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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。
1 s0 G& c9 s0 x! h Snetlogo自带的social science--traffic grid这一例子当中,; |- n6 h) }& |) q# e4 S# S
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
6 N9 Q3 U; j7 O- b grid-y-inc ;; the amount of patches in between two roads in the y direction
' N0 b; e+ S8 N7 I acceleration ;; the constant that controls how much a car speeds up or slows down by if
5 Y1 O/ z7 z6 D: u" v ;; it is to accelerate or decelerate9 a: w( b G) {! r- t
phase ;; keeps track of the phase" A( S `3 l `3 i; q, u, k
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure* ~8 M, m2 j1 F7 K9 n) C
current-light ;; the currently selected light0 L# S: ^) T4 R c/ S+ @' l, B
4 K' G& e% g; ~* Q+ e" z; C! I1 b ;; patch agentsets
$ i) k. ^) g( i" k) P S intersections ;; agentset containing the patches that are intersections
^. h* c! M4 t( P5 g @" M roads ;; agentset containing the patches that are roads/ T" w* E' x, b0 `3 G
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turtles-own
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speed ;; the speed of the turtle9 n0 `- i8 P f) y
up-car? ;; true if the turtle moves downwards and false if it moves to the right
- X& L5 }) ]( Z5 t wait-time ;; the amount of time since the last time a turtle has moved9 p4 A6 s1 {8 y) ^7 g. g9 g* ]
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patches-own" w" r3 D/ h! B0 P' ?, u* Z3 U
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intersection? ;; true if the patch is at the intersection of two roads# i" P$ L9 p! |6 \: |" V/ v
green-light-up? ;; true if the green light is above the intersection. otherwise, false.8 V0 G' ]7 R/ z W! o% Z. n7 U
;; false for a non-intersection patches.7 a4 h, x$ ?4 ]5 t2 c3 C# p8 V
my-row ;; the row of the intersection counting from the upper left corner of the
! o7 A2 {9 d3 x* {" w ;; world. -1 for non-intersection patches.
4 T: n2 m/ i; x. q. [2 J% o8 X my-column ;; the column of the intersection counting from the upper left corner of the/ [; I2 I* K" H2 @- u
;; world. -1 for non-intersection patches.( T& `7 {. `- P, J3 \: i0 @
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
3 u M0 x+ C5 w) y. z. | auto? ;; whether or not this intersection will switch automatically.
& O2 b, }2 X; b" k8 f& S- u" u ;; false for non-intersection patches.: }5 q" g2 F8 O( X* O- K3 o/ A Q7 N
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: I5 k" ^2 s% K" ?0 R;;;;;;;;;;;;;;;;;;;;;;, z7 ] V; t" m' e1 ]
;; Setup Procedures ;;
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5 I% s6 L% `4 o- A# @, i;; Initialize the display by giving the global and patch variables initial values.& O2 b* f) h7 Y$ h5 _ j
;; Create num-cars of turtles if there are enough road patches for one turtle to4 w+ u9 ~6 S: h( d F q
;; be created per road patch. Set up the plots. q" l6 M* T& W
to setup
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setup-globals; l1 r' i' B% \! E
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;; First we ask the patches to draw themselves and set up a few variables
* @( e: C! Q- P; ] setup-patches# M, r' [0 V& X( _, B
make-current one-of intersections- x' p8 r5 n- s
label-current
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' L+ ^8 M/ ` D7 u& @! V. s set-default-shape turtles "car"( R; f, ~5 U5 t
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of " |0 a/ ?$ d g6 K* W8 e* g
"road. Either increase the amount of roads "
5 W% R) p9 [# B2 s, Z "by increasing the GRID-SIZE-X or "! U0 G. O. ?2 j# c: l1 g
"GRID-SIZE-Y sliders, or decrease the "
. Y0 Z/ e4 j6 g6 l "number of cars by lowering the NUMBER slider.\n"& W6 Q* H" q5 W( U- s- q8 J [
"The setup has stopped.")! T: o8 ~ D* o0 d! r
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color" M! T, R. t' S2 m A6 M1 p
crt num-cars
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setup-cars
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record-data4 F# k f0 I* P% v7 x) I
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;; give the turtles an initial speed
, X% Z& t( K% x6 H* I5 R! M ask turtles [ set-car-speed ]- [$ p8 V! H' P" i! D$ ~7 G, Z, H
* P9 g7 K" {5 `5 [- ? reset-ticks/ u5 t; P, i. g' K* P
end2 b- ^$ v4 I. N2 c0 j
# B/ E b& n3 t6 o# l, i2 u# z2 b4 ];; Initialize the global variables to appropriate values( L- H9 @% F, ?" X! f% B
to setup-globals. V+ c3 K6 I; b' b% _/ ^. G
set current-light nobody ;; just for now, since there are no lights yet) t/ |" A6 x. f- P/ }0 ]/ @. n/ C3 h( `
set phase 0
, {; d! q4 S( m. ^2 s set num-cars-stopped 0; ^# ?8 g; k* _# D
set grid-x-inc world-width / grid-size-x# V0 o% B$ A9 ^/ x9 |
set grid-y-inc world-height / grid-size-y
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) V7 y M% q7 l% C ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary/ y. K" T' e3 G' _# A# K. _: s
set acceleration 0.099# B. f6 v P' X6 ?
end4 y3 H5 q! _3 k8 O
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,, a S- W$ L6 \% R
;; and initialize the traffic lights to one setting
' _0 l; {& E: I1 `to setup-patches
: N' @5 ^! Z0 q. j+ s% ~) O ;; initialize the patch-owned variables and color the patches to a base-color
9 u5 o; I1 x* ?2 k6 i- V7 |$ I- ] ask patches) L# N; P% ]' s$ g1 O; V
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set intersection? false
# q. n9 F4 a" a set auto? false
, I8 K5 n& q7 {2 G set green-light-up? true5 w+ S1 N. `8 S+ g2 M$ j8 X5 B8 S6 ~9 q
set my-row -14 w" n" ?8 ^7 d! u/ P3 M7 n- }; _
set my-column -1
, [; j6 Q `" g0 n I set my-phase -1
$ L/ y8 P) ^) n* m' F set pcolor brown + 3
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# L1 `- O% K- l" I ;; initialize the global variables that hold patch agentsets
# F/ \: C1 d3 ]3 d- s5 B" j set roads patches with
0 M' B6 r% ` G6 s3 a) z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or7 M- X7 d5 T) N d. {
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ j/ K4 p; X6 U% s9 f
set intersections roads with b6 J' A/ k- r9 h. W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 n* [7 T4 Z/ m1 F) V
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], v% V: B7 }% X
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ask roads [ set pcolor white ]+ u/ x3 |( m& Y
setup-intersections; O8 v/ x! f7 ]: o3 [
end- W7 l, _% k# U. _1 V' }
其中定义道路的句子,如下所示,是什么意思啊?7 C7 l, _) i0 T }. @
set roads patches with
6 N+ k( T4 }. O [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 F) V5 T. u1 F$ l) M
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ m" e: J- }8 j9 x+ 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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