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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。" L+ g5 _% l5 ~
netlogo自带的social science--traffic grid这一例子当中,* w8 t% x U2 ]9 E1 J" w Y- z& S: G6 A
globals; t5 G/ L H; b$ f1 o& H% ^( @
[
5 z& b' v2 E1 t1 e7 E' ?1 A C: D grid-x-inc ;; the amount of patches in between two roads in the x direction
* S- k% v, x" h. g" i, h& Z* F( ]6 L grid-y-inc ;; the amount of patches in between two roads in the y direction: @& ?' h R c# s
acceleration ;; the constant that controls how much a car speeds up or slows down by if
" k4 R: U f2 Y; k/ N ;; it is to accelerate or decelerate }/ O) \- J! g
phase ;; keeps track of the phase
8 ?- U* C; V7 z: O7 {" N. P: [1 k# ? num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure4 v/ H# }- |$ w. P5 g& T
current-light ;; the currently selected light- b' ?/ O, v" ^$ ~% t4 q. P5 W& t( V; F
+ ^% Y* l" l1 y9 \# i: J) w ;; patch agentsets
! P/ S2 k9 F* P9 S intersections ;; agentset containing the patches that are intersections
' k: e8 s. K$ I; J2 R% {" T: g roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle# L% a' }# J, `# R$ a
up-car? ;; true if the turtle moves downwards and false if it moves to the right7 Y2 _8 b" T: |- D# R* x
wait-time ;; the amount of time since the last time a turtle has moved
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0 [2 g2 Z1 s8 k& Epatches-own5 j8 Z9 @6 E. T
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intersection? ;; true if the patch is at the intersection of two roads
3 Q0 F! b- }) t9 }# P green-light-up? ;; true if the green light is above the intersection. otherwise, false.
- S2 T2 g& U% z ;; false for a non-intersection patches.
" D3 H0 H* W& d0 }; q my-row ;; the row of the intersection counting from the upper left corner of the& L* k/ v/ o2 a: i
;; world. -1 for non-intersection patches.
5 i; i2 u$ k' z- ^4 H my-column ;; the column of the intersection counting from the upper left corner of the
! j2 l0 z W4 H8 o9 m5 l ;; world. -1 for non-intersection patches.
% ~! X4 ~5 g# F6 H3 c3 H' s my-phase ;; the phase for the intersection. -1 for non-intersection patches.
7 S9 m2 P2 g2 b/ [6 R auto? ;; whether or not this intersection will switch automatically.# D r) Y5 X4 w9 w2 {: a$ i
;; false for non-intersection patches.
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* e" s& F1 T; Q: _% Q2 b;;;;;;;;;;;;;;;;;;;;;;
5 i6 x' r# l1 v" V1 B1 s;; Setup Procedures ;;$ `) [( Y2 v$ |! ~# b+ g$ e7 ]
;;;;;;;;;;;;;;;;;;;;;;' s8 i- A, U# e" f. W) V, F
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;; Initialize the display by giving the global and patch variables initial values.; [" F) m* K" l( P
;; Create num-cars of turtles if there are enough road patches for one turtle to
' [+ X+ A2 A, C+ J a; |;; be created per road patch. Set up the plots.
