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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。3 Q1 z7 M2 h7 T3 o' m
netlogo自带的social science--traffic grid这一例子当中,' C3 {1 _% v6 z9 h# }$ v
globals
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- V" O; _6 u# s1 j3 m& `1 o, l grid-x-inc ;; the amount of patches in between two roads in the x direction2 @4 `4 ~1 ]/ j( \; q# }
grid-y-inc ;; the amount of patches in between two roads in the y direction
1 D+ n0 H6 V4 \1 ? ~ acceleration ;; the constant that controls how much a car speeds up or slows down by if
2 ~# M2 n" s3 g ;; it is to accelerate or decelerate9 V3 }$ i8 R4 O& q v; ]
phase ;; keeps track of the phase
7 Y# H# W) Q) | num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure' U3 G: O0 G: `5 a# ?7 c
current-light ;; the currently selected light2 E N7 C0 \. B
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;; patch agentsets } g$ H4 J2 |# ~$ C: p1 P: {
intersections ;; agentset containing the patches that are intersections
- k6 ]& `' B* m: j roads ;; agentset containing the patches that are roads
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turtles-own& B8 j5 M/ p, b3 ]# a
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speed ;; the speed of the turtle
# S+ j1 y0 A6 U# X- ]! G up-car? ;; true if the turtle moves downwards and false if it moves to the right
' _; i, x9 z( o' Q1 y; q( B wait-time ;; the amount of time since the last time a turtle has moved( G& w1 t6 ]' p9 z: p
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0 m7 V6 C+ D! N" H" Gpatches-own
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( [+ h- Q, E: n- G& K intersection? ;; true if the patch is at the intersection of two roads7 `% q1 ?+ t6 q" B* y6 d
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
" S' W( J# g# `- p* L ] ;; false for a non-intersection patches.$ |# P [" o1 R3 K I6 ]' {- S
my-row ;; the row of the intersection counting from the upper left corner of the; r2 U" b: h0 R; G6 i
;; world. -1 for non-intersection patches.
' i2 i; P$ x3 u* L3 u- d% z3 k my-column ;; the column of the intersection counting from the upper left corner of the
9 P- ?1 K/ L0 i8 ? ;; world. -1 for non-intersection patches.
5 i ?& O# ]% U0 i my-phase ;; the phase for the intersection. -1 for non-intersection patches.& ~4 Y9 |, q7 h/ }
auto? ;; whether or not this intersection will switch automatically.
5 r0 b' _2 t( s9 C$ ~4 }- T! H/ S. } ;; false for non-intersection patches.& X( n/ H" ?' x$ Q, k) i( N, T
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$ F; [" q' n, L4 y7 x* W8 r: w;;;;;;;;;;;;;;;;;;;;;;- q8 `" M: @" l2 R. ?
;; Setup Procedures ;;* V( r+ R1 O$ s3 b c) ~
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;; Initialize the display by giving the global and patch variables initial values., u# N; s* J* O: k3 Q, { |" ~+ ~
;; Create num-cars of turtles if there are enough road patches for one turtle to
3 k" f/ S4 }! I/ ]0 ?. g! e;; be created per road patch. Set up the plots.$ L2 Y- W4 c5 I) m4 G: n1 _& h. U
to setup
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( ?3 d9 E' O2 n. U setup-globals
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' [: [8 k; F' F% n3 |, a3 O. X ;; First we ask the patches to draw themselves and set up a few variables
0 X8 ]* t3 H' V1 [ setup-patches9 E/ N. p! ?5 |7 Z( i/ g7 H' j
make-current one-of intersections
9 q2 N( M# |& |. ] label-current" ]1 F! a, ?1 \# C' A
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set-default-shape turtles "car"9 t; j+ M% f2 \1 y
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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 "
: b- v) O% z/ C) J2 s "road. Either increase the amount of roads "
' ^' m, [* h' {4 I. ?8 m. P" r4 v "by increasing the GRID-SIZE-X or "
1 C7 Y2 d" e! |) s9 t "GRID-SIZE-Y sliders, or decrease the "* g2 I3 G0 G$ R" r% u8 w
"number of cars by lowering the NUMBER slider.\n"
: p0 b8 t6 r$ |5 }% E# a) x "The setup has stopped.") \$ a" m& D6 i* q. {" q2 q8 s
stop) ^; }3 G& n4 G& S+ F) F8 X
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color4 o% C2 f. r5 s5 L& U
crt num-cars( M" ^ I" h, J
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setup-cars" s* e0 i; @$ L5 @
set-car-color: K+ }) @8 p3 _; n5 B# }1 }; a$ Y
record-data; n+ w4 J; q3 w; F _$ V
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8 J5 f/ f! ]5 v6 i, z$ x: x. m ;; give the turtles an initial speed
9 R! @" q0 F6 K# ` ask turtles [ set-car-speed ]
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+ Q1 x8 o! p& X( `# s0 v1 @" B reset-ticks) I3 W) u* j( w( l1 K# [8 K
end
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, T; ?' [4 y+ A: c: z9 v% T;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet2 ?- w+ ~- I! M9 [
set phase 0- I$ l7 b% Q7 Q- h) [0 ~1 W
set num-cars-stopped 0
5 M2 W) |$ r: h1 z set grid-x-inc world-width / grid-size-x
* p$ N8 h+ T v1 Z% R, G set grid-y-inc world-height / grid-size-y5 s& w) R# z2 ~/ x" s8 M8 t
/ J5 V* U2 _* Z' H6 K& y% q ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
/ ?% M, n' D( E- ^ set acceleration 0.099
" m- B, I) V- o5 t1 ~% s, cend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,# q Y: ?/ p6 X: M/ i& Z
;; and initialize the traffic lights to one setting
& O5 E ]5 {5 {' Hto setup-patches4 l }( X0 g. Q3 ]4 k
;; initialize the patch-owned variables and color the patches to a base-color
" K: l& F2 f+ ~( N$ Q! S1 b ask patches
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set intersection? false
9 \" ^; `5 I, C" A set auto? false* i1 W4 Y0 F6 r. P2 ]2 F
set green-light-up? true
: [- C( D( ~$ T& e set my-row -1
* r% ]8 q# L, [4 q: b' w set my-column -1
/ `. K/ V4 L$ e" g% w! c. W set my-phase -1# O1 u2 e3 z' j5 O2 ?; b
set pcolor brown + 3$ A% A, n; P2 F/ ?+ s/ D
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; Y, L& n4 J) \6 k3 L3 w ;; initialize the global variables that hold patch agentsets v4 v. \9 N5 u* q8 ?; }" A
set roads patches with1 J, l) K, a6 a Y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) N1 G f3 g% Q, l& ^9 O
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ d3 ~' U) {/ u4 T8 \8 c! D/ K set intersections roads with
/ i7 a8 {( Z4 x5 T [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and+ p5 {* a4 z0 a. l
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]* A% O Y( }5 D) T: c, j& e
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ask roads [ set pcolor white ]
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8 L- T/ i6 Z8 \end: K: r- b7 G* [2 e' x
其中定义道路的句子,如下所示,是什么意思啊?
) U$ O! h' l% _. S& y* s set roads patches with! q0 i/ z! \; T/ g' J. F$ G
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# e3 N' d. T9 U4 P (floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 ^, i% g; Z! a) c: S3 y4 j; q4 N! u
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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