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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 J+ Y r" s; Y& d/ Bnetlogo自带的social science--traffic grid这一例子当中,, i7 _2 V) @% r7 d* v) }
globals4 k* \) t( w; F1 A
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grid-x-inc ;; the amount of patches in between two roads in the x direction
# O! f6 f2 j+ d# c/ \7 X grid-y-inc ;; the amount of patches in between two roads in the y direction& l; ] i: v' t1 ^0 n
acceleration ;; the constant that controls how much a car speeds up or slows down by if
7 M R8 V" y" f9 P4 k7 b) W* j: C ;; it is to accelerate or decelerate( J8 W5 E" ^8 q x4 M) g
phase ;; keeps track of the phase
& Y% J5 a$ r& A! J num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure( X+ {: W! ?5 K/ t
current-light ;; the currently selected light
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+ r, T2 M. v, }4 N ;; patch agentsets
( x1 H; s% P; x' e# } intersections ;; agentset containing the patches that are intersections8 r+ [$ q3 ~8 T. u3 L9 d# u# J
roads ;; agentset containing the patches that are roads! u2 z0 }- L! l5 M
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turtles-own
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speed ;; the speed of the turtle
. g1 m" ?8 L& Z- V1 d' r up-car? ;; true if the turtle moves downwards and false if it moves to the right; u. x T3 O' S' W" D, a
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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8 I# g: E$ `1 G% O' q2 H, u intersection? ;; true if the patch is at the intersection of two roads% Q" n0 ^( ]: F( u6 V0 T- q
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
1 Y- b2 O7 m4 }5 N+ L ;; false for a non-intersection patches.
! ?" e, V3 y/ Q my-row ;; the row of the intersection counting from the upper left corner of the
$ H( j8 K* @/ ~- j ;; world. -1 for non-intersection patches.
/ b0 a$ S! p5 B) A- ^4 ] my-column ;; the column of the intersection counting from the upper left corner of the' a' ^6 J {) D
;; world. -1 for non-intersection patches./ K; x/ @. b1 p$ l L# r0 a
my-phase ;; the phase for the intersection. -1 for non-intersection patches.9 q p- V8 T3 i5 P6 B* B5 G
auto? ;; whether or not this intersection will switch automatically.1 t+ C: e0 z, f8 ^* s0 F
;; false for non-intersection patches.
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( [$ w1 x2 V8 Z! }/ d;;;;;;;;;;;;;;;;;;;;;;
, @+ E; G: G9 T: [) s;; Setup Procedures ;;6 Y+ K" Y- A0 e' L( S9 f* D* R. z
;;;;;;;;;;;;;;;;;;;;;;/ [ N# c" k" B7 I
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;; Initialize the display by giving the global and patch variables initial values.
1 m+ h( q/ ~" l& Y1 u$ W5 Q9 R;; Create num-cars of turtles if there are enough road patches for one turtle to
5 W4 z% V4 I9 j, s;; be created per road patch. Set up the plots.
/ `+ v1 O( |8 v9 }to setup
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setup-globals. O5 U5 |$ n' I+ h: W( G
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;; First we ask the patches to draw themselves and set up a few variables+ Y( r' n+ ?0 _6 \% W
setup-patches
, b; T$ o! r# Q/ u make-current one-of intersections
, x$ c. Z% ?" K+ k label-current
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. j9 W0 z& n& m) I9 C# H set-default-shape turtles "car"
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]& J* _/ ~0 v- ]8 p+ O: O9 M if (num-cars > count roads)
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3 }/ X# l6 @% o: t0 P user-message (word "There are too many cars for the amount of "
5 F# Z5 x7 T& m/ m u' ^$ `" E "road. Either increase the amount of roads "
+ z0 v% G5 I0 i2 m6 q7 `7 n "by increasing the GRID-SIZE-X or "
- Z) h& |* a6 f$ k' ?0 V) | "GRID-SIZE-Y sliders, or decrease the "
, _) M7 j B4 d5 h "number of cars by lowering the NUMBER slider.\n"5 i' V7 \# P- q( W2 q1 K" U2 z
"The setup has stopped.")9 I9 I* S: ?. l6 f M1 }" @. J
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color5 f7 c7 w( w& r
crt num-cars/ }! u; j( b7 [: }
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setup-cars
5 s9 Y8 J6 h9 z' Y set-car-color8 g3 s2 a6 `; B0 O/ K8 d' o
record-data6 Q0 e _+ x( J- q; {3 }* P
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;; give the turtles an initial speed ~- ?6 }- k8 y( L
ask turtles [ set-car-speed ]' U7 @3 ~( T4 o3 n# L/ O% v
+ B( w; y* C$ V9 Q: U reset-ticks
* W: s6 O2 a# b ^% Oend8 P3 v1 C: s' T6 z# C9 z* y
0 V' a( [' w; ?2 n6 |;; Initialize the global variables to appropriate values7 E1 W* ^" Q) l
to setup-globals
( f9 O, x# O, t/ k4 h% O set current-light nobody ;; just for now, since there are no lights yet
/ `/ r, _6 Z4 j: i- a' v J set phase 0/ u6 v K4 I( c8 m
set num-cars-stopped 04 a9 m+ U9 E( A0 O3 Z7 a* C
set grid-x-inc world-width / grid-size-x
, {9 a7 _8 u% i/ J: C v set grid-y-inc world-height / grid-size-y* u9 O6 f/ w5 q2 M# E7 ?& ]* G* |( v
# {( @: ^* i# N, s* C" L0 I ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
1 t# y7 s# W" u' n! H7 a set acceleration 0.099& d1 T4 }( ?; O& G2 O
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,. b) w# e- d! ?: F6 [! b1 W& k
;; and initialize the traffic lights to one setting1 E' B6 d/ o( `/ X
to setup-patches- W% n7 G, f$ Q. y. D
;; initialize the patch-owned variables and color the patches to a base-color* J' t9 Z2 m" U& q) H0 e9 ~, W
ask patches
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set intersection? false3 B. w8 c* `3 f9 v9 f9 T
set auto? false
( a, ^0 t1 m2 H7 L- N: w set green-light-up? true
. E/ W R- a) ^4 ` set my-row -1/ a/ p; n9 G1 n' ~. n
set my-column -1
# m. S4 L$ T, g- j4 a3 K; {0 B set my-phase -1
* g# L/ a/ f& i" |4 ]( l set pcolor brown + 3. J& Y/ m& p/ @" Q' T
]
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;; initialize the global variables that hold patch agentsets: T0 n5 s$ v1 Z: b0 o1 Z
set roads patches with
4 h; i& z3 `8 W [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, V5 Y: o! c4 J/ X% l L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 m" O# u0 v3 p% b1 p8 \
set intersections roads with1 Q8 N& V! `( P# I; y# \% g2 V
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
2 L) f2 L! O6 N) K, d (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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% I* G8 p) R8 | r ask roads [ set pcolor white ]8 }: h$ L5 f9 d. q) ?/ f
setup-intersections2 v) q% J+ ] f4 Z8 f1 {5 E
end8 m8 }! u$ N4 s+ v: ^5 [# b# ~
其中定义道路的句子,如下所示,是什么意思啊?& f8 n8 y3 a" E) Q |/ L! F+ J
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 X; C( E! }# ^3 Y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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