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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 {# a" ~7 U# f, r* S. B
netlogo自带的social science--traffic grid这一例子当中,
6 ]4 D, L' B* j% y% c; K6 x7 }globals
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/ W; W/ c; A$ a y* ] grid-x-inc ;; the amount of patches in between two roads in the x direction2 s" Y- w# Y* Z2 E
grid-y-inc ;; the amount of patches in between two roads in the y direction
7 E3 z: r' Z J" P( v- B acceleration ;; the constant that controls how much a car speeds up or slows down by if; j' V& j. w/ k+ f4 J6 @6 K& F
;; it is to accelerate or decelerate
) n% }- K9 G# X j1 d' [3 Y phase ;; keeps track of the phase; ]2 t- J. [0 j" H
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
* C0 t! { z/ ?4 }( R current-light ;; the currently selected light" u; J3 a% [6 z! k
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;; patch agentsets6 P2 R' Z0 \7 t% L! i
intersections ;; agentset containing the patches that are intersections0 c- z- U7 V0 O" d/ V# _
roads ;; agentset containing the patches that are roads; l- _! j2 t' ?2 P5 X5 _
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) U* U: M% g4 T4 Gturtles-own
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speed ;; the speed of the turtle1 z3 n, Q) F8 z7 D0 W$ v! ]0 u, Y J* ?
up-car? ;; true if the turtle moves downwards and false if it moves to the right
: q5 N5 f! C. n) L1 U! d# } wait-time ;; the amount of time since the last time a turtle has moved
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; w5 `1 o+ \4 k( ?/ c# a, ?) |patches-own
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intersection? ;; true if the patch is at the intersection of two roads3 L5 w1 K. h0 r$ ~$ Z8 v' G
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
$ _% l! \1 @1 D ;; false for a non-intersection patches.
" B3 s; F: s8 R4 t my-row ;; the row of the intersection counting from the upper left corner of the( [9 v" K( B' m6 E! J O
;; world. -1 for non-intersection patches.
( ~* l5 }& D; u1 @) F$ X) p; p my-column ;; the column of the intersection counting from the upper left corner of the
# M% b2 J* e9 p* m( I& d+ y) h ;; world. -1 for non-intersection patches.
; S E `; c" v/ {# X my-phase ;; the phase for the intersection. -1 for non-intersection patches.
# t1 K6 G& Q3 H+ {: e$ c* r auto? ;; whether or not this intersection will switch automatically.
8 K: V" o! G4 l) N, Q1 g- A ;; false for non-intersection patches.2 I5 @$ a7 i. V1 ^- `( o8 b& o P
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;;;;;;;;;;;;;;;;;;;;;;
% }4 t8 k& ]* H! V9 o;; Setup Procedures ;;" C! p. d1 l9 ]6 `
;;;;;;;;;;;;;;;;;;;;;;
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# l2 K, {6 e7 [, f8 ~;; Initialize the display by giving the global and patch variables initial values.
! S) s; {5 I! [$ ^7 j& ];; Create num-cars of turtles if there are enough road patches for one turtle to2 S+ V. m6 f: n D8 K: [. z
;; be created per road patch. Set up the plots.
+ T& y7 ^& j! _5 D7 bto setup+ T; Q9 y/ W: g- u
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables. P. t5 _8 S+ C5 C- j9 W; Z4 U2 l4 V2 @8 O
setup-patches' {6 R1 m2 |, B5 o" f
make-current one-of intersections4 f+ k/ {6 h6 m) C G1 @
label-current
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* a6 L, F" @6 j$ u# a set-default-shape turtles "car"
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if (num-cars > count roads)8 Q$ x; B, E" n
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user-message (word "There are too many cars for the amount of ". W* e9 k7 ^; x/ n
"road. Either increase the amount of roads "8 z( m7 x F; v; s/ ?
"by increasing the GRID-SIZE-X or "% \3 f0 o! C' v5 \ D0 X9 ]" h- z
"GRID-SIZE-Y sliders, or decrease the "6 {4 Y/ {! }& E: n
"number of cars by lowering the NUMBER slider.\n"5 Z! B: C: }2 `# K8 X' N
"The setup has stopped.")5 K; B3 s5 {$ K6 o. f5 E
stop
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/ V, g9 z: j% G1 B l ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
! }9 t. [( U( E* ]2 h L+ Y- M crt num-cars/ c! u; P9 Y3 r0 \" A* X6 k
[
5 t: j" L# `2 K/ V. ^+ [ setup-cars
# |! Y0 C7 h7 p4 z8 Y; x set-car-color/ T% Z3 H. s$ {' x0 [
record-data
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;; give the turtles an initial speed
7 P% L$ w: i' x; i ask turtles [ set-car-speed ]& E! t: C/ [, R0 w m% z
( ]" P# [5 o2 B0 d2 @& q( H3 [ reset-ticks
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;; Initialize the global variables to appropriate values3 }' k- e' S4 |8 \
to setup-globals
2 \" T2 \6 i7 [% J" g" X set current-light nobody ;; just for now, since there are no lights yet( k; ]8 T, g1 M
set phase 02 J9 A8 ]' P9 Y; q# }
set num-cars-stopped 0
( V/ l/ V6 B9 L4 ^ set grid-x-inc world-width / grid-size-x2 F- T$ s$ ^4 ~0 k; M; d
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
' A! @3 s$ X: @' T! D set acceleration 0.099
3 T2 A( W; ?7 J ]% e9 xend, S0 I/ S* i! m7 }- ~. n
# D2 J% w- v; a H0 M;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
?/ t @% F3 j' N;; and initialize the traffic lights to one setting) G" G$ c' f; a3 L2 B9 r5 Z
to setup-patches
1 I: U4 U$ p( S8 b4 a ;; initialize the patch-owned variables and color the patches to a base-color
5 g5 M* y/ _3 Z ask patches4 F0 n* O0 s) d/ g+ B
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set intersection? false- ~0 }, ]& g, ]1 e
set auto? false4 f7 h1 P2 P5 O
set green-light-up? true
/ m+ c. k {" N3 ^& g0 f" R set my-row -1
1 x; | G7 @6 N. G set my-column -1
% Q. C7 L- ]% p+ |$ P$ S set my-phase -1, a& Z2 [# S$ C6 A- f9 c
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
" x& O& P5 `, I' d1 O set roads patches with
o' s2 k% u y! w% { [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 ?' h/ g- o5 M3 ]6 L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 t r9 W4 l' m: }' a
set intersections roads with ` @* V5 N% f8 |$ v! r; m
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
7 J3 V' n u( t (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]) s3 s, l. b$ d0 l: F
setup-intersections
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' m! h2 Z+ T! b: L( v9 `5 }+ {其中定义道路的句子,如下所示,是什么意思啊?
4 C/ U+ j' U4 `7 n2 Z) i) B' D6 h set roads patches with
& M6 [( ?1 @2 [5 B7 M& Y$ F. H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ ?' U$ m+ u5 @* c. p3 U (floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 F/ c$ V5 Q5 J X: c% _
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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