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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。 Y2 }3 P' Z% k4 w6 c0 a
netlogo自带的social science--traffic grid这一例子当中,
# e" Y) K X" ^globals- A d0 d: [5 g7 C0 E
[
0 J0 X& w6 B8 z: {- g% m grid-x-inc ;; the amount of patches in between two roads in the x direction
* {. v, _7 @+ ]7 T$ Y grid-y-inc ;; the amount of patches in between two roads in the y direction
: C4 N% N# L1 m: \8 q/ | acceleration ;; the constant that controls how much a car speeds up or slows down by if
3 B; b0 A5 }4 N& [ ;; it is to accelerate or decelerate) x, B7 h: N2 c( j$ T
phase ;; keeps track of the phase# g3 U- m8 {6 Q4 b5 K/ ?! T
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
2 \4 h9 @3 C+ }; ^ current-light ;; the currently selected light
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& `+ H& I& D' \+ `6 U! T/ d ;; patch agentsets
6 b- A% L9 }/ g- ? intersections ;; agentset containing the patches that are intersections
1 b5 B6 y' {0 i3 X" u* q/ L. V5 J) @ roads ;; agentset containing the patches that are roads
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turtles-own# p. R& m, y6 f8 x; [$ C4 z* Z d
[
! J/ V, ?4 Q7 h, ~ speed ;; the speed of the turtle' `6 T0 o2 r m) L: b
up-car? ;; true if the turtle moves downwards and false if it moves to the right
; z* B* Q! v% y' k7 a' S: L wait-time ;; the amount of time since the last time a turtle has moved
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& V5 N" m* ]+ ]7 H4 Xpatches-own
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intersection? ;; true if the patch is at the intersection of two roads' Y7 U0 O/ n% r; q" r3 Q
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
3 B4 f+ Y' B) b ;; false for a non-intersection patches.
+ u" Q/ r; s7 G5 J2 @7 G my-row ;; the row of the intersection counting from the upper left corner of the2 C' f- f3 R% z& v5 s
;; world. -1 for non-intersection patches.
7 }6 G6 a& {3 B0 X4 n, Q my-column ;; the column of the intersection counting from the upper left corner of the
. z) o3 K0 q8 E6 G ;; world. -1 for non-intersection patches.
8 b: {& P4 m2 G! v) K my-phase ;; the phase for the intersection. -1 for non-intersection patches.0 i# `2 Q! S* U9 n% n
auto? ;; whether or not this intersection will switch automatically.
C: Q/ ~) ^7 W$ T ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
1 s3 y, S! ]& l: O;; Setup Procedures ;;& r2 g/ c2 }" e9 C) X5 [: _4 }1 a
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
2 E! B3 g* g1 j. c;; Create num-cars of turtles if there are enough road patches for one turtle to" l/ U3 v: ~' h
;; be created per road patch. Set up the plots.
0 m) Q* l$ r) `8 k- p( [. Rto setup
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5 D8 Z! \! n0 j# E) m- s7 m. C setup-globals
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;; First we ask the patches to draw themselves and set up a few variables% A5 @0 [% v+ j+ F/ o; r x
setup-patches3 \1 x" C" O: j1 j( x
make-current one-of intersections* `6 C/ `7 {% _! c4 ~5 \8 ^
label-current
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! S9 L# a0 d( T7 X4 \* g set-default-shape turtles "car"# K2 O5 f) a* l- I; ?
. R* p; E& M' i H8 z# g: Z if (num-cars > count roads)4 N% G+ G- a/ f, \: n8 @) k, G" Z
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user-message (word "There are too many cars for the amount of "
2 _, }" T! i& q' X$ |* V% i: f "road. Either increase the amount of roads "
% u$ `& C5 J4 p- U6 } "by increasing the GRID-SIZE-X or "0 R9 @; K% p- |$ }$ E+ \% S! i( L
"GRID-SIZE-Y sliders, or decrease the "
9 D) g6 r! n9 D7 ^- @1 w "number of cars by lowering the NUMBER slider.\n"
. X9 |4 K3 U1 h& [# J4 z "The setup has stopped.")1 S5 ?% X. z& X' ~- A
stop% q" B3 S- J, V0 h5 Y x2 Z a
]
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( L( U" F1 }, f( Q ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
! b) t) [9 ]0 I: F" E, S crt num-cars8 K0 A* X- f, ?+ `" B
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setup-cars7 E$ x! w4 ]; g0 \; p
set-car-color
N: u9 Y0 v% D2 K3 u- i0 B, O record-data
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; y1 e/ Q; Y- w; R& G ;; give the turtles an initial speed$ q8 w r. ]! c8 S
ask turtles [ set-car-speed ]1 Q/ {- O" s/ Y1 A9 d$ Y( }3 ^
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reset-ticks
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;; Initialize the global variables to appropriate values) i7 {$ B# K% U1 T* B1 A9 M
to setup-globals/ Q8 ^: z7 ~5 c" M
set current-light nobody ;; just for now, since there are no lights yet
4 G: W% U" E. ` set phase 0
) p# C. h2 B6 O$ X# [0 d7 V set num-cars-stopped 0
$ F: A8 t* m# k6 Q3 y9 Q set grid-x-inc world-width / grid-size-x
) h: `; `9 H1 p3 g3 v+ o set grid-y-inc world-height / grid-size-y
3 Z$ j5 Z& Y" r
9 O3 T3 a8 a# q% d* e/ Z8 m1 z ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary& } ]) K' L# _0 R7 v8 m9 {: m! F
set acceleration 0.0993 G/ y" x* s( R$ @6 i
end0 i) I3 h4 \1 q& ^+ [
3 g% V' ?, g) ?5 k. M5 b+ G;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
! C! P# i, H2 e/ |' k;; and initialize the traffic lights to one setting9 ~4 _+ E, r, ]1 q, d) Q4 [
to setup-patches
! M0 p9 ]- |6 C% G7 F ;; initialize the patch-owned variables and color the patches to a base-color
, s! g* J& P0 }0 U( ~( T ask patches: p" X. `# A9 f8 U% y+ w0 ]
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set intersection? false) h4 V8 _2 Z$ m8 l0 X4 ?% L
set auto? false
, A- e. Y& P4 v1 u" m3 j set green-light-up? true
I% P" @- i' @) J+ H* [/ x set my-row -1
/ {4 a" s8 p/ f1 t2 g7 G set my-column -1' ` K1 S" F! N% j
set my-phase -1
. U5 S, n9 y) k0 z* i9 [4 j set pcolor brown + 3
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% x$ ~1 x1 u3 C3 k ;; initialize the global variables that hold patch agentsets A( @0 O3 s/ _1 a [5 h
set roads patches with
7 ?2 W% z! N: @. }" {3 G [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* e1 u1 H g0 N5 B9 v6 D: F! x& e (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ _/ q8 Z9 u; l
set intersections roads with: G+ b- {# A. d7 T% n
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and* t% T( s l' |0 c
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]& U+ P" h8 a @( j3 L
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ask roads [ set pcolor white ]1 z+ C; n$ v/ S$ {5 i, \
setup-intersections
! a, C0 T+ |; Q; Y6 }end
1 e8 o) m+ R. b3 A A0 F其中定义道路的句子,如下所示,是什么意思啊?
/ k5 t2 I3 r6 e& N set roads patches with
& v# s' p- p9 B [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 r/ T. `# ^9 r1 y5 p, { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 I8 n3 x+ j$ ~' q5 e6 \1 m7 g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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