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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。. }8 n! ^5 x: ]& d' z& F# o$ m
netlogo自带的social science--traffic grid这一例子当中,
* m9 V# e4 i) h$ o$ f e7 ^4 Aglobals
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3 t2 Y% b }+ h; j& w grid-x-inc ;; the amount of patches in between two roads in the x direction, ]) T: _: y+ P+ O1 s6 V
grid-y-inc ;; the amount of patches in between two roads in the y direction! @6 Y* g3 n3 Q5 ?
acceleration ;; the constant that controls how much a car speeds up or slows down by if
; h/ e$ R5 q" \! g) J ;; it is to accelerate or decelerate4 k2 i: J! G1 ?/ `$ l% R
phase ;; keeps track of the phase& Z! f8 q3 f4 F+ L- l4 m
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
* ^; a. G c. |8 _; x current-light ;; the currently selected light9 l, p& j x% p9 k" b( z* S R8 V
5 p% f1 d/ X. O- c ;; patch agentsets
5 F+ Q* ~" _( i' H5 z0 L* v intersections ;; agentset containing the patches that are intersections
4 W8 v J9 X! {, h% T5 ^ roads ;; agentset containing the patches that are roads
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! B' Y. L4 t% [9 ~7 X# y" X# bturtles-own
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9 w- ~' Y! D) x5 C* p6 i% ` speed ;; the speed of the turtle' k# e* n) V, ?; d
up-car? ;; true if the turtle moves downwards and false if it moves to the right8 J5 v* X: V& R0 ?
wait-time ;; the amount of time since the last time a turtle has moved. e0 R) y# L1 R( C; S7 X2 B
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2 v4 d4 _/ L, ?4 j8 J$ J2 @3 ~0 S& ypatches-own
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intersection? ;; true if the patch is at the intersection of two roads
" u2 W$ Z+ t, z9 M# w green-light-up? ;; true if the green light is above the intersection. otherwise, false.! c- U3 O6 r0 {
;; false for a non-intersection patches.
6 P, @2 ~9 m- O: c my-row ;; the row of the intersection counting from the upper left corner of the! n' K) H% X0 E4 ]. C7 }
;; world. -1 for non-intersection patches.0 Y; x w/ f/ S
my-column ;; the column of the intersection counting from the upper left corner of the
/ D' t; G; v- z z r% N$ j- s& B ;; world. -1 for non-intersection patches.
4 Y2 t3 I- {0 D6 E8 @0 E my-phase ;; the phase for the intersection. -1 for non-intersection patches.
8 N7 ]( M# {) j/ Q1 l z+ s4 c auto? ;; whether or not this intersection will switch automatically./ l1 u9 p7 R9 I, z
;; false for non-intersection patches.# M, g% e& R L! ]- T
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# g4 A( U# f, S7 L' G+ x! k- M;;;;;;;;;;;;;;;;;;;;;;
K$ \5 u3 `6 Z. S5 j;; Setup Procedures ;;
/ F, m1 I- y! @& _( j;;;;;;;;;;;;;;;;;;;;;;! Y2 B( L+ R/ B) Y2 s
; R+ r6 Q$ E4 L4 P3 H% D;; Initialize the display by giving the global and patch variables initial values.
