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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 W* ~1 ^+ ~& p" C) f& Dnetlogo自带的social science--traffic grid这一例子当中,
! ^2 b4 o# X$ u! u. |- m+ ~globals7 m3 C; [- D8 f$ ~4 ^3 E# S
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' T3 V, i* [$ X4 S R0 F: ~ v0 } grid-x-inc ;; the amount of patches in between two roads in the x direction
3 ~2 L& C6 l" k6 L; v grid-y-inc ;; the amount of patches in between two roads in the y direction, h5 r+ L% s3 G6 q( Q# g1 q
acceleration ;; the constant that controls how much a car speeds up or slows down by if/ z; G+ `' I! @$ }4 N- u
;; it is to accelerate or decelerate, R( f5 E4 f6 `- B7 v
phase ;; keeps track of the phase
: E3 k' X' I, R% q, X num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
# @3 P1 ^2 J5 ]; ~7 v5 Y current-light ;; the currently selected light0 u% b8 ^# }" R' d4 Q l; X
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;; patch agentsets
$ @, A6 {7 |- h! x) u8 s intersections ;; agentset containing the patches that are intersections7 {# ~! S5 B+ q1 n& [: {$ E
roads ;; agentset containing the patches that are roads7 s" ^4 w3 W) l! P' ?
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9 O( V4 `+ m) w" ]$ _* T [- Q" b2 c1 Jturtles-own
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' p6 H& R9 O& t! N9 W speed ;; the speed of the turtle
* R# h1 }4 @. ?& E. q up-car? ;; true if the turtle moves downwards and false if it moves to the right" I, d; P- {+ [1 O# r, e
wait-time ;; the amount of time since the last time a turtle has moved
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4 ?/ D) f0 r. Q1 X; z- ^
' ]3 d8 R( o4 [patches-own
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intersection? ;; true if the patch is at the intersection of two roads& N/ N& n# p& B, y5 u* a2 W
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
: w, ]7 E; l( R- g/ X# L0 E& ] ;; false for a non-intersection patches.
& e! V, Y+ c6 g$ N' M0 J my-row ;; the row of the intersection counting from the upper left corner of the1 g0 u, Q$ {2 d6 i/ V4 n
;; world. -1 for non-intersection patches.
2 F2 N6 g* D, ]- `/ e my-column ;; the column of the intersection counting from the upper left corner of the
0 v, |- ?/ v8 K. f4 H ;; world. -1 for non-intersection patches.% m- o C' s+ T l: k4 ?- d! Y
my-phase ;; the phase for the intersection. -1 for non-intersection patches.) w" o! ~% K! Q2 _9 z
auto? ;; whether or not this intersection will switch automatically.( }: T: v: S1 Z+ O3 ?0 N1 Y
;; false for non-intersection patches.5 \- v# v0 r2 a5 B* r" Q
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;;;;;;;;;;;;;;;;;;;;;;5 f: y7 N" z" w' Y6 r$ d
;; Setup Procedures ;;) h% S8 i8 O/ D1 N3 ]# a
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
: U# t) _' ]0 d;; Create num-cars of turtles if there are enough road patches for one turtle to9 _! ^* t8 j* n
;; be created per road patch. Set up the plots.% O0 S( r8 t: w1 S
to setup0 B9 Z" m6 y. Z; }+ B
ca
7 e8 x S- j1 U setup-globals
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9 z' _* Z/ {- c( x0 `. j2 ] } ;; First we ask the patches to draw themselves and set up a few variables1 y/ ^6 D( s3 U/ e& b, R8 s
setup-patches; y- ]6 L: W. I
make-current one-of intersections
7 W3 L+ j* a* O' _: y& i! E$ h label-current$ `- b' d0 ^7 e8 b4 C( F
6 j& J! j! i& A' P8 j% ? set-default-shape turtles "car"5 \; Y, q3 u, Z' G; p. n
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if (num-cars > count roads)7 P, a6 \! H6 c+ f8 d* _
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5 d, R# C+ b+ }# p user-message (word "There are too many cars for the amount of "
" H: i# P5 U' f "road. Either increase the amount of roads "
( Z& b# o' e4 L6 Q2 Y" f; q- N' ? "by increasing the GRID-SIZE-X or "
1 ]- y1 y& u4 b; t! F "GRID-SIZE-Y sliders, or decrease the "! ]9 Y# I& B4 f4 G3 J
"number of cars by lowering the NUMBER slider.\n": ~! y# A+ Y0 v
"The setup has stopped.")
