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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。' H/ O" `3 i# U2 O) l" \
netlogo自带的social science--traffic grid这一例子当中,, ^9 s4 P- u+ }6 c. v
globals. |! h, Y) K' s' H" b
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grid-x-inc ;; the amount of patches in between two roads in the x direction
" G- L' H5 c* ~# F H% N grid-y-inc ;; the amount of patches in between two roads in the y direction
' U e4 N& {9 s3 Z7 d' U acceleration ;; the constant that controls how much a car speeds up or slows down by if$ Q" s/ [( [- P9 ~( }- M
;; it is to accelerate or decelerate, P# D( K% n& l
phase ;; keeps track of the phase! n) a# e: w. U" X
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure2 g# Y( J' O# Y
current-light ;; the currently selected light
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: y) r! k! n" V& I8 Z ;; patch agentsets& g6 O5 v1 Y: p9 }7 `
intersections ;; agentset containing the patches that are intersections8 ?, t6 e" X; t& U2 I4 _; p
roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle! M% M8 S/ J. @9 g) u
up-car? ;; true if the turtle moves downwards and false if it moves to the right; \9 @3 Z; F9 v1 O/ R+ S
wait-time ;; the amount of time since the last time a turtle has moved& }5 E$ h9 g3 h) Z" P
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) E( s. Q6 t; k" Kpatches-own) h4 v# T5 D9 d" S
[
( k4 m6 x+ _! { intersection? ;; true if the patch is at the intersection of two roads
- P- |" q6 R$ j' Y* S# G t( Y green-light-up? ;; true if the green light is above the intersection. otherwise, false.0 [5 a: F5 J5 D5 h2 ^' ?
;; false for a non-intersection patches.0 a2 F( S% N8 O- N' [ G+ m# F
my-row ;; the row of the intersection counting from the upper left corner of the: D) W1 |% `3 O' b& B$ S! x
;; world. -1 for non-intersection patches.
2 W2 y1 v& K$ r6 H- V my-column ;; the column of the intersection counting from the upper left corner of the
) P+ A4 b1 { A" e ;; world. -1 for non-intersection patches.8 I9 M& x$ n6 f" m" ^# @# |2 M
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
2 q( k* W/ J* D auto? ;; whether or not this intersection will switch automatically.
4 U; ]: r# F- K" W2 i ;; false for non-intersection patches.5 }% C2 J7 q5 I8 B/ F# C
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) z! K: A0 `8 H6 U;;;;;;;;;;;;;;;;;;;;;;
1 x! Q- u' A3 v. A;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values. A0 a0 w5 t" f6 Z& x
;; Create num-cars of turtles if there are enough road patches for one turtle to& y" H9 v3 H% e# @# J" {% R- O0 h( {
;; be created per road patch. Set up the plots.7 C C; e( A4 }) Z
to setup/ ~) K; [5 y: Y/ y) h
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setup-globals
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% R9 T! e% _1 [- X ;; First we ask the patches to draw themselves and set up a few variables7 J# k! `1 r3 S6 d3 o( l
setup-patches0 P' H; v7 c; q2 N( N4 f8 E
make-current one-of intersections* O; D L* {2 D, V
label-current
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set-default-shape turtles "car"
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) ?6 \! L, ?! w, ]% J if (num-cars > count roads)9 n6 D0 K3 k3 U1 R/ L% H
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user-message (word "There are too many cars for the amount of "+ W! u+ h1 @9 u! p, ^
"road. Either increase the amount of roads "' c3 O* L5 h9 _4 {
"by increasing the GRID-SIZE-X or "
" \' a2 V0 j8 M: d "GRID-SIZE-Y sliders, or decrease the "" S3 r& U$ T. M. O7 H) D% S2 G$ [
"number of cars by lowering the NUMBER slider.\n"
2 Q7 `3 b3 U0 z* @ "The setup has stopped.")$ F0 e0 |9 ~+ w* q* Z$ x3 {/ F
stop. G/ U" y* n; V
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: Y4 t" T5 I8 d N0 x ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
2 y" L2 b, f4 _+ }4 G crt num-cars
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setup-cars
) ^8 _, j; x5 L2 B0 v4 b set-car-color
* L v+ y% P p% _" U' o record-data! s. f3 V& }1 G5 P
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O. t' X3 s: ~5 L ;; give the turtles an initial speed
5 R. ^& k5 f6 ?: O- t3 x% e% ] ask turtles [ set-car-speed ]
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reset-ticks
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# F6 g G1 f- D8 m) U' ^% [;; Initialize the global variables to appropriate values
1 p; [( V+ F: k/ Y5 R) d3 P0 Ato setup-globals; g! F c, m1 v5 C# v6 @0 Y+ f/ u
set current-light nobody ;; just for now, since there are no lights yet4 [. X7 {* f' S% v) p
set phase 06 `5 d1 P- F7 w6 b$ ~! V
set num-cars-stopped 0+ L7 S2 ~6 }- n7 m
set grid-x-inc world-width / grid-size-x
- y r. d4 u/ v; n, ] ^: _ set grid-y-inc world-height / grid-size-y% X6 @3 p+ W$ L$ @$ s5 l
) U8 f4 ~1 p3 F* p: h. }! U ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
+ a2 b7 V- m$ Q) I/ _( ` set acceleration 0.099
3 H4 l4 U- d; h- `' gend! F! [( n. D1 R- _
j% p8 K6 z6 |& `3 _) I! `;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
4 F2 g: M" w' ?;; and initialize the traffic lights to one setting0 h; X0 h6 z$ Q& I U! s; E5 k
to setup-patches7 `* l/ V& l3 T" p) u2 o5 K! e
;; initialize the patch-owned variables and color the patches to a base-color
* V4 ]6 L5 v0 T7 s# F ask patches
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set intersection? false
: g/ i/ j$ `7 q: ~ set auto? false
9 ^* m9 z: R# F) N set green-light-up? true8 O+ K) i# m7 ^/ k0 G$ G, @9 i1 s: b
set my-row -1
8 V8 `$ c* |0 M# q I- Y set my-column -1
" Y5 S# J& c) [ d set my-phase -1
7 f9 P6 S* `7 |1 { set pcolor brown + 3! T, |2 ~( m* B6 [5 P
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/ K( m% s+ }) F ;; initialize the global variables that hold patch agentsets) s; o4 g( M! G& g$ s, W7 C
set roads patches with
( Q2 M" c; Q% f% g5 w/ I) {$ p' s [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or& B: K# G% A2 U) x: d/ l
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 ~9 G9 E- ]$ x3 n, z$ P
set intersections roads with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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end# a: Y' s! k/ I& r! r5 q6 b: M- _
其中定义道路的句子,如下所示,是什么意思啊?' p# {) {9 I) Q1 t. D' Z. ~5 O
set roads patches with
8 m X, w9 e! ]: x* w, [0 H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or1 I) w: k, g" S1 t
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 t/ n [" k" N$ s( I A$ E4 |
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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