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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。2 `" p# T$ j8 l# N! i
netlogo自带的social science--traffic grid这一例子当中,
! A7 o4 H% r0 V2 Xglobals
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1 c9 P) g6 w R: @& R( G grid-x-inc ;; the amount of patches in between two roads in the x direction3 M; V0 H: b8 k/ K1 N! D
grid-y-inc ;; the amount of patches in between two roads in the y direction# L8 g& c( u5 v) l/ T
acceleration ;; the constant that controls how much a car speeds up or slows down by if
. E$ r$ u8 t! l$ |3 C ;; it is to accelerate or decelerate
! }8 P/ |* [7 u# A3 w phase ;; keeps track of the phase
* I1 Q8 W- `9 r num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure% S1 ^7 _- w! z& S0 S$ p
current-light ;; the currently selected light
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;; patch agentsets2 h# m: ?1 _/ z, f4 l3 @+ |2 E
intersections ;; agentset containing the patches that are intersections! b) d* @& m3 X
roads ;; agentset containing the patches that are roads! l. l: `: d9 F! X! D1 R' ]+ U
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turtles-own0 N6 ]% [) j$ X( o% J7 F9 g
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speed ;; the speed of the turtle
( O% r( |! o! Q# O/ X% z* C3 y9 b up-car? ;; true if the turtle moves downwards and false if it moves to the right
+ g3 R3 d$ `' d$ W* n6 `0 C wait-time ;; the amount of time since the last time a turtle has moved
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patches-own4 u$ Q) P% O0 N4 D. X# [
[
4 h# F1 }9 P, ?* K: O2 A intersection? ;; true if the patch is at the intersection of two roads0 d1 [6 ?; R3 h/ x: @3 C3 f8 y
green-light-up? ;; true if the green light is above the intersection. otherwise, false.' e7 }6 D9 y8 x- q: E6 ~9 H5 u+ O* }& p
;; false for a non-intersection patches." C5 b) q& o9 O. q
my-row ;; the row of the intersection counting from the upper left corner of the: L+ A4 j- p& d4 D3 t3 _) l- I
;; world. -1 for non-intersection patches.
# l$ g, ^" C) q" h! Q( {4 f- r" z my-column ;; the column of the intersection counting from the upper left corner of the/ V: g+ z% _4 y+ {9 g
;; world. -1 for non-intersection patches.9 @, G9 L1 d) R- ~. S+ T
my-phase ;; the phase for the intersection. -1 for non-intersection patches. N/ o; z7 ]+ \3 i- i$ X
auto? ;; whether or not this intersection will switch automatically.
( E' W: ~' D+ b, d" a9 Q ;; false for non-intersection patches.4 |7 r. P, T& t: @& x% M/ O
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8 v, z% M" U( _: ?/ I7 q;;;;;;;;;;;;;;;;;;;;;;% m* z2 d: U# P4 H" o, U' O
;; Setup Procedures ;;: ]2 y8 P4 R) g" b2 }+ Y- ~( S1 W
;;;;;;;;;;;;;;;;;;;;;;1 R; ] T' w, \$ V w
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;; Initialize the display by giving the global and patch variables initial values.3 }" @% I% X1 r# U6 N# k0 f
;; Create num-cars of turtles if there are enough road patches for one turtle to
& s, |; c9 {9 H/ H; g* g1 X( W;; be created per road patch. Set up the plots.
' J* }+ Q1 P4 b; H& R7 ?to setup
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setup-globals9 H. d+ c8 s& ?2 q) V7 F( g
I v( U6 ]" X q& S$ I ;; First we ask the patches to draw themselves and set up a few variables4 M5 ^3 N* @9 V! }2 G0 H$ l- F
setup-patches
3 z4 H, X% b! L, {) ] make-current one-of intersections
! \7 U- ~, |6 s2 F1 S$ S9 e label-current
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8 S" D1 @! b7 Q# D set-default-shape turtles "car"
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" B1 }& L3 _1 y& f0 h. g if (num-cars > count roads)/ m" b+ v8 W1 h9 y' j; U
[
9 _4 o4 j! W" }2 M user-message (word "There are too many cars for the amount of "
9 D% C6 x8 L2 ^/ O- D, m "road. Either increase the amount of roads "6 ^& X5 ~3 T2 ^& D' ^, {$ H
"by increasing the GRID-SIZE-X or "
: R. e+ t. S* ~3 V& B5 L "GRID-SIZE-Y sliders, or decrease the "7 o* g1 R, J% `8 r# h
"number of cars by lowering the NUMBER slider.\n"
: R) q J4 ]: n% ~, T "The setup has stopped.") N' `0 V7 q" O& w+ F
stop
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+ G/ O* b; k6 c E ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
+ |) W7 |' N3 V, v: K7 Y; [+ t crt num-cars
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setup-cars
$ N# E) H: \' g set-car-color
- L2 c& E6 l1 C record-data
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;; give the turtles an initial speed
+ H6 l' C9 x+ `9 T, [ ask turtles [ set-car-speed ]
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$ J {4 Y! [' A9 D( R& W) e0 g5 y# j reset-ticks
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! w# M: h% q# ~;; Initialize the global variables to appropriate values8 z; d. @+ l$ i: m. l' X* H# I
to setup-globals, s* ^7 [. A$ \9 f* k
set current-light nobody ;; just for now, since there are no lights yet# d9 p6 e6 Y' g* [2 t; k+ Q
set phase 07 U) Y9 }! r$ R {9 L+ K) h
set num-cars-stopped 0) r7 ~; @; ^3 l3 j
set grid-x-inc world-width / grid-size-x
1 \8 V8 j9 ]2 `9 ^, ]8 k set grid-y-inc world-height / grid-size-y, `( V1 v! [4 j% {
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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 i+ w0 i6 T* @9 u- R+ Y set acceleration 0.099$ f2 u' B+ t! m
end8 ]3 y- u8 z+ F
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,* l, U5 I1 \( X1 b
;; and initialize the traffic lights to one setting% d1 S4 _, `# \1 N' O2 D% n
to setup-patches! I# _1 L1 ]! q7 p }7 H9 h
;; initialize the patch-owned variables and color the patches to a base-color
( ] T6 l+ y: [3 r( O) E, X, M ask patches
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5 B0 c1 n+ w1 @; W set intersection? false
1 @( a3 Y4 Y9 k& U0 J' N# P3 O/ T( l0 k set auto? false; \( R m4 K; f# ~, h- e
set green-light-up? true
; Q: r' Z# t# ~& @# X& H5 w/ n set my-row -1
; D% T! K( g2 Y8 {$ @( c% x set my-column -1
: A* k" `( j" J5 v* y set my-phase -1, ^9 L! u% ?# K( N+ i: ~. {
set pcolor brown + 3
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; @. B% z5 X' p( Y0 I4 j% } ` ;; initialize the global variables that hold patch agentsets
: v9 s: J( D0 s set roads patches with
3 D/ C- K7 z; Q' f( {) C1 f1 y" t [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' z& [: k) r* z! ~0 L. r3 r# X. k3 |/ T (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' y: o2 G. O$ [. o
set intersections roads with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]: i5 E6 Z8 [& s F6 U
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ask roads [ set pcolor white ]3 i0 q1 G1 B! C& U+ O i
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?
. C8 f( A8 x9 B7 R8 C. x( X- g0 s set roads patches with
7 e9 B8 `% E. Z4 l" M/ W [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* X9 w+ q5 f) e ~ \ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ o$ Q4 u# e2 P; H+ a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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