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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。$ J8 V0 k8 I4 u! a9 v
netlogo自带的social science--traffic grid这一例子当中,
8 h7 `) Q1 \3 E4 g9 a+ Q: Mglobals
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' m, r1 c% U: t: X! I, E! J7 V grid-x-inc ;; the amount of patches in between two roads in the x direction V! y @( K: P- m
grid-y-inc ;; the amount of patches in between two roads in the y direction
9 E }" w/ g. T! ~1 p- a3 M acceleration ;; the constant that controls how much a car speeds up or slows down by if* c2 G- h9 e7 v1 m8 q4 t
;; it is to accelerate or decelerate0 o( h# U' d' v/ W8 l
phase ;; keeps track of the phase1 K; c% H8 I$ j9 t
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
' {, m! w$ g0 l/ I9 [# A" i1 F current-light ;; the currently selected light
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8 f( m3 M3 d3 X4 y$ T ;; patch agentsets) W, U9 b$ N9 V
intersections ;; agentset containing the patches that are intersections" Z( V; [% B& h% @1 Z1 i, F7 Y% Y7 x
roads ;; agentset containing the patches that are roads9 w. C' m, F$ r7 W
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turtles-own
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speed ;; the speed of the turtle; b; E# |4 A5 T2 U/ z+ W
up-car? ;; true if the turtle moves downwards and false if it moves to the right i0 ~& E J6 b! s8 W
wait-time ;; the amount of time since the last time a turtle has moved7 b+ m, Y# X% g) y
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% g0 j3 {0 f0 n4 v9 v5 P, O0 Apatches-own G7 i2 j' c Q1 m1 K
[
7 C1 R% t+ D9 f; _- S5 G intersection? ;; true if the patch is at the intersection of two roads7 t8 ?% h+ `* a x. I6 s) j% Q
green-light-up? ;; true if the green light is above the intersection. otherwise, false.* a5 R6 ]$ G! ~, n& Q p6 Y. T
;; false for a non-intersection patches.
* P; X( Q( L, Z7 R9 m; a6 B my-row ;; the row of the intersection counting from the upper left corner of the
% A& d6 {9 C) D$ X- X5 D* P ;; world. -1 for non-intersection patches.0 I( ]+ [% n% Y5 J# p
my-column ;; the column of the intersection counting from the upper left corner of the
( y3 Q8 s3 B( K3 l4 B ;; world. -1 for non-intersection patches.
. S! w, b% E% w; m) m my-phase ;; the phase for the intersection. -1 for non-intersection patches.% t- v/ R1 L, _' n& ?0 x8 u
auto? ;; whether or not this intersection will switch automatically.
6 ~, f1 V2 D. L ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;: R1 w. [1 g7 o8 U4 L4 a% I2 k* s6 B
;; Setup Procedures ;;( y5 a, t+ E7 }9 r3 x
;;;;;;;;;;;;;;;;;;;;;;5 L q/ b3 C* e& L2 l0 E
+ x0 t" Z- v6 \3 A* J/ M;; Initialize the display by giving the global and patch variables initial values." }2 T5 v0 V2 ]2 v
;; Create num-cars of turtles if there are enough road patches for one turtle to( M, G9 E( g; B( b
;; be created per road patch. Set up the plots.& ]& g5 e E$ E* Y. Z1 c
to setup
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setup-globals, w, I# G1 G5 h0 j
9 U) E. j. G( V4 O ;; First we ask the patches to draw themselves and set up a few variables% Y# ^- O+ Y+ h
setup-patches, F1 l C* j2 O9 O" @: |
make-current one-of intersections7 j6 j; Z' M; j. C, ]7 J0 B* z
label-current
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% u9 |: r4 A' ^- ?& X4 J( h: z set-default-shape turtles "car"& c5 o( E9 e# t6 X: A( N9 U1 p
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if (num-cars > count roads)6 I6 O5 r) V9 b! D
[
( ^0 e& a$ F7 ^. ?: ~ user-message (word "There are too many cars for the amount of "+ {8 Z- p) J0 A& O2 @) u
"road. Either increase the amount of roads "( c9 I" Z+ ~- Q' N
"by increasing the GRID-SIZE-X or "
4 k$ i/ H1 o, v0 H6 G+ e "GRID-SIZE-Y sliders, or decrease the "( G, d2 U3 r1 W
"number of cars by lowering the NUMBER slider.\n": {; S) I0 q. Q. R' |
"The setup has stopped.")9 N8 @, I- b+ M7 t
stop \) s5 {1 o1 i7 q# P2 M: q
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color% x' k, C$ i( C2 x% e( @
crt num-cars
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setup-cars2 N% |5 w7 G7 T
set-car-color' v6 z& d2 x5 a+ c# g
record-data5 [4 t+ M0 b# P, S( q
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- J" \" f& E" h0 ?1 F% v ;; give the turtles an initial speed7 G0 f% B# `/ e. Q% d
ask turtles [ set-car-speed ]: r, Q5 \7 D+ U4 a
- Y# p, t- t" e, ~: V+ J3 | reset-ticks- @8 i" ]7 o* c$ a+ J6 V
end- L5 u3 _" D4 q
/ P8 k7 i) b3 l5 N' a8 _+ };; Initialize the global variables to appropriate values9 `% c7 q. a8 T: Z% Z! P
to setup-globals( n' Z: l" U' }, K5 T6 a
set current-light nobody ;; just for now, since there are no lights yet9 e, [9 Z1 Z- P% W" e1 {' U( a
set phase 01 A5 s6 {+ A1 z) |
set num-cars-stopped 0( }- u# q) d, ]
set grid-x-inc world-width / grid-size-x, F. w. c2 |! _! m* O
set grid-y-inc world-height / grid-size-y: w# t4 W, a1 z
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary- j) ]( G+ r2 |1 ]% y
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,% S' R3 c" X. \
;; and initialize the traffic lights to one setting1 z. o6 D! Y3 b' Z& @+ Y
to setup-patches$ w5 B1 j' L4 m
;; initialize the patch-owned variables and color the patches to a base-color' t8 j# c3 ~2 C4 ^4 z* P* K
ask patches
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set intersection? false; x4 K: S' _. P& m
set auto? false/ o6 v1 }& m! D- X6 ~, F+ m: e
set green-light-up? true( B" E q8 g+ O( s
set my-row -15 d+ G: l* a4 ]
set my-column -16 x/ L" q0 l# y
set my-phase -1
7 P9 _+ N: l: ^( V& a set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
' t! m/ o3 e9 Y7 T9 m8 T set roads patches with
: o4 S4 r( H ~9 b6 ~& A/ O5 X [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 P) t) U$ J8 w# p s
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ E# Y! m. }$ P5 [7 `3 Q' X& \) d set intersections roads with
4 B6 O2 }/ D( k0 p [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
$ I# l0 y! K& \! v5 F6 M! c, k (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]7 v% S* Z, ?! W
setup-intersections6 E. n: I& N6 K/ Q) k' z# v: f. k
end# _1 L( W4 [3 t* _4 C- j4 ]) b. {
其中定义道路的句子,如下所示,是什么意思啊?+ z0 M3 R; b4 ~% h
set roads patches with3 E6 D4 V. q' a* R8 S$ ~
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 K1 l" j' b& s3 n0 k. W) B J2 s (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 B @* V$ y! H' @/ ?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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