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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。# f$ _$ ] y$ d
netlogo自带的social science--traffic grid这一例子当中,9 m8 w. k+ k8 o
globals4 t3 H( `; H: t q
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grid-x-inc ;; the amount of patches in between two roads in the x direction
* ^+ Z! R! Z. ~8 H( @# H grid-y-inc ;; the amount of patches in between two roads in the y direction
9 K1 [+ |' q% \& f4 `; o! I! t acceleration ;; the constant that controls how much a car speeds up or slows down by if" c0 b1 A, c3 S9 s5 @$ W: d
;; it is to accelerate or decelerate" h1 l6 T( x! f8 k
phase ;; keeps track of the phase& b5 J+ o! H. j, s
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
6 B' m0 F1 A1 _% k. H+ c$ b current-light ;; the currently selected light5 i; H6 @/ }+ R3 X* Z
$ X! \2 d/ o; Q: `' L7 ~$ ]& a ;; patch agentsets
( n2 U$ j1 Z# |: B, P7 K" f3 C& [7 X intersections ;; agentset containing the patches that are intersections2 d4 `* E4 [' T1 F: A W3 d/ H- Q
roads ;; agentset containing the patches that are roads
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turtles-own
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& Z0 n1 U( G5 X- O speed ;; the speed of the turtle4 N9 s5 l6 _$ T! e" B
up-car? ;; true if the turtle moves downwards and false if it moves to the right
; n3 K8 r* X4 e# M# ^1 s wait-time ;; the amount of time since the last time a turtle has moved. D! p% e2 p x, [; P/ K
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& c- w I: `& ^, Y! fpatches-own
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intersection? ;; true if the patch is at the intersection of two roads7 G5 Z2 H0 `3 D( z$ U! _- q
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
, d5 G3 t9 w0 _8 w3 E+ e ;; false for a non-intersection patches.2 T+ _$ C4 Y& v7 s' J- {) }* r$ g7 R
my-row ;; the row of the intersection counting from the upper left corner of the
7 `+ `. k$ e# H ;; world. -1 for non-intersection patches.% \, |" o* v4 r' d# y
my-column ;; the column of the intersection counting from the upper left corner of the
! e" H7 f# B: I2 F- b ;; world. -1 for non-intersection patches.7 ~( J1 P- Y2 Z, U
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
5 l0 T6 ]$ a. P# c3 }5 D auto? ;; whether or not this intersection will switch automatically.! E# f' j9 V8 y
;; false for non-intersection patches.( H6 \8 S* _- B9 D! r( }! P% E
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;;;;;;;;;;;;;;;;;;;;;;0 u/ X4 y' l! p$ v% H. H3 [3 V
;; Setup Procedures ;;$ r2 u4 Y3 Q; @- U% x
;;;;;;;;;;;;;;;;;;;;;;/ e9 S e, g w% h, b' D; |2 ?
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;; Initialize the display by giving the global and patch variables initial values.
' B- e# t, f4 G, m% y/ S;; Create num-cars of turtles if there are enough road patches for one turtle to! g! i7 @0 ]# q
;; be created per road patch. Set up the plots.1 _1 n# [( k3 ]4 J0 V5 X
to setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables6 G) o3 Y8 W+ m3 k; L7 H
setup-patches
. g5 L# f1 f, x9 u' r make-current one-of intersections
1 \8 `. G P, \3 t4 ` label-current
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set-default-shape turtles "car": c- n8 N$ B+ w: e, w, J) P7 e
3 ?3 \/ Z+ W( K: v! `/ h! T) _ if (num-cars > count roads). O" d+ T5 w8 D2 r6 l
[
0 W% m' x. C/ K8 }- R& R6 ] user-message (word "There are too many cars for the amount of ", D. D3 O$ ?$ v1 I \7 P, O
"road. Either increase the amount of roads "7 { J7 l& d1 B3 l6 D) j6 E
"by increasing the GRID-SIZE-X or "& e# f' S2 s1 P( X `4 m6 U
"GRID-SIZE-Y sliders, or decrease the " Q: ?- x2 B7 Q$ \1 n! w
"number of cars by lowering the NUMBER slider.\n", v! n+ j7 O9 j2 z; t. }" ^
"The setup has stopped."); R& l* s$ a7 _+ r2 L% [- U
stop, ?. U; w# H* |! n5 x
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?- T, `+ p4 I7 \ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
, d' ^/ C3 S1 E/ Y crt num-cars) O/ j) o+ q* j% L
[
* L2 ~* U2 ]' g setup-cars
7 V+ {4 t5 y# o set-car-color
4 F4 ]: d, f6 ? record-data9 l4 i% c+ T) N# X4 Y+ C' Z! B7 `2 j
]
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5 E. K% l7 {" q' |* f; V ;; give the turtles an initial speed
# e6 U' ~2 u' z) K( h ask turtles [ set-car-speed ]0 V* H" p* X# Y6 Y6 s
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reset-ticks
9 c) x9 G4 U( A% G7 |$ Cend
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;; Initialize the global variables to appropriate values/ j; m9 @) N% Q4 z' J M
to setup-globals! ~, c- L; G% h" x
set current-light nobody ;; just for now, since there are no lights yet: c+ J$ x$ D* k' [9 t9 n6 p$ m1 E
set phase 0: v9 d6 E& S0 J* \! _4 X
set num-cars-stopped 0
! l) U) o+ j: i& o% z set grid-x-inc world-width / grid-size-x
- B0 k3 ?7 D) t0 g! ` set grid-y-inc world-height / grid-size-y, y! d% W+ l+ S: W) w! N: w: l
; h5 b8 b1 I e j ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary5 r' C$ [- `0 V0 d8 \& h
set acceleration 0.099
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4 l+ Q, \1 l* }& g8 ^;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
/ f: I4 d/ z- }% ^% U' ^;; and initialize the traffic lights to one setting
R- |% n7 H" L$ }# H- s9 f/ B+ Uto setup-patches N. [/ L8 \* }1 `
;; initialize the patch-owned variables and color the patches to a base-color
6 u8 C8 \1 V6 i9 y) P ask patches2 P- Z& I, C! |. q+ r/ \* D0 a2 ?
[
7 B8 X% E$ f, S3 B0 g% W! R* b: `1 [ set intersection? false
: _& _$ f4 _2 I set auto? false
& X' x9 j1 @1 r3 T+ y( A set green-light-up? true! c1 L( m8 G. H) O1 Z) l$ M" x
set my-row -17 @1 n1 n4 O' i
set my-column -18 q" E; M) S: f8 E) c7 I4 f" B; H" g
set my-phase -1
7 ^5 z! q- p9 Z! {9 }* V j set pcolor brown + 36 b: m6 e; Q. b- ^4 v' j
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;; initialize the global variables that hold patch agentsets4 V7 i! q$ L2 V
set roads patches with! U2 g# d7 d. v4 O
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. D. |' r9 p' M! ?- ]2 y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 k! `$ d4 f O$ Z3 o
set intersections roads with- T, X" I' a3 n$ _" S* K' j/ b" f
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and5 |- ]$ s2 A! D
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 ~7 W* `# j/ p; h
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ask roads [ set pcolor white ]
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! ]. p$ w3 V* Z其中定义道路的句子,如下所示,是什么意思啊?
1 \2 F- z4 e; m* _ p4 ~ set roads patches with
( t, {- P/ \, a6 ?# N' t [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' o* s p, k. Z) h3 K, T (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, A; ^3 O# q0 c! T& Q* q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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