S
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
, D! I, ]0 e, f7 b$ P5 G+ l crt num-cars9 @5 D( }9 y& v) T* w
[
7 k& s) E6 ~+ z; N setup-cars
6 o( m/ I+ u7 W' s p set-car-color/ C8 _4 G! ?- G
record-data
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;; give the turtles an initial speed
+ l) h' K' w V* D* W) n ask turtles [ set-car-speed ]; G# c3 N) ^ Y5 X' d- O& \
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reset-ticks
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( J f4 _( A* W- `;; Initialize the global variables to appropriate values* t- q7 s4 g( m2 s3 Q4 z
to setup-globals0 M1 _+ O3 ~. `- L
set current-light nobody ;; just for now, since there are no lights yet
( ^+ m+ v# Q- ]( t set phase 0
1 ?" ]3 A" b% N7 Y/ d Q+ X9 e set num-cars-stopped 0% a# u- w! Q) J' g
set grid-x-inc world-width / grid-size-x
R1 V7 ]1 n) \ set grid-y-inc world-height / grid-size-y7 d5 G2 [9 w2 X9 H2 Q$ \5 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+ z: [" L% m0 Q, `; w
set acceleration 0.0990 b& c5 J$ D! ]- k7 F
end9 D9 [0 i" K8 X2 ^( P) f& t8 ~
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
, I# A& Q* y# Q;; and initialize the traffic lights to one setting$ `3 F$ B2 ?$ Z5 H0 l" m& N$ |
to setup-patches
% [+ c; p- I: v# g( u ;; initialize the patch-owned variables and color the patches to a base-color
1 v( C) Z) D: }2 { ask patches( q/ x6 `# Y9 ?2 T0 k- [$ t# O
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2 S! _- b9 j0 T0 U2 |9 K set intersection? false
# Y3 e. O. K- Q" R set auto? false
: h8 M9 \* ?6 r( R set green-light-up? true
4 c7 Y, u: m( M5 g+ ]& M$ N6 k3 {& H set my-row -14 M, x( v& d0 F J$ z0 B
set my-column -19 N: G8 ?9 X+ H
set my-phase -1
6 ]- _. J; D: J: s1 v/ \ set pcolor brown + 3- f( J7 V8 D. Q/ ^9 n% G
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( j( q* b% o3 w ;; initialize the global variables that hold patch agentsets1 b; v+ H. ?' F& o
set roads patches with
, m# U9 ?4 `7 \, @! E [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ ~! F' U7 H! b9 W# Y7 a8 o) m! ] (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) C1 ^3 f9 R3 S. Q% f, ?' k
set intersections roads with
8 R4 y- i! ~) i2 p7 _6 x' r [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
. f% D2 J8 K/ A& \! K (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& [( y: L6 N9 j& R! s
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ask roads [ set pcolor white ]0 y# f' W7 V. d6 l) w
setup-intersections& r! t% U) B, C0 Y- t
end
+ a/ D! \! C4 p2 A其中定义道路的句子,如下所示,是什么意思啊?- B. H' M' a- s# h9 ^3 R
set roads patches with# |' A! @5 g, S1 c& C
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 M) Q" y; n8 Y, C; S, t (floor((pycor + max-pycor) mod grid-y-inc) = 0)], s+ E- E1 Y9 K' R! o+ ~7 t" f8 ?
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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