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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。
: o, U9 m% B! Z+ Unetlogo自带的social science--traffic grid这一例子当中,3 [7 z/ c7 W. Z) k1 d: T
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
' @- V! b6 U3 U& j( T grid-y-inc ;; the amount of patches in between two roads in the y direction9 W4 k6 E. O2 M8 I, n# [
acceleration ;; the constant that controls how much a car speeds up or slows down by if
3 i6 P# m' X# g0 _6 T ;; it is to accelerate or decelerate3 t4 L+ G8 D* W7 G" \8 }
phase ;; keeps track of the phase( S' }4 M, ^5 i" b: d! \
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure, g# ^ g& O4 @' w; i2 b
current-light ;; the currently selected light% u4 d6 W* F$ l1 `4 F* _" B; l
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;; patch agentsets
2 ?4 P( q/ F4 W h intersections ;; agentset containing the patches that are intersections2 z+ U, b; y: \7 P X% L& d1 t) J k* I
roads ;; agentset containing the patches that are roads
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turtles-own
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: X8 a2 ?4 m% T& t, q, s speed ;; the speed of the turtle+ e# H+ V4 A- D! u; W4 q9 G+ n9 d
up-car? ;; true if the turtle moves downwards and false if it moves to the right" c% w/ }' i4 H! I- b6 g
wait-time ;; the amount of time since the last time a turtle has moved5 u4 [9 C$ X& w2 s. \
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patches-own& G3 r3 N9 B6 r" i2 v1 r; d% Y
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intersection? ;; true if the patch is at the intersection of two roads
9 o) a) i9 \% O7 X& @- H0 B7 b* i green-light-up? ;; true if the green light is above the intersection. otherwise, false.
' K" A1 m+ i' `4 y ;; false for a non-intersection patches.. ]; U3 I( ^ P2 G
my-row ;; the row of the intersection counting from the upper left corner of the7 ?8 K+ S$ K7 U# P- a8 F( V( y, `
;; world. -1 for non-intersection patches.7 r1 Z2 c3 p7 Y% L. J
my-column ;; the column of the intersection counting from the upper left corner of the) V) j/ X) t9 S. V' ~; X+ U
;; world. -1 for non-intersection patches.9 c- u9 g9 Q. f1 M4 k! u4 s% B
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
+ T' _; `3 ]7 r/ b& a( j9 L# X1 z auto? ;; whether or not this intersection will switch automatically.
# W E y( k. v, A) q% c( w ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;4 a+ W7 r. x8 ?- A9 t+ h. k* t
;; Setup Procedures ;;7 S1 p( E) X- s ]
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;; Initialize the display by giving the global and patch variables initial values.3 H/ S- W2 E0 f. ]7 N# O' ^
;; Create num-cars of turtles if there are enough road patches for one turtle to
4 X8 n7 _. z7 ^$ O: x: F$ [# I& b- |;; be created per road patch. Set up the plots.
6 h7 [" c) L9 A- cto setup
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# M; r+ n$ O0 w setup-globals
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5 a6 I: @% q. X. U, {, v- j9 p9 ` v ;; First we ask the patches to draw themselves and set up a few variables, }, M; {( [$ I. R/ ]
setup-patches
3 q2 v" K; B |- e& w' k make-current one-of intersections8 O0 z- T* f; a9 G- |7 N, p( P) l- j
label-current+ }4 O, {& Y. O3 \9 p) y6 f
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set-default-shape turtles "car"
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: P6 ^- k2 Q8 N; z8 L# @ if (num-cars > count roads)! g7 a6 c' P3 ^0 K
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user-message (word "There are too many cars for the amount of "! t. w& q% y; q( W! E; h0 `
"road. Either increase the amount of roads "! M: J3 H: K! Y5 l' [1 V
"by increasing the GRID-SIZE-X or " E; k/ a, ~0 q6 ]* Z' y, [0 m
"GRID-SIZE-Y sliders, or decrease the "
! s u2 o+ V. s% k" [ "number of cars by lowering the NUMBER slider.\n" f; }* ]& ?% {! W+ g- W
"The setup has stopped.")
" I3 j _/ O# j" s/ O4 I9 C- `* g stop
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/ g: C4 p. w& K' x ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
" f Q4 @5 l1 F7 y- _, t crt num-cars; e: y1 e* S& O4 B+ w6 u
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setup-cars
, i5 k: ~- ~$ ^% ?3 {4 I set-car-color" W( m% K' o3 e
record-data
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( L7 D8 _* s. g" }# M5 J ;; give the turtles an initial speed
( v! F5 \3 i: Z) x* x ask turtles [ set-car-speed ]$ O% q/ t% g. v1 m0 d1 @( u g7 A" M
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reset-ticks0 X, y* b2 M# K; X$ Z! H7 h
end
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; `+ P! G2 {$ w a( l7 j8 P;; Initialize the global variables to appropriate values- }7 Q$ Z0 m$ m
to setup-globals
) w" A' z$ r+ }, i: v set current-light nobody ;; just for now, since there are no lights yet
, J6 d( `+ y9 w, G! o. \* ~ set phase 0" p# {! m r7 J1 l9 I! a
set num-cars-stopped 0
! f, F" U" s, k7 J set grid-x-inc world-width / grid-size-x4 M' W/ z6 t) h2 {- `( l9 l' f
set grid-y-inc world-height / grid-size-y& u! E) J [: z) z( W
1 K% \9 r/ v! E ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary' i8 g; j. K0 P4 C( `5 T5 q K
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,# E a1 G4 R+ j! p) I7 M
;; and initialize the traffic lights to one setting
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;; initialize the patch-owned variables and color the patches to a base-color) S! \$ e2 g) ` Q8 i
ask patches
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set intersection? false
5 k. I. u- {' P6 v8 x" }$ ] set auto? false
- o8 ~- F0 g0 g& ^" _( s& X, }- d set green-light-up? true1 d' i5 O/ ~$ ?
set my-row -1
4 I1 @9 b1 C7 ^ set my-column -1
3 Z4 I8 O1 N4 Y, `% O set my-phase -1- |. y5 D8 o7 ]% Q3 w% q
set pcolor brown + 32 p+ \5 q3 Y1 u- |; T0 Z' b
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;; initialize the global variables that hold patch agentsets3 Q' `7 C. _! n! d
set roads patches with
- B) V. S+ b5 r1 D [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; P; m; ]4 R9 g' I (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" _# A( P' m6 Y set intersections roads with" R% Y# D" `- k1 t1 `3 @% b/ Y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
0 h4 @7 I: E5 P: t. }; Z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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V9 ?) E y. ~" ~" _9 w ask roads [ set pcolor white ]
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! i4 V6 g$ l9 _) ~end
" l* I5 X1 K# I其中定义道路的句子,如下所示,是什么意思啊?
' x/ B5 x# X& d3 y" ] set roads patches with
7 @( X/ U8 ?' J [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 G. R% ?7 i8 ^; l4 f# d$ S0 h* b (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' z* x# C0 w: u( X2 L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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