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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。
5 R. L+ ]3 R& n6 mnetlogo自带的social science--traffic grid这一例子当中,
0 S4 O3 E0 z8 d: e6 X+ }globals& L9 j, K+ v# R- d) Y2 v
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( `3 _4 h/ K' A0 }/ R grid-x-inc ;; the amount of patches in between two roads in the x direction
) M# S8 k$ ?8 |2 F2 `# Q) y% G grid-y-inc ;; the amount of patches in between two roads in the y direction
5 E) R0 I1 G' o, u+ X2 g1 K acceleration ;; the constant that controls how much a car speeds up or slows down by if
; H& k( M: K# R9 d ;; it is to accelerate or decelerate
& B! m: \0 c: S/ o$ b: o phase ;; keeps track of the phase
7 A$ A4 K# J/ ]/ _8 \: x( s5 _ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure/ d* D' v; M" i2 G
current-light ;; the currently selected light+ }7 p# T4 B4 j5 Q
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;; patch agentsets' d2 U/ I3 v8 G" j
intersections ;; agentset containing the patches that are intersections# ~/ j0 Q/ t# _
roads ;; agentset containing the patches that are roads8 v! u. t, W" ]6 j- d( a1 M+ G+ D
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0 L) h/ X J6 H9 f" R' X: @turtles-own+ K" e+ V. \& ~* Y% e" `
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- j4 N, z3 T- U. f8 ?0 T) ? speed ;; the speed of the turtle" A% C. o8 g; l) S! C
up-car? ;; true if the turtle moves downwards and false if it moves to the right. W) r) v. r/ }5 c
wait-time ;; the amount of time since the last time a turtle has moved
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8 o* }# ~% P; Zpatches-own
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intersection? ;; true if the patch is at the intersection of two roads+ z3 e5 [2 g# i W- ~, Y
green-light-up? ;; true if the green light is above the intersection. otherwise, false.6 Y6 A2 D U4 u- V0 ^
;; false for a non-intersection patches.* J& T! ^: `# v" B+ K8 Q
my-row ;; the row of the intersection counting from the upper left corner of the
" B4 F# w9 |3 E4 X ;; world. -1 for non-intersection patches.3 M3 C4 ~9 I4 |" F
my-column ;; the column of the intersection counting from the upper left corner of the4 w4 a" t. x" Z6 C
;; world. -1 for non-intersection patches.
% X6 P* Q3 {* l Z2 F8 z my-phase ;; the phase for the intersection. -1 for non-intersection patches.
/ J' B$ Y* F( j! a8 }3 t auto? ;; whether or not this intersection will switch automatically.
* o4 ^' I2 J3 q" m: ]# p! F# K ;; false for non-intersection patches.
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M9 }, V' S' E3 [;;;;;;;;;;;;;;;;;;;;;;" p" j# R* k5 \
;; Setup Procedures ;;
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$ O0 D/ h) z1 r;; Initialize the display by giving the global and patch variables initial values.
: w, Z6 `3 ~. v& E" z9 C2 i;; Create num-cars of turtles if there are enough road patches for one turtle to* j) \* L! T6 o" N: D# ~5 G# Z) Q/ U
;; be created per road patch. Set up the plots.! ?" c9 t: [2 Z' j4 R1 e
to setup, _8 Z5 K. N: B W _
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setup-globals, A3 v: P3 w" x
8 W1 h" h6 B3 g0 O: r3 ^3 H ;; First we ask the patches to draw themselves and set up a few variables9 Y5 t5 ^8 Z1 m- [) M- O
setup-patches. _' a* c1 X) S! m/ P
make-current one-of intersections# O: c) w/ H$ M& v7 C3 \
label-current7 p, z# \- s T2 H) O( v
+ P0 E" B4 c9 G
set-default-shape turtles "car"
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& A9 b- a1 m f0 T0 i if (num-cars > count roads)% N! B* V6 Z+ m4 e
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user-message (word "There are too many cars for the amount of "
: K7 d) u$ ?6 W4 k3 e; ~) f3 M8 E "road. Either increase the amount of roads "+ ]- v# x2 l& q+ V2 W
"by increasing the GRID-SIZE-X or "7 }9 ~6 h6 J& F' k6 n
"GRID-SIZE-Y sliders, or decrease the "' _6 I m) V+ t6 v/ N
"number of cars by lowering the NUMBER slider.\n"3 H# T& i/ U! L( l4 M5 x
"The setup has stopped.")
