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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。' x1 s2 g- |. J2 _( b9 @% d5 b4 k0 S
netlogo自带的social science--traffic grid这一例子当中,% M* o8 f. g) f: b. _& u8 o2 ~
globals
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2 e" d ^4 B& q, j( e grid-x-inc ;; the amount of patches in between two roads in the x direction
& \1 C8 u" ^. Y, Q% a; Z" [ grid-y-inc ;; the amount of patches in between two roads in the y direction
# V8 l5 g0 S) |- W7 f acceleration ;; the constant that controls how much a car speeds up or slows down by if n4 S' j9 t& g) s$ D! K5 S
;; it is to accelerate or decelerate
9 ?- h/ V" Q/ a7 N, j; P! Q phase ;; keeps track of the phase/ n* o9 W5 t$ d
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure, o W4 N: D2 t$ n, ^3 j; p$ U' o
current-light ;; the currently selected light
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;; patch agentsets$ P y3 [$ S8 {$ e: F* Q
intersections ;; agentset containing the patches that are intersections
7 a$ U0 r/ R, J: N roads ;; agentset containing the patches that are roads4 P3 u9 w' w& v- l) B1 ]
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. W, ?' M$ C Xturtles-own$ ?5 f& R0 {, i% C2 V, Z d+ p
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speed ;; the speed of the turtle4 e- g% _9 A( g3 S/ S4 q$ _+ Z
up-car? ;; true if the turtle moves downwards and false if it moves to the right% ]* a# c0 r) |
wait-time ;; the amount of time since the last time a turtle has moved2 x; O5 i* y5 W& k" E/ C
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
3 b4 q* H X: x, t green-light-up? ;; true if the green light is above the intersection. otherwise, false.
. \5 o8 }/ m0 v; R4 K6 k ;; false for a non-intersection patches.! c+ @& R5 [. J, ^5 c7 _6 I/ u
my-row ;; the row of the intersection counting from the upper left corner of the
( L3 D) K L3 R9 X ;; world. -1 for non-intersection patches. Z" } T- [# |6 c" j# w( z
my-column ;; the column of the intersection counting from the upper left corner of the
! U4 W1 p, A+ T: i' o ;; world. -1 for non-intersection patches., x' R+ _' g. _5 O
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
1 A) W1 t" H2 G' |& m auto? ;; whether or not this intersection will switch automatically.
& `! u( T& C5 b ;; false for non-intersection patches.$ e( Q6 c6 }/ K- ]
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;;;;;;;;;;;;;;;;;;;;;;
0 h: K( q/ C) [5 I- j; _& o;; Setup Procedures ;;3 o+ i- k9 R/ c# t6 E
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;; Initialize the display by giving the global and patch variables initial values.
2 v& M b$ B* D( o;; Create num-cars of turtles if there are enough road patches for one turtle to q( j4 l6 C; t$ a+ ^
;; be created per road patch. Set up the plots.2 G5 X# l$ D* `" ^/ f; P: T
to setup" c8 F8 d8 V+ S
ca
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4 U5 U& ^- S! | ;; First we ask the patches to draw themselves and set up a few variables
7 _; c3 x$ P- A, W setup-patches- W7 Z) g' ?: |5 C/ H# o' _8 s; |
make-current one-of intersections1 P5 Q8 ^( v! r6 G' ]3 [. d
label-current
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set-default-shape turtles "car"
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: D+ `0 R: p( D) [ if (num-cars > count roads)% P* v w5 l* E+ l
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user-message (word "There are too many cars for the amount of ": ]0 _+ b* O5 g' c& ~0 `( M% J
"road. Either increase the amount of roads "; P& ?1 Y. z8 x! o) P7 U7 h
"by increasing the GRID-SIZE-X or "& J. P' p! N5 s( `
"GRID-SIZE-Y sliders, or decrease the "
: G# I: T, J4 h7 m# n "number of cars by lowering the NUMBER slider.\n"6 b" z- t2 b" J' S2 g
"The setup has stopped.")
; q0 W/ q' e6 c3 d7 k2 V4 } stop
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' u4 [$ m9 E2 l5 e+ ? ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color' L& }- b( a; d6 `& N
crt num-cars! S5 V3 `5 m0 M
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setup-cars( O. L, d$ V% b- n4 O: U
set-car-color6 V, M( p0 b, l: i& n5 v; w
record-data# s- ?9 y6 a; W* `
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" R- u3 I. ]0 E- P& W8 D. y6 q ;; give the turtles an initial speed/ H1 s# M, O3 }# [- y
ask turtles [ set-car-speed ]6 w c& m8 t8 t: [- a- N. R7 @
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reset-ticks
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f" P. J1 X! x) k;; Initialize the global variables to appropriate values/ g$ V) L3 e/ U% f1 [4 p# f( ^
to setup-globals
$ q1 g. l: @! t n; m set current-light nobody ;; just for now, since there are no lights yet/ P7 ?0 `* \0 l6 L
set phase 02 b9 K5 q, f. E/ S/ B9 t
set num-cars-stopped 0' x- `# l& j% ^: e3 D. h
set grid-x-inc world-width / grid-size-x1 D' {. |: m2 k
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% I6 K; q. Y5 O1 e( X$ P
set acceleration 0.099
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5 A. R+ A% u) c8 A: w3 ];; Make the patches have appropriate colors, set up the roads and intersections agentsets,- q- M7 _9 f& N! M5 r# d. y9 U
;; and initialize the traffic lights to one setting9 w4 S6 g$ M! q, I8 R7 g
to setup-patches
1 z$ t9 X& H# _0 f' m1 e ;; initialize the patch-owned variables and color the patches to a base-color( n: g' Q2 ~7 u$ I$ q
ask patches
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set intersection? false1 C, M9 I |$ T0 W/ p* }
set auto? false. t' ?3 M# V3 c$ H
set green-light-up? true( p. V# S9 T( N: c$ K4 `6 |
set my-row -1
8 @# e' }& P7 U9 r! ` set my-column -1
2 b" S. w; G% i4 Z set my-phase -1% b: H/ A: T' A2 @6 t5 m
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
j2 I% K8 L c- G set roads patches with2 ]: ?+ l. A2 C @, A3 H
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or/ ~- N f) I. o* U
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 W, k4 ^5 u3 P* z. p0 `* G6 [
set intersections roads with( s0 B( ^% }; |0 s- a1 K
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
* c* S1 U# N, Y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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C! n! D. B& I' Y* P% Lend
, _. u! m5 I* b# Q( j: D# y" r其中定义道路的句子,如下所示,是什么意思啊?
0 Q( ]. Z& X' [; a set roads patches with
1 r. H% b2 P- ~5 B$ Q! m8 M; v [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) d9 \9 [" t6 y9 D: ?$ ]
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, w* P! l5 K- V8 Q" w+ L! y" `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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