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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。4 P8 Y% b1 Y3 \0 g
netlogo自带的social science--traffic grid这一例子当中,
, m2 B( k5 T& q2 Kglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction6 ~4 n9 k- |" O1 N" [
grid-y-inc ;; the amount of patches in between two roads in the y direction3 x6 ~" E7 o1 V1 c; M4 U' z0 x
acceleration ;; the constant that controls how much a car speeds up or slows down by if5 N6 t6 \' g$ ~5 q5 T" M6 Y9 o
;; it is to accelerate or decelerate. m. s" c' p0 s* q) ]8 i; W
phase ;; keeps track of the phase
j6 y* V' \6 e$ k. _ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
+ ~! x, P0 T8 k' { current-light ;; the currently selected light8 i9 ~4 K" s( O+ c' T: ]
+ q) `6 t2 k0 b/ @, ~( z) r ;; patch agentsets
" s% h# n3 e$ G7 x2 p& c; h) r intersections ;; agentset containing the patches that are intersections
6 C6 |; h0 S4 m- o0 l% M4 q roads ;; agentset containing the patches that are roads
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turtles-own2 ?5 k' [* v2 ^9 ?4 C! L
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speed ;; the speed of the turtle0 B9 v6 v% a* }+ d d6 A
up-car? ;; true if the turtle moves downwards and false if it moves to the right# c4 q, ?0 D* Z2 h% { _
wait-time ;; the amount of time since the last time a turtle has moved- K& ]4 e n" u) p$ j/ M+ f0 ?
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( s k7 P/ X a8 C/ Apatches-own0 p' i9 S2 F; E1 D3 V/ @9 {5 I* A
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intersection? ;; true if the patch is at the intersection of two roads, n- L R* B! U7 h' [) E
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
% U7 c( H- M! B% X ;; false for a non-intersection patches.
! q1 {/ h8 ~+ V my-row ;; the row of the intersection counting from the upper left corner of the
. x3 G7 U6 k4 | ;; world. -1 for non-intersection patches.
- x7 x" h/ A. Q! a: _ my-column ;; the column of the intersection counting from the upper left corner of the
. j1 G6 i" E$ l \/ ? ;; world. -1 for non-intersection patches.; ~( `5 Z1 W9 V) K& |) f6 G
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
! b. }+ ?' |0 {/ j: s auto? ;; whether or not this intersection will switch automatically.9 r1 q, |: v# H% b4 I: `4 G
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
4 j& L& r0 T/ e M;; Setup Procedures ;;
( q; k, j3 ?6 L+ R: U;;;;;;;;;;;;;;;;;;;;;;. H2 q e/ X' l* R' i( f
% Q. a; n4 E7 s+ v. [" a+ ?, C4 x;; Initialize the display by giving the global and patch variables initial values.5 w: G. u9 D) B# z4 G
;; Create num-cars of turtles if there are enough road patches for one turtle to
6 x- \6 c; Q6 L8 n+ {% t: ^;; be created per road patch. Set up the plots.
# Y, w( @7 d! sto setup
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, W; Z4 I, x7 |7 b; K setup-globals
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;; First we ask the patches to draw themselves and set up a few variables) q. N) F$ r% d. o* j, W
setup-patches$ B2 A; T A5 i r
make-current one-of intersections& L) Q. Z3 O) d( k7 d
label-current- c% {/ m: \5 V+ B9 m2 A$ G9 _
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set-default-shape turtles "car"
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9 M+ i4 z1 h3 d7 _ if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of " d+ p. [8 o5 B# s( Z: O
"road. Either increase the amount of roads ": A" ^3 U% m7 G4 u) ?! ^9 B5 T' @' E
"by increasing the GRID-SIZE-X or ") t9 t$ n5 x3 `3 K: P+ ] V
"GRID-SIZE-Y sliders, or decrease the "
( z+ v9 \; I7 P$ I6 H3 k "number of cars by lowering the NUMBER slider.\n") A1 i# r. ~. {) g8 ^$ g6 {
"The setup has stopped.")
4 ?$ p8 @# g% M& E. d+ P4 b- f4 }/ o stop" j- D7 O. N0 X9 O, @
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color4 M5 s# r' H5 I8 g$ w! ]
crt num-cars2 `! W |4 B6 R
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setup-cars6 Y' O6 K; C9 M
set-car-color7 U. Q! x3 |# n' j- ^: b4 a
record-data
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( |' ?+ `6 z( P I" D. j ;; give the turtles an initial speed
8 M0 P5 y3 R7 c2 m+ N5 Z ask turtles [ set-car-speed ]
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reset-ticks8 ~; i8 T1 R# L$ R2 S6 L
end7 u0 b6 [3 O' @! f5 R+ B' a9 n
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;; Initialize the global variables to appropriate values8 j" A( _$ D9 w- x
to setup-globals
7 N/ _; X- G) D1 p" b set current-light nobody ;; just for now, since there are no lights yet
+ j2 ?; k3 q7 S: k" a" A set phase 0
7 T4 z# r0 |7 w& c set num-cars-stopped 0
& h `: {3 r1 y4 \6 G set grid-x-inc world-width / grid-size-x: r! c. ]" n; n, U7 u. v7 [3 ~: {0 x! m
set grid-y-inc world-height / grid-size-y/ X6 l( j, D Y6 r
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
! L- ]' C1 T* |$ \ set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 m1 x; B$ G0 E9 N9 z
;; and initialize the traffic lights to one setting
# M2 [. q/ ]0 i# Q/ v/ N2 Nto setup-patches" K4 I5 o# p* k; e! g+ K/ t
;; initialize the patch-owned variables and color the patches to a base-color
( \# \5 ^$ y4 D( A4 c ask patches" h9 o% `/ P- h% ^# `( t0 O
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& h$ p6 K% E) j set intersection? false
. f: F; ~" X# f' A, u5 p! x set auto? false1 E9 d) f) T5 f; ^& Z
set green-light-up? true* F/ B1 n! ^5 b
set my-row -11 p* e: F p8 M
set my-column -1
! _( [" r$ [" ?$ L( T set my-phase -18 F! C9 R; U! n- p% K; C
set pcolor brown + 36 F8 [$ P; |' c: T+ r1 c' ~
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" Q; L, u" k: U ;; initialize the global variables that hold patch agentsets5 _5 Z3 [, \ W1 [
set roads patches with+ \9 U. R' w8 g, |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- v/ X$ m6 T1 C/ i2 y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- r! F! V+ W- O" ` set intersections roads with# M5 E( Y( j1 j
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
7 D A, R0 ?/ o4 n, W+ t (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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( K# ?3 O+ l' n* d( ~7 P3 M2 o ask roads [ set pcolor white ]
& @5 R9 a$ A5 s' ^4 ^5 o3 @; B setup-intersections
" H( J" H4 o. |. Q. R7 Uend* l2 |' a* X3 Z% U/ I: B
其中定义道路的句子,如下所示,是什么意思啊?
: j& ^1 y8 W& I" e# ^0 ^8 A* n* k set roads patches with
* P4 ?, B& W/ `3 ]1 h2 f ~* f1 Q# b [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 d( U5 _1 V+ j (floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ X2 ]/ N$ N4 B" H4 h; j" X; p6 K
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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