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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。' R5 Y8 z4 C! ^4 k# D0 o
netlogo自带的social science--traffic grid这一例子当中,; ^; p% j" A6 K( V9 T
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
* y: T( P4 {" C: n' ? grid-y-inc ;; the amount of patches in between two roads in the y direction
" K3 P7 W& w; T6 A# E8 \3 C* H acceleration ;; the constant that controls how much a car speeds up or slows down by if
9 z Z. r" N. W5 ~9 x ;; it is to accelerate or decelerate
! z4 m; v- B% m/ ?+ x% `& d; n/ } phase ;; keeps track of the phase
. Z2 F% d0 f: F" \7 {1 _ U num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure: x! _, Y: ?1 S' D- y1 b- L
current-light ;; the currently selected light7 s+ `# d1 x8 A E$ Q
3 v7 g C8 [4 b- K- j ;; patch agentsets/ E& _' i5 }6 Y+ H3 O" d7 q: u
intersections ;; agentset containing the patches that are intersections
/ j# }8 _ k" c$ g roads ;; agentset containing the patches that are roads4 Y4 \7 k7 k. c6 {9 h
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turtles-own
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speed ;; the speed of the turtle
8 B9 L; _' S4 T, L up-car? ;; true if the turtle moves downwards and false if it moves to the right9 t4 v, M1 t9 Z9 Y. a5 D
wait-time ;; the amount of time since the last time a turtle has moved
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$ W" U" {, W5 U7 E! f! apatches-own, q+ U& C4 q# F1 N' ]
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intersection? ;; true if the patch is at the intersection of two roads
6 ~. v4 r( _# u k' |1 Z. u& b; E! [ green-light-up? ;; true if the green light is above the intersection. otherwise, false.
1 B9 }4 e) K' _, R1 o ;; false for a non-intersection patches.8 K+ A6 m& A' p6 O5 z4 L7 f
my-row ;; the row of the intersection counting from the upper left corner of the9 n# i, F7 i2 i
;; world. -1 for non-intersection patches.
1 T5 x9 b" H7 _5 o" t& U my-column ;; the column of the intersection counting from the upper left corner of the7 A+ b. K! I$ S2 Y
;; world. -1 for non-intersection patches.4 Q$ T; E* S9 ?
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
4 T; b! P4 W9 T& H7 ]9 [* H% p auto? ;; whether or not this intersection will switch automatically.
! Y/ h- M2 {5 v! h ;; false for non-intersection patches.6 }3 C& Z4 G3 C5 n
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;;;;;;;;;;;;;;;;;;;;;;" K! ^; k: j" A
;; Setup Procedures ;;1 D& t0 F* `% |, C8 ~( \/ p4 c* ~
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;; Initialize the display by giving the global and patch variables initial values.5 ~% h [+ {# z
;; Create num-cars of turtles if there are enough road patches for one turtle to
+ Q* ^. L0 @' V/ x;; be created per road patch. Set up the plots. ^9 M8 \# P' b* i& B+ H
to setup2 W" g# y7 q" x0 Y, a
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setup-globals+ P; p. I I' R! v5 ~2 S+ V1 _7 C' J; a
/ X( G# D( U, a5 D$ |+ S ;; First we ask the patches to draw themselves and set up a few variables: Y" x: B8 g! z$ x" n" w2 e, P( }
setup-patches" o2 |5 v' o, i/ K* Y. ~
make-current one-of intersections. S- M2 N5 v. C* N5 b7 r( f- K# K
label-current
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set-default-shape turtles "car"9 Q# h Z2 x6 S8 m! [% x) \
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if (num-cars > count roads)) O5 T& O. I( e( I, [
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user-message (word "There are too many cars for the amount of "" A2 b$ N# N1 b9 b$ G+ W
"road. Either increase the amount of roads "
) u6 @# M5 y, e! U3 s "by increasing the GRID-SIZE-X or "+ A1 U5 U. T$ c/ d0 h' x5 I
"GRID-SIZE-Y sliders, or decrease the "
$ {6 m2 X- o- S6 a' f "number of cars by lowering the NUMBER slider.\n"
. W! R' H, Q- B7 F0 l* p" J "The setup has stopped.")
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/ U1 B4 I2 i @2 a3 ` ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color! j6 |: S$ g3 u" x6 C
crt num-cars) N7 x) }* S) `9 q/ o& o
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setup-cars
& c0 s8 g3 e0 |7 G1 Z- o" D1 u E! z set-car-color
5 e. `2 {! O ?% g record-data
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; `; K9 D: b! @ ;; give the turtles an initial speed
& e/ P/ I: x+ v7 I% d ask turtles [ set-car-speed ]
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reset-ticks T& J- {' X; B/ {: y, @6 {
end$ L) b. t3 Z" x
3 x+ M; X2 M$ V" a" c8 {;; Initialize the global variables to appropriate values
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9 j; [* B* `# E" A, ?; ~0 y- | set current-light nobody ;; just for now, since there are no lights yet
( g! Q: ]0 e3 u- G$ s' g( [ set phase 0! R1 A6 r0 W% }
set num-cars-stopped 0
' k2 B6 I( m8 r% n, f set grid-x-inc world-width / grid-size-x
4 G2 k& K! a# h6 j/ I set grid-y-inc world-height / grid-size-y
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0 a& V. I6 `' T9 P r ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary3 n& `6 c' E' l2 H
set acceleration 0.099$ Z. S" z+ [2 f# _, `6 s1 ^7 p9 P8 P
end
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8 M. C, _; A- i; g;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
) u7 H3 y- r! l- A1 u; F7 q: `;; and initialize the traffic lights to one setting
% E5 h- g! O/ ito setup-patches
- D% O$ g4 s6 E4 r9 N, k, Z c5 K" k ;; initialize the patch-owned variables and color the patches to a base-color9 y8 K6 ~( X5 W6 F- Q; ~ Z& f
ask patches4 J* r/ |" A( H5 T& @$ ~, {
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- \& X5 H* W6 z/ k7 R set intersection? false
4 a: v, i" Y! H- w set auto? false/ g9 Z& J$ [6 F8 U" z4 |
set green-light-up? true1 ^! S T1 x9 ?0 ]
set my-row -1
4 P! u B# ^* }* M/ a6 z set my-column -1 v& ]# e7 u: j7 n- W2 z
set my-phase -1
# ]( G! N6 u8 t; M set pcolor brown + 3
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% j0 c) H1 n6 n7 P- E5 P ;; initialize the global variables that hold patch agentsets
6 r8 v0 V, Q$ D6 P I* g- d set roads patches with0 l5 b, `4 j" ?
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or7 l$ Z* w2 D2 Y( S3 V
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 e: R/ X/ m6 A F% v* ^
set intersections roads with
* n/ e7 y& m$ b9 b% U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
( n3 P* E; T6 O4 {& N+ z (floor((pycor + max-pycor) mod grid-y-inc) = 0)] @5 u3 n+ _+ M3 }! S5 U F
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ask roads [ set pcolor white ]
- J5 i' k2 @. I) Q" a7 J* ? setup-intersections9 @1 X- _+ i8 c) m: ^
end# e- [3 }4 R6 u* P' L$ N- A: |
其中定义道路的句子,如下所示,是什么意思啊?6 c! `3 B e8 d" z# c5 \1 `
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]# T/ D4 @' l& j4 W
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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