! _7 x: q$ u1 \1 n stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
" Q! m: v( x3 A) _' V4 M; C crt num-cars1 Z5 ^: |& t2 l$ V% r [9 m
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7 Z7 x; f: z4 O setup-cars
0 y% X0 F# ~. F* a2 a set-car-color7 A3 k( Z; k0 v1 }
record-data
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+ ]& Y! S% L4 y
;; give the turtles an initial speed
& Y! d: D. j, v ask turtles [ set-car-speed ]2 A- t. _* _: G2 \. E |: Z6 c
5 S- F) ^6 R( k* V9 r9 q9 }& t reset-ticks7 ]6 Z, x2 ?4 ^, D! x5 B7 }% D
end
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;; Initialize the global variables to appropriate values. b5 z8 u$ U {! e% ~* s1 A4 ^5 ?
to setup-globals# @, g2 T& o" _" l7 t, F# T
set current-light nobody ;; just for now, since there are no lights yet6 Z% A m# R0 @5 ]4 B( v! b2 f
set phase 0
( I& |6 L! R; Y" h& _+ u set num-cars-stopped 0+ k+ \1 a, p, J* L4 X2 K) c' h5 K
set grid-x-inc world-width / grid-size-x
# C8 V7 V8 C9 z7 O& S3 m$ m8 F set grid-y-inc world-height / grid-size-y, d8 z n2 ^& q/ q. T9 ~
- }, O9 U4 m) O3 u( l ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary2 h4 |% ^' a: D; \
set acceleration 0.099$ y& Q9 C7 M0 ]3 Z
end+ m: N1 e* C& v9 H; X: B* d$ |
) ?6 k: }5 T$ N, L/ n;; Make the patches have appropriate colors, set up the roads and intersections agentsets," s. f& ]2 V, f' y) F5 V- R
;; and initialize the traffic lights to one setting
' I5 P' k2 o7 C+ t2 jto setup-patches
4 L1 W6 k& S/ C9 ? ;; initialize the patch-owned variables and color the patches to a base-color
/ ~; j) [- C" C9 a4 i% B; C ask patches0 F4 j) e% Y9 D9 d
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- q j2 u7 i; O+ V; W set intersection? false
5 V; o# s T$ c2 [5 x0 g- C set auto? false* d3 e5 O; d9 w# ~
set green-light-up? true& Q0 ]( R3 L6 t$ C {3 e
set my-row -18 F; @$ p# s. m- e: i4 e( ?9 x
set my-column -1
/ _' i5 t+ l. D% z( c8 g; G set my-phase -1' l- a% l* N! {( ?2 d8 b) m
set pcolor brown + 3
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4 N W5 e) _& d$ o ;; initialize the global variables that hold patch agentsets
- z2 u1 m1 p% w! R- X B set roads patches with& K7 W% O) w/ w" \1 @
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' @- _# @! _; A4 b% k" Y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]# ?% B* s9 g9 X
set intersections roads with6 H( ?, |8 A. \# u
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
, n5 X& q2 m- ^4 A3 } (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]( g5 u6 `1 y, [$ P
setup-intersections; W( h9 S! }, k: F3 ?, m
end
' u( v, b& j7 r# ^, S. ]其中定义道路的句子,如下所示,是什么意思啊?7 y Y; j( \$ @% L. t7 Z: n& H
set roads patches with
B2 c2 b( O! h; g0 l0 M: P) D [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 ]( T: Z: X2 v
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! X ^9 ?- {! M6 w. ?- F, e2 f0 X
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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