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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。0 J9 q' q5 `9 x
netlogo自带的social science--traffic grid这一例子当中,' `, [/ ~; }. t
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction# h1 z$ N9 l3 A* I. z2 b
grid-y-inc ;; the amount of patches in between two roads in the y direction
8 b) {8 _4 z" Y! C7 u6 O0 } acceleration ;; the constant that controls how much a car speeds up or slows down by if+ A& M0 f. F% ? x$ I
;; it is to accelerate or decelerate; y) y2 P; O) S( j
phase ;; keeps track of the phase2 I1 k& ] M( a% H- ~
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
7 Q. R* E4 b' _3 ~$ @ current-light ;; the currently selected light* e/ Q0 d/ E: B
; D# T' I( a* j- X( W ;; patch agentsets
( j H3 Q/ |7 ^. y# Y2 Z intersections ;; agentset containing the patches that are intersections
6 r d5 o1 l+ C( t roads ;; agentset containing the patches that are roads
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$ H) t1 \0 g, j2 eturtles-own
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speed ;; the speed of the turtle
0 i1 f: W3 p( }( d7 ~; W up-car? ;; true if the turtle moves downwards and false if it moves to the right4 C4 o( b0 Y( ]3 f5 G) C
wait-time ;; the amount of time since the last time a turtle has moved
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0 U0 b- b( g) d' C6 Z+ gpatches-own/ D# Q# ?, m d! _" I( M
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intersection? ;; true if the patch is at the intersection of two roads8 E" G& K! x# s9 X8 B7 ?# u
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
$ k) g; V9 F+ Y' C' F- _* E) g ;; false for a non-intersection patches.! ^/ v- g5 E+ U
my-row ;; the row of the intersection counting from the upper left corner of the- O0 F) y/ n4 E$ P( p
;; world. -1 for non-intersection patches./ ^$ v* }, A8 w1 w# [, g
my-column ;; the column of the intersection counting from the upper left corner of the
. h) O. X! z+ Y8 B ;; world. -1 for non-intersection patches.3 x2 E! u1 j% K1 \ m2 A7 h0 V
my-phase ;; the phase for the intersection. -1 for non-intersection patches.% G8 y& w: ~! _& M5 M9 j! k% V
auto? ;; whether or not this intersection will switch automatically.# ^7 Q& T2 x/ q- V: h
;; false for non-intersection patches.5 H9 p6 ?* b; d; ^: ~
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;;;;;;;;;;;;;;;;;;;;;;
4 t8 Q6 c# T& ?. ?;; Setup Procedures ;;/ k6 F7 |3 [7 u3 |. Z
;;;;;;;;;;;;;;;;;;;;;;( ^" A7 }0 T# v) ]2 A2 o% k- x
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;; Initialize the display by giving the global and patch variables initial values.
" i& N: J# Y( w* U% }) d- B;; Create num-cars of turtles if there are enough road patches for one turtle to
4 \5 W* p- R7 h2 V, e B;; be created per road patch. Set up the plots.
% D8 x5 J+ w8 v' s$ J; z7 gto setup
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setup-globals
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9 {' N& k9 h3 r/ ~& q ;; First we ask the patches to draw themselves and set up a few variables$ d: [7 ?3 P+ A5 o' h9 X
setup-patches
$ p4 f. X; g& n make-current one-of intersections; T# F7 B" w% I$ w- t# j J) e
label-current+ f8 l, M1 S' ?. @' q: V- `) ~
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set-default-shape turtles "car"( P9 N( n5 Q7 M" e
' H. c; H K; o. d6 e6 z: Y4 B" J& q if (num-cars > count roads)& p% M, k [' Z* U. }
[
& w2 ]( X' Q2 y) ]) y user-message (word "There are too many cars for the amount of "9 z0 n" K$ U3 F- @6 F
"road. Either increase the amount of roads "
$ j$ Z% m6 n6 U) K4 ~% V R+ R9 H, f "by increasing the GRID-SIZE-X or "4 o9 K( Y V4 S& ?( S( ^1 Y. P+ E7 ]
"GRID-SIZE-Y sliders, or decrease the "
( j6 k1 p, a) p6 g; K7 z1 y "number of cars by lowering the NUMBER slider.\n"
* W: \- T, ?# s% d) \8 I "The setup has stopped.")( {; ]2 A1 G' C% T6 o
stop# c7 z- S3 q; X U% e
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color ~: M, F( {+ L- h7 H* ]8 l9 v+ J
crt num-cars$ E9 u6 n% m1 a) t7 @" d
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8 _7 I; z. U$ Z7 l E0 G setup-cars
, J6 s8 x# o: K# ~ set-car-color* C. b) R* L# x v l2 j! I: W
record-data# q: P6 _" j( O V, {, }$ R
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;; give the turtles an initial speed
0 I7 v6 P0 B/ V ask turtles [ set-car-speed ]
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reset-ticks; T2 v) E$ O+ C+ G: N+ D7 x
end' e' X. b/ o5 B
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;; Initialize the global variables to appropriate values
7 v8 C1 l. [3 c( O1 Qto setup-globals. t! Y5 J! C+ _$ X" t# A9 U
set current-light nobody ;; just for now, since there are no lights yet
/ d0 t6 s) q( h+ V& J; ~$ i set phase 0
. ~! i' V+ v/ t set num-cars-stopped 05 h9 N' @0 ?. Z
set grid-x-inc world-width / grid-size-x: W1 g4 p" o2 Z' }, I
set grid-y-inc world-height / grid-size-y& L' x2 {4 J- k" ?. U
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary2 [! A/ K Q$ X' [* A- }* i
set acceleration 0.099! B# N6 ^/ g( Z) h: p- W9 y
end& h2 [/ J" h; q3 U0 z; J& K
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 x- U Q- d" \; w& j
;; and initialize the traffic lights to one setting) a$ w' [2 g# ]: Z
to setup-patches
% u* f; P$ Y) e ;; initialize the patch-owned variables and color the patches to a base-color" |7 H8 r; F1 ]6 F/ k! Y5 q! R, y
ask patches
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4 e2 _4 a! | B; \) y set intersection? false2 Y" s- @% W0 o R
set auto? false
9 |; E! ?# d0 q2 J& V5 C set green-light-up? true( s$ [1 Z5 |) I' L
set my-row -18 c4 N" Q- F7 W& {5 {$ `
set my-column -1
3 }7 ]- O! D& @7 v) ]. f set my-phase -1
3 u( C f# c: O. P6 i% W set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets3 l( V3 C" J t1 {- I
set roads patches with
7 ?6 S) ~6 x- f: n8 P* E: ^ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: \, G' [2 s- b! ]1 o! d
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' I; ]7 r2 b' |1 |0 H set intersections roads with" Z# x+ v0 [3 c: E; ^
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
9 g3 o5 |1 C7 l2 E (floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ a& c1 \. b. |; B7 u) w1 ]
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ask roads [ set pcolor white ]5 h$ S7 p! S5 i/ b4 f
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?. `) r3 x" Y- q! r( Y2 Y* F$ y
set roads patches with; Z" Y7 }, q9 } l. Y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 d+ l6 q' M7 f7 D- [: L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 \& J6 @/ Z+ M g7 W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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