& F' Q" f- ]: J7 u;; Create num-cars of turtles if there are enough road patches for one turtle to
/ r( L* e# E' ]. m3 m;; be created per road patch. Set up the plots.8 s! z9 i+ B: V4 Z# m
to setup! v4 ~ ]1 [; {6 n3 X& Z- q
ca
( e- g. O" V0 O j: ?8 O setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
5 s7 \* D4 B. A setup-patches
" W- R2 F% X2 F$ o( O. n7 S make-current one-of intersections
$ y: B% ?, e# A& R4 c) V5 H label-current& q, P' x( J( c* M) m! ^/ h6 p" K
, r0 Z: F3 K7 s# e! A set-default-shape turtles "car"; l3 B. g2 z3 s6 a2 {6 U
1 B0 r2 y# W2 P1 O if (num-cars > count roads)# M- f# o9 E+ Q/ x4 l" ? Y
[
6 Q" F3 W0 u/ v% Y% _2 j user-message (word "There are too many cars for the amount of "4 N) m1 C1 n9 \) a
"road. Either increase the amount of roads "$ T, [3 s3 W6 v7 c! K% Z
"by increasing the GRID-SIZE-X or "
: Y! z' F) d% N; W& l0 M "GRID-SIZE-Y sliders, or decrease the ") s% F! h- F# j# ~4 X1 b
"number of cars by lowering the NUMBER slider.\n"
" O) X$ _4 s" I3 |5 W% D "The setup has stopped.")' P- X' V! }* q3 E- K" z
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
e/ d" r* z/ g, D crt num-cars( T$ A( q+ N9 S' J) Y2 X- P7 r
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setup-cars
2 P$ S8 Q: L: d4 B- j set-car-color$ r$ a. p) @$ G7 l3 ^
record-data. L+ t! j2 ~, w
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: c5 s M5 g% S/ q) R' h" Y ;; give the turtles an initial speed
1 _: T& j/ k3 B- U ask turtles [ set-car-speed ]
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reset-ticks
/ @( {5 e$ @4 Vend
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! Z& M* b5 j, ?- r! o; C2 [* W;; Initialize the global variables to appropriate values$ H: s \/ a# k( L0 d3 c" e
to setup-globals
5 `, ]0 t% i! C+ j& P2 \9 h/ { set current-light nobody ;; just for now, since there are no lights yet
* k& Q# [+ A+ \7 E/ v/ m. o, { set phase 0; B7 J+ p- v: X- a
set num-cars-stopped 06 |1 Y5 q- x8 _' }' N/ r* O7 R5 n
set grid-x-inc world-width / grid-size-x) x2 p4 W, d% x% ]0 G. ]
set grid-y-inc world-height / grid-size-y
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3 v* S' c; w& k5 k( V" t4 }( Z; k% E ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary4 n4 p" O1 k6 f% D% B( _8 T
set acceleration 0.099# Z8 C* x: s' k9 M$ p
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,- Q7 M& K/ Y. J- u, E, C
;; and initialize the traffic lights to one setting5 r& p% ^/ G! z& Q6 V" B- Z
to setup-patches
. T1 D2 x) _$ e. U! m ;; initialize the patch-owned variables and color the patches to a base-color
0 p9 `! R; Z3 q ask patches" M. ], A& y8 C2 r: m
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) L1 e, _, f: D! V set intersection? false
* p- p3 q7 m* U) f set auto? false
2 C7 ?. W0 ^& a5 z4 n) J set green-light-up? true
1 S6 v2 D% ]1 j( N set my-row -19 I, y$ `: X- Y& i3 [
set my-column -1
9 H, }$ B$ t6 o2 i7 y8 T set my-phase -1, V- y0 l. q5 H& K) M& ^
set pcolor brown + 3
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# Q! j/ a9 |( f5 l1 I' e. ~ ;; initialize the global variables that hold patch agentsets
/ V3 U" u# r7 V. H, {7 ]; K; d set roads patches with9 z+ z8 ]) q; U. z5 V1 c- g0 ^1 ?- [
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( q/ u1 l" L& f0 v2 ?; P, U/ G
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], Y6 l+ @6 Z: a" ]0 h$ f2 U
set intersections roads with- b& X. c5 G M& \8 Q1 w. |, W0 Y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and; \9 M* k% E( |0 Y& Q! s( R, ^
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], x0 Y+ X, @ J* ^
/ s; l4 @7 H" e3 H7 K3 s6 f ask roads [ set pcolor white ]
& P! M! d' ` Y, E: y# w setup-intersections
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+ U4 d- p, i) K% J其中定义道路的句子,如下所示,是什么意思啊?- j& z4 r0 U# ^# l4 [0 P! e
set roads patches with
2 N4 B1 i, D, R f p3 I5 G: f [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- R! j) V3 W& H: T5 _7 ?
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: E3 S/ l+ ^& S4 R+ O; R( R) S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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