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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。, k3 K! p2 g6 y, z; b; T
netlogo自带的social science--traffic grid这一例子当中,
7 `6 n" } g( Y- \% kglobals
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) G1 _" k, X% N grid-x-inc ;; the amount of patches in between two roads in the x direction
' j3 @, b6 }6 q grid-y-inc ;; the amount of patches in between two roads in the y direction
- F: s1 Q- a( [, v* [. b4 E2 W acceleration ;; the constant that controls how much a car speeds up or slows down by if
/ L) d4 T: [$ R1 x; I ;; it is to accelerate or decelerate L' O; a1 K5 J, w9 |* y; a1 s, U
phase ;; keeps track of the phase
% ^: C) Z* L- o4 F7 Y num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure1 v( x% P: h* [' G
current-light ;; the currently selected light3 H0 ~% t$ f) ?0 f1 J9 Z6 }
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;; patch agentsets
7 P" u# ]2 B4 t, j0 o* p intersections ;; agentset containing the patches that are intersections- A; v1 a) F2 S( R. d
roads ;; agentset containing the patches that are roads4 ], z- V1 P, k, m
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turtles-own
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speed ;; the speed of the turtle! V! H" Y/ q" N; [9 H
up-car? ;; true if the turtle moves downwards and false if it moves to the right
! F7 g% ]7 W3 t! E2 f+ ~ wait-time ;; the amount of time since the last time a turtle has moved4 ]2 O% [2 a7 n! Q
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0 O+ y1 C" F, I3 H9 Gpatches-own/ h/ z* K# B" K+ t
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intersection? ;; true if the patch is at the intersection of two roads# Z' [$ b, r* U) V
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
& [6 [. V5 e8 j: B: F ;; false for a non-intersection patches.
) C& x3 Q& N* a, @1 f2 y my-row ;; the row of the intersection counting from the upper left corner of the' s# w4 B" k% |, r: ^: D) h
;; world. -1 for non-intersection patches.
( y9 N z1 N; o. y+ Z6 S- N my-column ;; the column of the intersection counting from the upper left corner of the
6 b0 m+ l4 R" p4 ~) e) R9 u ;; world. -1 for non-intersection patches.! c- ?: |$ Y, Z
my-phase ;; the phase for the intersection. -1 for non-intersection patches.+ c& T7 A/ q l' b! g
auto? ;; whether or not this intersection will switch automatically.9 ?1 ^; O0 f8 w. c9 |9 ^
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;$ t b* {) m( Z
;; Setup Procedures ;;: r7 ^; G0 Q. F9 o; t: k X1 _
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# |7 [1 a, K) J6 @1 s0 F% {;; Initialize the display by giving the global and patch variables initial values.
8 \3 o' V3 n1 n& O; A B. L" E. j;; Create num-cars of turtles if there are enough road patches for one turtle to
( f, F; u% z7 ~. b* r! s;; be created per road patch. Set up the plots.! V7 X7 X9 {% j/ O
to setup
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setup-globals' [' B, p) V, f0 f, `# x
4 x# H- H: ~* \9 D, t! Y ;; First we ask the patches to draw themselves and set up a few variables E( Z- U2 N! p9 ]2 a
setup-patches
5 {! }+ @7 J- }2 @3 g- |/ G) s- U make-current one-of intersections
9 o1 a3 N' G+ K! K) q$ h: u; d label-current: t6 T( ?( x" g8 e
! i. e& ?9 h8 W' U* x4 N5 J, F set-default-shape turtles "car"
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if (num-cars > count roads)
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8 k/ {! M: T- `9 g" k user-message (word "There are too many cars for the amount of "
+ ~: R0 r. H4 _4 p% {, ]% [ "road. Either increase the amount of roads "
0 K: g1 p- U0 a3 l "by increasing the GRID-SIZE-X or ", W/ a9 y6 y8 f6 s4 w) O; ~/ V# Z
"GRID-SIZE-Y sliders, or decrease the "+ M5 L o8 d/ m/ Z) X7 S5 X! W
"number of cars by lowering the NUMBER slider.\n"
4 G0 n& g [) d "The setup has stopped.")
0 @5 ~* d6 o3 o8 C! \: Y V stop
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+ U% O$ R' [% g$ \2 G& F ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color1 _" P! Q* |; v- }# {
crt num-cars" _$ Z0 {1 j9 |" g- f
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setup-cars
4 {, F& \8 l- ?: y2 o" w set-car-color2 r+ l& p( c: G2 c. L- {
record-data
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2 u H1 i$ A$ m: q; I% n3 A6 b ;; give the turtles an initial speed
( a$ m g9 B& G% Y3 X ask turtles [ set-car-speed ]
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reset-ticks
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8 q$ {) M% \. o/ Z7 \& @1 o;; Initialize the global variables to appropriate values
# o! U3 |- i' wto setup-globals
0 r5 G# @+ f% t) a set current-light nobody ;; just for now, since there are no lights yet
* |; E( b4 G; C0 X* r+ p. \ t set phase 0
" b- L4 H/ S& B1 f9 o set num-cars-stopped 0. D7 a* ?1 A+ d8 q6 T
set grid-x-inc world-width / grid-size-x
$ Z ^1 \6 ~( ^ set grid-y-inc world-height / grid-size-y
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6 {+ B( c r" R' l* f. ~- I ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
; \% G+ Z: F I8 e& [6 O! o0 h set acceleration 0.0991 o$ l. E- l3 w
end
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" Q! P" c/ G: q5 U Y! d; ~' |;; Make the patches have appropriate colors, set up the roads and intersections agentsets,7 @% a0 R H9 \# X8 M
;; and initialize the traffic lights to one setting2 m$ F5 `/ V6 S* Z
to setup-patches
8 J8 H% c" A% {" R: n | ;; initialize the patch-owned variables and color the patches to a base-color$ G! z X+ W0 V+ Y' ?7 R1 Y
ask patches5 d2 v* H9 I' ~9 @' F9 w
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set intersection? false. `7 M. `8 m* _5 B
set auto? false3 q; Z- I5 i; m+ W' p9 q
set green-light-up? true
$ P# a; ?! A( A- p9 q) ~0 Q3 w& Y set my-row -1
3 G/ i/ ^) l. u& b5 ?2 [% r set my-column -1
! b2 l- P: [ q5 e set my-phase -18 @( B3 |0 o0 e7 g
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets' a9 A+ p3 K Z/ f3 y( _: b' y- C* E
set roads patches with. r/ {% e5 {3 P2 J6 a+ p+ C! ?, ]
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 C7 `8 f! d0 m; t4 x9 K (floor((pycor + max-pycor) mod grid-y-inc) = 0)]# K# X" e4 a, r! M1 L7 ~7 L! p" h& Y" m
set intersections roads with+ v# c% K0 D! ?3 W/ j2 R" L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
& `$ n4 Y& [: }+ Z' d/ Q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ] ^, l, Q$ L1 K: x+ v
setup-intersections
7 j) X0 I4 h. K! I& Y$ D0 f% r* Nend
7 B; P/ G, D$ Q% a$ b5 ]/ z5 ~其中定义道路的句子,如下所示,是什么意思啊?/ Q8 m( u8 S4 h3 @. d7 n
set roads patches with7 W! d% h7 b6 Q, I4 ?: c
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 n( a' q0 H7 b3 H
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], U U, |' |9 b/ a6 Z
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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