2 Q( F" t" {# v. w5 @; J7 U# [ stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color4 `) N1 i! y3 q' Q5 |8 g
crt num-cars
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setup-cars
2 `) l3 K R* m' D- P set-car-color$ V, M; h% {8 v0 a, b9 y4 X
record-data7 i' J! I5 Y _* v7 `. Z5 h1 h* U! t% v
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6 R: x- ]" ^$ o0 f. G4 f7 ^7 {3 Y! G ;; give the turtles an initial speed% _5 b. o1 g! d0 {
ask turtles [ set-car-speed ]
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reset-ticks
) ^* j( P, C6 j* _+ P9 Oend
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;; Initialize the global variables to appropriate values& v% Y1 A; P3 A! }
to setup-globals1 S, H5 x9 |5 c1 x& L: g
set current-light nobody ;; just for now, since there are no lights yet9 z z3 a2 u' P/ g: K
set phase 0
! Q0 Z& n9 F9 E# y& }& i" b set num-cars-stopped 0. \3 {* M$ X) c
set grid-x-inc world-width / grid-size-x- ?, I/ ^; a2 U, q2 E6 f/ W: z4 u
set grid-y-inc world-height / grid-size-y8 q/ s$ `4 ~* l; E6 D. P
- P( Q! D# d/ V+ U( y6 h+ @2 q ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary! H# D2 S- E+ ?
set acceleration 0.099
" y* i4 ]3 |9 }7 ]end9 F9 C6 B, ? j9 P- R" k6 X
4 v$ {0 [" S$ e* {1 Q;; Make the patches have appropriate colors, set up the roads and intersections agentsets,1 U' Z C; I o5 A6 b* d
;; and initialize the traffic lights to one setting
2 V1 l I M" r c( f1 }- V6 g+ Oto setup-patches4 j/ w( X4 E( I5 b1 x9 `
;; initialize the patch-owned variables and color the patches to a base-color
7 ~$ Q/ z4 q2 `0 Q9 _ ask patches
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set intersection? false; \& U% e q8 F8 x0 Y, D7 e! h
set auto? false
7 I4 I- D2 |% F' T7 P& ^ set green-light-up? true
( |: G% g& ~0 u$ ~4 Q: v! q set my-row -1- R+ C- j6 I6 R& i$ F
set my-column -1
7 Q- H6 w, }4 y+ ~ set my-phase -1
4 A }' s2 l; X' [" _ set pcolor brown + 3$ V& ~6 w' J& \2 G6 F
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;; initialize the global variables that hold patch agentsets+ T- `1 K( P) Y8 y7 B! |
set roads patches with
$ Q' i) N( q* K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 u, I$ O8 c4 t. n+ Y% ^" }/ A/ Z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 _. b/ g; ^1 _4 z8 V
set intersections roads with
& T, ~2 S1 M5 T- l1 H |+ T [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and* w6 Q! W0 H. n7 F7 x
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ ?' ^: l- K! Q( s2 q- R
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ask roads [ set pcolor white ]
: s3 c, w+ g% a: q1 t8 O( _ setup-intersections
7 _ l. v( l9 V; Z/ y* p! r/ w Qend$ l9 C! ~ e+ Z4 o* [& v( m
其中定义道路的句子,如下所示,是什么意思啊?
v* M8 }3 ^ ^4 }4 [6 A( @ set roads patches with
8 I0 X7 u) U4 Q; }; ]4 | [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 l* f8 ~/ B# z9 }) v4 \1 v5 t) L* B! d (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: q# ?2 {2 q' i; @; T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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