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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。: ~6 u3 @% z! p* D' H# x' a
netlogo自带的social science--traffic grid这一例子当中,. N, s3 [$ k2 e p
globals. Y$ }7 M* P2 `
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grid-x-inc ;; the amount of patches in between two roads in the x direction
' X4 n9 U7 x" D grid-y-inc ;; the amount of patches in between two roads in the y direction, l/ y& ^0 x* V* @1 P/ K
acceleration ;; the constant that controls how much a car speeds up or slows down by if
2 j0 |0 w/ Y' c5 a- |( T, X" G ;; it is to accelerate or decelerate8 G; U( `! F2 V- D! t9 N3 W. N
phase ;; keeps track of the phase
9 S2 U o4 S0 | V) o num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure4 u9 O. O# S6 W o
current-light ;; the currently selected light/ q" M! z* g3 M9 ]- t$ v% E' W* I
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;; patch agentsets
! Y D/ K) E3 p" v; C intersections ;; agentset containing the patches that are intersections
3 m: S" y1 e' G% u. m# M roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle9 E0 h U, g* Z$ q
up-car? ;; true if the turtle moves downwards and false if it moves to the right
2 ?7 P7 ^8 A# O7 o, ?% ]8 ?' u& J" o# Q wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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C+ d% m, X* Q% M8 k; x intersection? ;; true if the patch is at the intersection of two roads! T1 G! t" P, P& t. V4 i& e! I
green-light-up? ;; true if the green light is above the intersection. otherwise, false.# x7 P" j3 ]) D5 n* M+ K
;; false for a non-intersection patches.
& V+ ]& [. Q5 V3 q& L) G my-row ;; the row of the intersection counting from the upper left corner of the
% k- P& F, B+ f9 ` ;; world. -1 for non-intersection patches.
. w/ u' k: m- \$ m3 J3 i my-column ;; the column of the intersection counting from the upper left corner of the1 a- p7 n% `& a2 y% j: z) d/ z V# B
;; world. -1 for non-intersection patches.; Z7 w. L' B5 F3 [6 U# X1 M) B r
my-phase ;; the phase for the intersection. -1 for non-intersection patches.: q6 r( X ^' M+ C) H* ]
auto? ;; whether or not this intersection will switch automatically. c, B4 ?- W5 c( c& X5 x
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;/ r+ }: U) e2 }% S+ b( e4 w4 e& I
;; Setup Procedures ;;
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+ Y' Y: B' E) P;; Initialize the display by giving the global and patch variables initial values.
. r: F* h1 C+ I# |( q;; Create num-cars of turtles if there are enough road patches for one turtle to
8 x7 g# c5 W2 G8 q;; be created per road patch. Set up the plots.( [1 A* Z- v, R% J6 m- C
to setup$ e& ], h7 h+ c2 C6 R
ca
! r- G9 s; u$ i% }) F0 l setup-globals/ y/ }+ s" e. ?( ]
0 p4 |' v! y- a5 P5 x ;; First we ask the patches to draw themselves and set up a few variables
* z- {- |2 ?6 U4 _, d, A1 f+ N setup-patches
$ Y9 X5 n% r8 ~ make-current one-of intersections
6 s8 ]0 N3 D2 f! ~: \' N label-current, F$ L% v1 C: z; s
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set-default-shape turtles "car"% d/ \0 ?; x, ?# p5 y- L4 w0 m
& E' P6 h e" x' `" W8 o if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
5 ^1 G5 R5 p3 C "road. Either increase the amount of roads "8 b/ F1 x' y- B: \ I* n
"by increasing the GRID-SIZE-X or "
* b( R/ L Q3 X) \ "GRID-SIZE-Y sliders, or decrease the ") m& N" D* n$ d3 X$ n, W) J- m
"number of cars by lowering the NUMBER slider.\n"
( `' ~2 m/ n" ?: }, S& y3 f! ^" E "The setup has stopped.")
" I" w- g& V# p6 Z! d1 ^ stop5 }: Q# _/ I8 d+ a3 m
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color, e4 l9 @/ X( O- u) ^+ W
crt num-cars+ r/ s, v( |* l4 p
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setup-cars: k+ T8 I! i( X- u
set-car-color
5 `# S4 m: H, Y+ C3 { record-data
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;; give the turtles an initial speed
0 f9 \6 U3 D+ S( ?2 m ask turtles [ set-car-speed ]' @, n+ b) f% c" L
" m3 X1 \% N7 J. X reset-ticks. ^* \5 F) T* ]
end s1 ]5 l7 v4 V) O$ H8 N
6 C+ q4 v; C5 K. d% k5 Y5 _; X0 r;; Initialize the global variables to appropriate values0 ~8 U( p1 x, ?1 ]" c8 ~% m* s1 M
to setup-globals6 c1 v& D. c: E6 n& y
set current-light nobody ;; just for now, since there are no lights yet
0 j+ J( }& `+ _" T set phase 0: u2 W; q6 O; x6 Q
set num-cars-stopped 0
! X5 X) c5 d, k set grid-x-inc world-width / grid-size-x
, j* Q( E7 [/ ~) \9 S3 w set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary* }1 B% b* J, [5 p. Q4 ~% s
set acceleration 0.099; B* \; D7 [2 {9 S
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
+ }) ^3 Q3 K9 P, H( k& n! i( ];; and initialize the traffic lights to one setting
% E B s) j; j. e7 i( N- `5 _; Yto setup-patches$ p$ U. o; Y5 S" p0 d, ?
;; initialize the patch-owned variables and color the patches to a base-color
& z2 t% Q/ [. o$ _' |4 U1 ] ask patches* R7 y$ l+ Y- R+ u; ~6 J$ O% t
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set intersection? false0 ?, O+ ~& P+ I
set auto? false$ J4 L/ w9 y! L) T' f" S
set green-light-up? true
, @) ]" B$ c; E( P6 r set my-row -1
( h6 Q$ {* r( s8 A. P set my-column -1
b3 o: J+ N% o/ M9 H' n set my-phase -1
' W( m z! ^1 J7 |$ w' Y9 C set pcolor brown + 39 j x9 t0 a) ^8 W: ^, t2 E
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6 h( j7 x: O( n( B ;; initialize the global variables that hold patch agentsets5 L3 n: _: V/ x; `
set roads patches with7 d2 [ K4 @, p7 v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' W- H$ H6 }/ k6 p; i+ G (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& y! \4 I# m1 q) P
set intersections roads with2 e- f" u" x m- P; q1 @
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
7 X) ~1 w5 C+ W; G8 O (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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3 S+ i l) C0 d" C- o ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?2 T) _! Y. \( _, c) ?
set roads patches with9 k& A. ^$ t, G( T0 x+ @
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' D( r% o. B0 h& G2 J6 j (floor((pycor + max-pycor) mod grid-y-inc) = 0)]- i9 ^. k- l0 p7 Q" l; 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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