. l3 W( Y& |6 H U* A z" S3 l2 vto setup. J, \. W1 y# N1 u7 e8 S9 d
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setup-globals; d$ A0 L- Z [
5 o) f% u) R. d3 {3 ^% |- x! k ;; First we ask the patches to draw themselves and set up a few variables
5 v) x/ g% X, j% _ s3 R0 D, p6 D setup-patches
# A7 T& j2 G W) ]; f/ m make-current one-of intersections/ q+ c- G2 \6 a' _
label-current( J+ z" c; s+ \% U: C
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set-default-shape turtles "car", O3 s, W$ K; S6 P4 s2 U
( }* N% n( U; {, L1 E: a P if (num-cars > count roads)& U% S' U5 M: ~1 z5 ~
[
& |( s5 ~" ]! G [( ~) U user-message (word "There are too many cars for the amount of "
. u$ D N, X* l* o0 c) k6 O8 q "road. Either increase the amount of roads "
8 x# _$ v# L3 k [- R% K# t8 u- L "by increasing the GRID-SIZE-X or "
. I' n! r' E3 [6 ]4 v& M "GRID-SIZE-Y sliders, or decrease the ". S) P) @: z% F: r4 h
"number of cars by lowering the NUMBER slider.\n". W s1 o% U& O; a2 j2 @
"The setup has stopped.")6 X# m2 O3 X( W( M% s3 Z
stop- x% Q7 K e0 g( ^8 a8 d' T
]
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4 K/ Y( m l$ b- c& O2 M ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
5 b; R; i$ M' u6 E& z1 q crt num-cars! P( K# V5 o& D
[
" c2 ^! s8 s$ i$ e/ o# q" e' P) | setup-cars, @2 v5 F* W+ ]- H) v/ |& C
set-car-color/ E: k1 {- P: m: e9 M8 W' r+ R
record-data
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;; give the turtles an initial speed
5 `+ i9 i/ G$ c; o ask turtles [ set-car-speed ]2 Z" _7 y/ P8 u7 T0 w9 ?
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reset-ticks( E. R" g. H6 i. ]# _6 i" [
end
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;; Initialize the global variables to appropriate values, B" Q& s4 V: i0 `1 y- D
to setup-globals( W+ D( ~0 c$ d$ J ]; s. g
set current-light nobody ;; just for now, since there are no lights yet
! A- k+ E& L' ^ set phase 0' Z, ]/ j5 y; R6 Y+ f
set num-cars-stopped 0
+ d0 J& n2 p$ o+ V% K" g set grid-x-inc world-width / grid-size-x
5 V# Q2 s/ ^2 X( g3 {8 H set grid-y-inc world-height / grid-size-y! k* {2 Z7 m. O! O. C8 i" w
# f$ w" s2 D p2 U1 @ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary$ ?. y* g, u2 a3 G* Y# Y# l- U: a
set acceleration 0.099# c0 R2 b. f; f
end
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- ^8 J5 o6 y' w7 [, X a# S;; Make the patches have appropriate colors, set up the roads and intersections agentsets, f1 O1 ~0 }- _0 K# L% O
;; and initialize the traffic lights to one setting
0 h7 ^/ v& ?5 B: o5 T: Z( Uto setup-patches9 J. ~' l& o2 m* l
;; initialize the patch-owned variables and color the patches to a base-color4 {0 p- k% {! ?& C4 ^
ask patches
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set intersection? false7 f9 N/ o% B8 D+ {5 D( I, W
set auto? false
7 Q$ ~% n% x1 u% ~# @5 b set green-light-up? true! y8 q* B* S, F$ p) W$ |4 ^+ q7 Q8 i
set my-row -1
; r7 h# p3 G6 j. J set my-column -1
- J0 ?6 ~4 P% |* u. c7 J! Z3 T; |- T set my-phase -10 ` X) Q1 ]6 x$ D4 V/ J' _
set pcolor brown + 31 `3 Z2 K" g- t7 K+ |8 e9 o# \
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5 ]3 n& D5 I8 j, V: H1 e& u' _ ;; initialize the global variables that hold patch agentsets7 U" n3 d0 ?& j4 d
set roads patches with
$ b1 N; ?5 o5 B- |, v; r" b, ] [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 H) M; A0 R$ z' P5 x
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]" k6 d( B+ ^" F5 A( C
set intersections roads with; T2 n/ T$ M$ f. O& T* a
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and: C+ @" N/ D/ }- z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
3 _( T6 U% B8 ~* V; g+ B# y* S setup-intersections, G9 D2 ]1 w7 s* ?+ N
end9 M+ ~7 i6 e5 O1 m6 H
其中定义道路的句子,如下所示,是什么意思啊?
+ |. q R- a1 p7 `/ U; b8 h set roads patches with: q5 ^: {7 ?1 q- N* H
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or/ N `" o+ `$ Q3 w( n; _
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 _$ x' x, v; b' m$ 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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