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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。4 z% m- O6 u- h1 N5 X
netlogo自带的social science--traffic grid这一例子当中,& U% I/ \9 f* b# }* X- W1 J
globals
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I( f5 f( G8 [1 Q A9 e grid-x-inc ;; the amount of patches in between two roads in the x direction0 S/ |$ ]1 m0 F/ g: J$ e- ]
grid-y-inc ;; the amount of patches in between two roads in the y direction
7 B& X) B6 X: R& s! R acceleration ;; the constant that controls how much a car speeds up or slows down by if
; Z; o1 S4 J7 J, c2 q. b4 } ;; it is to accelerate or decelerate4 q1 I+ x" _! H1 ~/ O
phase ;; keeps track of the phase' D. ?: K) S0 ]
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure+ i) `0 d1 T2 t/ Y$ f0 _
current-light ;; the currently selected light
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) s; |7 D9 s5 Y! z! Z ;; patch agentsets }/ o. Y. r& O. J
intersections ;; agentset containing the patches that are intersections# x) d4 B/ V. f: C8 R! `, \
roads ;; agentset containing the patches that are roads
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2 V6 y. R9 b1 Q* f7 c/ S: E l" B5 sturtles-own
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speed ;; the speed of the turtle
# I# P0 H( B$ ^) F up-car? ;; true if the turtle moves downwards and false if it moves to the right( Q% r9 X9 b) l
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own5 X z; @- w) B- {8 {# |8 y$ l
[
+ Q* k. y: ^8 \5 i t intersection? ;; true if the patch is at the intersection of two roads) C0 p7 ^! y4 g! }
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
' Z; t( l. q0 p5 Z& X ;; false for a non-intersection patches.
% n4 O, K8 X" z* ?8 _* e my-row ;; the row of the intersection counting from the upper left corner of the
# B9 ~+ [9 Z7 b) y- w$ F% B ;; world. -1 for non-intersection patches.! n2 O; I8 L! N9 U8 E, q* y% c V
my-column ;; the column of the intersection counting from the upper left corner of the
& z; D& l" y" t# d ;; world. -1 for non-intersection patches." X+ p! B5 o: t" O+ i
my-phase ;; the phase for the intersection. -1 for non-intersection patches.2 j/ N7 U' q9 j" _. s' A& R
auto? ;; whether or not this intersection will switch automatically.8 }2 w5 N# F5 N# P# ^$ v& y6 P
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
. h! Z1 ~' A! n$ k;; Setup Procedures ;;
3 K4 g9 O$ U W: g0 [/ K$ M2 S2 u;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
8 d7 A {: B; @3 I: c \" t; a6 V;; Create num-cars of turtles if there are enough road patches for one turtle to( ]4 N* b6 Y/ P3 K: n) o- y
;; be created per road patch. Set up the plots.
) [4 P3 d' b; H) ?/ S- M8 a$ `9 lto setup
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: p+ V7 m M* e% h2 Q7 Q5 i5 g- ]! _ setup-globals
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;; First we ask the patches to draw themselves and set up a few variables4 [+ }; L m& Z, Q
setup-patches* C- |, Q* b- u' I" A
make-current one-of intersections4 [ p9 `6 O2 v+ M4 n
label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)5 D. _! t' `! S4 O3 g
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user-message (word "There are too many cars for the amount of "
5 _9 i6 F1 O/ Q4 N8 z "road. Either increase the amount of roads "
, T9 w' k4 I7 t& i" d "by increasing the GRID-SIZE-X or "- P M+ i1 d9 P3 O2 K9 ~% s1 e
"GRID-SIZE-Y sliders, or decrease the "
- H: r, I( Y8 D0 K% M "number of cars by lowering the NUMBER slider.\n"( \0 d# ^9 P' B, Y
"The setup has stopped.")
7 u' T* H" \- Z: w6 H" U3 W stop
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/ c$ N) e0 r8 ~ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
' ~! Z7 v) a8 {" M( g/ X) C$ M crt num-cars
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3 d9 N9 F) N/ V0 n. o2 { setup-cars& p$ M/ ~' d, i! l
set-car-color
4 k1 z6 M/ ^6 u/ r) k# S+ F8 G record-data
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1 m6 K& [. [# I# f, y ;; give the turtles an initial speed; C2 C3 j6 G/ }1 g8 d) r8 [+ z. N
ask turtles [ set-car-speed ]4 ^% Y, F" H# X8 i% T0 }
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reset-ticks
% B* X+ g! i! |3 Z mend
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2 E y) X/ }" M3 X, j% ?7 z C! d;; Initialize the global variables to appropriate values- p/ L9 U% k% L2 w
to setup-globals) L% x7 ~9 ~# r/ ?7 ~/ T
set current-light nobody ;; just for now, since there are no lights yet# t0 A4 M! [) z$ y6 o+ y; E
set phase 0
* D7 n# | H, R: v set num-cars-stopped 0
! O e- w6 {6 |; @( I+ }. o set grid-x-inc world-width / grid-size-x0 j! v9 `9 d" E; w. a$ d3 ]8 \. E
set grid-y-inc world-height / grid-size-y2 }7 {/ S* k# O: w7 i
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
$ ^7 L& v |8 C0 A8 ]4 S* X) l set acceleration 0.099+ a: b1 @2 |# z& b& V
end" d1 k% w' c. Q% [
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,& R' l5 ^* Y/ T
;; and initialize the traffic lights to one setting# A; T' Y# J8 n% P3 Q# w
to setup-patches7 U6 q. \+ B+ F T- z2 T
;; initialize the patch-owned variables and color the patches to a base-color% b* _. i8 A; @
ask patches
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set intersection? false& C K q# D+ H3 u
set auto? false
, z/ }0 w/ |* f, g$ l5 x* T set green-light-up? true0 e c" [' Y! a5 M
set my-row -12 |% I) Q* u3 g0 r) F! Z8 a0 m
set my-column -1
9 {% F. f% h; h; G+ X set my-phase -1
2 C, {! m1 j. O4 ? set pcolor brown + 3* m3 K P2 Z6 {& C
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# d3 Y+ |0 [1 ?% z6 U/ ] ;; initialize the global variables that hold patch agentsets
; l+ ]1 z0 a. e7 n% j2 O set roads patches with
! x0 a. E6 D: b( ?6 a2 f" J [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" k' X: T2 c7 p7 _5 ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)], Z0 J6 q2 X5 I! p E! s
set intersections roads with, ]6 [/ b5 G0 c8 M' r) v' A1 u4 V
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and/ U! d) n& s! B* ]4 u* x$ r
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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2 J: ^0 {) e4 aend. ]8 y+ z* W5 G
其中定义道路的句子,如下所示,是什么意思啊?& P3 b* m. I5 j. G# |# }% D" ?$ b
set roads patches with
3 {( K7 l# ]- X [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# V) \; x9 M2 V/ J2 o
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' z1 J4 K: u8 \, P; 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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