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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。
, S" e4 E2 b# f/ p/ pnetlogo自带的social science--traffic grid这一例子当中,
4 {% d5 }% \2 r, k, Iglobals
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. x d% S6 r/ U( l+ ^1 w1 p grid-x-inc ;; the amount of patches in between two roads in the x direction
7 w- `# p4 C2 L9 Y6 O" h grid-y-inc ;; the amount of patches in between two roads in the y direction, G# @' m, f; M& k0 ] s" [
acceleration ;; the constant that controls how much a car speeds up or slows down by if0 D) P6 }4 p7 W+ z
;; it is to accelerate or decelerate0 X( O& P4 N) J: F1 I. L/ |1 Y( B
phase ;; keeps track of the phase
U# U! \6 M6 x' t/ a+ c& z num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure5 `7 n) m( l+ f
current-light ;; the currently selected light F. E* U& T* E; C% M
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;; patch agentsets* f# _, V4 U8 S1 T. k# j5 c7 V' T
intersections ;; agentset containing the patches that are intersections
; _+ S" d9 I% n4 b6 x% O5 G( n roads ;; agentset containing the patches that are roads- b& R! H" l. i( y
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4 s' q0 i" R6 wturtles-own) @+ ~3 J2 A" O5 @
[
" J* ]: @1 _. j+ I speed ;; the speed of the turtle& I/ m4 c. Q8 c% M8 x. ]
up-car? ;; true if the turtle moves downwards and false if it moves to the right
& A+ r3 }* j% V) ~% o+ ? wait-time ;; the amount of time since the last time a turtle has moved5 t+ i# q9 X, k( v9 {' ]
]
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( y; u( Z" I2 r# B7 Q: Apatches-own( K3 b' V# b( ^. Y
[
+ W1 y8 M& u" j# V4 \7 _$ D6 T intersection? ;; true if the patch is at the intersection of two roads9 }' s! f3 K" u! F* p5 D
green-light-up? ;; true if the green light is above the intersection. otherwise, false.6 t/ Z- f/ @1 n" j8 F' k" O! i/ i
;; false for a non-intersection patches.
8 @/ c6 s% b: h my-row ;; the row of the intersection counting from the upper left corner of the
+ o7 w* ^. W7 r2 d$ y+ X- J1 K8 d ;; world. -1 for non-intersection patches." ]- X. N6 e8 D7 M% A3 K9 [
my-column ;; the column of the intersection counting from the upper left corner of the
( B7 w+ U6 {! ?' @! ?2 \ ;; world. -1 for non-intersection patches.# [1 Q2 }: U9 v+ I
my-phase ;; the phase for the intersection. -1 for non-intersection patches.' O8 [3 Z# e4 `# P7 ]: n$ |
auto? ;; whether or not this intersection will switch automatically.4 r+ X3 X1 G: R) Q0 C
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
/ j( V& ?( g4 u$ p;; Setup Procedures ;;! j. ^& P9 E7 s2 j G9 e/ Y8 }( l
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
+ Y4 M$ u9 { W$ V& b) E- }, r" Z;; Create num-cars of turtles if there are enough road patches for one turtle to
5 t5 r5 {; ?! Z' U5 e) C8 U: Q: e;; be created per road patch. Set up the plots.
; L8 H3 A& H$ Vto setup* e# e- c( }2 j9 V, S9 f* U
ca
4 u& y8 h3 e: G6 e7 Q" Y4 ^ setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
8 t! L0 p7 Y+ q& j$ W5 M" | setup-patches* [9 q' s% J, F9 f. H4 ]2 f; v
make-current one-of intersections$ d% z4 ~( `4 p# \
label-current0 y8 v; `% ~6 D' I
2 l& W' o& |& f5 A3 F$ W set-default-shape turtles "car"
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if (num-cars > count roads)3 K4 Q' j( p; ?1 z- Z' l
[
$ h$ D! J" ]5 J# {4 ?% R( X user-message (word "There are too many cars for the amount of "' h0 V* W n) s& o3 v
"road. Either increase the amount of roads "- O- q' X% k2 G8 }+ k! f
"by increasing the GRID-SIZE-X or "( L% r! X- N5 f! Y6 S1 H3 e6 J4 x* z1 j/ i
"GRID-SIZE-Y sliders, or decrease the "4 _3 m% j/ @5 u2 M) j0 n- {0 x
"number of cars by lowering the NUMBER slider.\n"
/ u; `9 {1 L: _ "The setup has stopped.")
1 g9 s9 B- P6 _3 U7 C/ L: k$ ^( b( w stop
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7 {6 g$ E) @( w/ D ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color( {$ n% [" r+ B) l
crt num-cars+ b+ _" n5 U9 o. M& K
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setup-cars
. D E2 }; c( {: n2 p; c. R set-car-color* M% ~# V: C+ x0 i; @& p+ J
record-data* U; N1 R2 S; Q: }
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;; give the turtles an initial speed
. h* a0 |3 o% `/ M8 w+ \- J ask turtles [ set-car-speed ]
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$ h6 a/ U8 _- o; p/ h9 A6 t reset-ticks0 O6 ^' c! Y& b6 a# [
end+ J1 l/ d. L+ g: m% O( B
; ?' B& M/ B' c( s1 a K;; Initialize the global variables to appropriate values
% i2 w! e. L; D4 y& Oto setup-globals
( i$ Y$ ~" R* g4 k4 M set current-light nobody ;; just for now, since there are no lights yet& Y4 r- g5 y4 W
set phase 0
0 w8 j( H! F0 |8 M/ i set num-cars-stopped 0
; L; L- W6 O! m [7 Q set grid-x-inc world-width / grid-size-x
% G1 E7 P5 z, y, _ set grid-y-inc world-height / grid-size-y+ s2 g0 M* c& Y. w# w1 @
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary" \4 o6 u$ a: v& @$ o6 q+ u0 j
set acceleration 0.0996 D" ]: d0 k% ?/ Z; a
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ V" D+ |1 `8 f( ?/ I9 [) c8 \ {
;; and initialize the traffic lights to one setting* U$ V7 |5 q/ Z; O3 Y l3 X$ ]
to setup-patches7 M* z& I- U, G. \9 w
;; initialize the patch-owned variables and color the patches to a base-color( z: P6 l$ d6 Y& N4 U- ~
ask patches; \/ a! A' s" E; n( P0 n+ ]
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) g% _" E( `7 V: H# z6 t set intersection? false
& v( e& x# k( o- e set auto? false
- ~! w% r3 E2 ^/ w" h0 R& G set green-light-up? true
; d5 `% v: ^! j( V1 @ |* j/ c set my-row -1
* H& g9 F! o* e6 o set my-column -1. g0 E+ g4 Z3 O
set my-phase -1 x! k9 t3 o4 `9 V) |
set pcolor brown + 3
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7 e" J) U; R1 b; M: H ;; initialize the global variables that hold patch agentsets+ e& P, w* E. L9 h
set roads patches with' f% H# H% S8 I5 h$ p
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
+ l" c4 p! d$ ~- ~. ]7 o' G: j6 A" x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]" W' T* ]! t" t* o% D. z
set intersections roads with
1 y' ~/ u$ [6 r [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and" O( t* X' ^* J5 x; H
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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end6 }$ e! z) j5 _9 ~* f B
其中定义道路的句子,如下所示,是什么意思啊?: K7 W$ U4 E( G1 W' Y- v$ }
set roads patches with
' w, H2 U2 d4 E; s/ k [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- u& M( B4 {, \" h, G9 S (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& l8 e' C3 D! @
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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