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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。
) M( x& s8 w xnetlogo自带的social science--traffic grid这一例子当中,
# y" L+ e/ x1 N, r# J5 u9 w5 U- oglobals
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1 I- ]6 d) J& s0 n5 R grid-x-inc ;; the amount of patches in between two roads in the x direction) C9 c: \2 O/ w- `9 a- f7 R
grid-y-inc ;; the amount of patches in between two roads in the y direction
3 J% l ^8 t q; ~* _ acceleration ;; the constant that controls how much a car speeds up or slows down by if- A; J; }: j, W* i$ a
;; it is to accelerate or decelerate
; `7 D$ x/ n, L% p' k phase ;; keeps track of the phase
" |# d, E7 i1 G num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure, V6 F$ V( h& h; O
current-light ;; the currently selected light. E( z _# j- H0 |
+ U2 Y4 a2 b, |! J ;; patch agentsets0 L$ C9 l; x* f9 r
intersections ;; agentset containing the patches that are intersections
! P% @2 n8 f; @1 R, J' ? roads ;; agentset containing the patches that are roads
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1 u5 Z; _6 B0 u! G7 [, a$ dturtles-own
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; Q; R1 k' H* ^ speed ;; the speed of the turtle
) v1 H. |4 R: b3 d up-car? ;; true if the turtle moves downwards and false if it moves to the right
- V6 V7 r, M9 M8 }# |. h! _ wait-time ;; the amount of time since the last time a turtle has moved
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patches-own5 F D' a( @5 n# S6 S- ^/ Z0 a
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intersection? ;; true if the patch is at the intersection of two roads$ b4 a1 Q. b2 v, _! C2 L( s
green-light-up? ;; true if the green light is above the intersection. otherwise, false.5 U9 t3 H+ d) a
;; false for a non-intersection patches.
4 P t/ S' f$ s3 K6 k' W my-row ;; the row of the intersection counting from the upper left corner of the
9 l$ d# N/ C0 D ;; world. -1 for non-intersection patches.
9 F% q$ E6 l C% q8 S% b8 d my-column ;; the column of the intersection counting from the upper left corner of the8 U0 U, L4 t/ F
;; world. -1 for non-intersection patches.& F/ v4 c. n8 K& X7 k7 M
my-phase ;; the phase for the intersection. -1 for non-intersection patches.& L5 U% B1 S1 f- K1 x
auto? ;; whether or not this intersection will switch automatically.
9 [8 l* S% T2 f# M" x2 U ;; false for non-intersection patches.2 g" g- E: q: ~, p
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;;;;;;;;;;;;;;;;;;;;;;/ z9 J& o3 @: t. _
;; Setup Procedures ;;
% w( x1 @" t' Q8 N) K;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.9 I1 |$ z1 Z0 a- H5 |* c9 n( E
;; Create num-cars of turtles if there are enough road patches for one turtle to
8 }% V, H# q) R( M1 p; W. G;; be created per road patch. Set up the plots.
" J- }# z; Y1 Lto setup7 V8 T2 h) {* m+ {7 [) I
ca
4 X& R& H' a4 C. I" D setup-globals( r* N1 l; g2 s& X
5 ^! X/ |3 D! _4 e; O3 V ;; First we ask the patches to draw themselves and set up a few variables
; I) z/ B- }9 i( _ setup-patches* R1 Y) \* S( X0 ?5 f
make-current one-of intersections2 E+ m; P8 V' Z9 T
label-current
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. D+ o5 C! J. a( X! Q7 v) i6 z set-default-shape turtles "car"
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5 h5 |+ G( I6 s/ `9 [ if (num-cars > count roads)0 @6 Z$ L C0 d0 |+ ~0 f% [# y& i8 @
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user-message (word "There are too many cars for the amount of "7 z$ q+ S) ]/ ^- i
"road. Either increase the amount of roads "% m. F' _( ?$ f4 ?
"by increasing the GRID-SIZE-X or " f3 R1 R- R/ f5 G
"GRID-SIZE-Y sliders, or decrease the "5 U$ G8 c# n; c8 Q" U$ J5 J
"number of cars by lowering the NUMBER slider.\n"0 p$ ?' P, d0 \! {
"The setup has stopped."), k# A; p" O" `2 A* I S3 a, z; O
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color( k5 J) L# y0 g& R( |7 \
crt num-cars1 }/ V$ v+ l) ]2 @. q
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setup-cars: J' U1 r0 t/ c0 ^' Y) d
set-car-color
7 @( i0 y: Q# f& `, \" o record-data1 R/ a) }1 i- C9 [
]
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; ~, e0 G# f$ p. L, m ;; give the turtles an initial speed8 K7 t2 M0 u" x& Z# @4 [) p1 m
ask turtles [ set-car-speed ]4 t R0 o0 W4 T: v
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reset-ticks
' {6 K0 Z( M8 ~: eend
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& [) a& v3 c+ ?8 |" I5 D$ L;; Initialize the global variables to appropriate values
$ ^2 H \6 g: t+ g& Mto setup-globals
% J: g( {: N. z2 M$ f" U2 y set current-light nobody ;; just for now, since there are no lights yet z0 J9 o0 S+ Q4 u8 f) W5 [3 ~
set phase 0
5 [6 p: h/ q7 R5 \ set num-cars-stopped 0: j9 V4 U8 U( C) W6 n1 e+ ~0 K5 M* L O
set grid-x-inc world-width / grid-size-x# \% v8 _6 V/ ]* H0 F3 [- h+ x3 r
set grid-y-inc world-height / grid-size-y
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; `/ T' L+ R6 R0 ^5 z/ | ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary* c k- |" V3 d
set acceleration 0.099
" X; E. Z5 G$ ? t! kend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,7 I3 f! j' P8 k/ o4 Z R1 \% H) B# G
;; and initialize the traffic lights to one setting
1 S- T/ k* R4 g J5 M! Z- Rto setup-patches
2 p8 V) i+ V3 p' B ;; initialize the patch-owned variables and color the patches to a base-color' f0 V: J/ C$ l* V7 \6 [2 {
ask patches
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$ k" j" E O8 [% R; G0 W6 G# { set intersection? false
* |+ s: e5 A( R( S set auto? false
( H; k/ F; L" B& @. `* n set green-light-up? true
( [+ M i" Y( m! _& F set my-row -1
0 K5 K O9 `$ ]1 W set my-column -1
1 u8 Y9 z5 R+ ]. r/ A1 S set my-phase -1. `5 c4 _1 d. d# h& [' S( _
set pcolor brown + 31 g! f3 ]. D7 W/ |0 r* i
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7 h2 p. R Q; W ;; initialize the global variables that hold patch agentsets# y; N9 s& j) i
set roads patches with
' t" o& \- n7 K+ t [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 s' U/ h0 @' L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 g$ ]# ]* ?5 W% d! p2 V set intersections roads with
# j- y% \( ]' g. ]* s [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and: |9 a G! i4 I- d# H, Z3 I+ k
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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* d2 ?1 V2 G$ [; K' ^( a% w ask roads [ set pcolor white ]4 d3 ?6 F5 l/ \: J, L+ d6 w
setup-intersections5 |# L f+ z& Z: X( v- O; V
end
0 [0 p; N, }/ A* ~5 u其中定义道路的句子,如下所示,是什么意思啊?, ~% h8 ~$ Q) S! I
set roads patches with( s: n! n1 R8 u0 q% q G
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 X! C+ x r& r' P (floor((pycor + max-pycor) mod grid-y-inc) = 0)]# ?7 J5 c) K8 n# {
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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