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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 J- ]. c( X% f# Q5 |
netlogo自带的social science--traffic grid这一例子当中,! ]" C" `! w/ N& E" e! c& v
globals
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4 u8 u( X$ B$ a6 |; P6 f grid-x-inc ;; the amount of patches in between two roads in the x direction. m" e3 S/ @: ]& W4 Y: i; m
grid-y-inc ;; the amount of patches in between two roads in the y direction- z: N: w$ l; T. o# w. Q
acceleration ;; the constant that controls how much a car speeds up or slows down by if4 f; ?; F, W% M" g+ K& i
;; it is to accelerate or decelerate5 ^ W7 ?: W1 \/ e# x9 M0 K
phase ;; keeps track of the phase
* r6 t3 l9 _8 ^: k, q num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure2 O3 w8 s7 _5 Q0 ~* s0 z8 f
current-light ;; the currently selected light% ~; r1 c5 S% v) z! S
+ N: o# f/ r6 M8 I ;; patch agentsets
7 c! ~- D7 w! Y( V# U1 r" g2 T, b intersections ;; agentset containing the patches that are intersections# J0 Y3 G v, h/ L; r
roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle
; Q0 p2 X$ i; n ~, o( } up-car? ;; true if the turtle moves downwards and false if it moves to the right
4 U0 |7 }9 w- z/ x* ] wait-time ;; the amount of time since the last time a turtle has moved
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patches-own ?. H4 ]3 C1 _' U
[
" e0 Y4 k' S) l5 _. q7 ^ intersection? ;; true if the patch is at the intersection of two roads
' G' V l* A; @* g, ]9 k green-light-up? ;; true if the green light is above the intersection. otherwise, false.$ ]- \9 y# F5 P) p) N8 S7 c; h
;; false for a non-intersection patches. \* v' S b. j5 Y$ ^
my-row ;; the row of the intersection counting from the upper left corner of the& t, b: l9 c2 Q
;; world. -1 for non-intersection patches.' G* J, a$ d- @0 P
my-column ;; the column of the intersection counting from the upper left corner of the
l2 F6 ~9 U4 u ;; world. -1 for non-intersection patches.6 G& F( |1 d% w2 [* N
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
. l+ t9 W. G# U& h5 d4 M auto? ;; whether or not this intersection will switch automatically.( N* C5 a- {) `9 Q2 i- b! h
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;3 \6 ?6 {2 \, G- v
;; Setup Procedures ;;2 T- y, C. W' b, J$ V Z$ c
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.% S% W+ c; `+ X7 @
;; Create num-cars of turtles if there are enough road patches for one turtle to
" E) c8 _: q2 L/ R;; be created per road patch. Set up the plots.% q j& u8 r# r8 k. }- n, d, }
to setup
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setup-globals" F" ~; F' X& A6 x! c
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;; First we ask the patches to draw themselves and set up a few variables
" _8 _9 F% |0 b& h setup-patches
: Q+ z$ `; g6 [) b/ M make-current one-of intersections
$ c, t) M* ]+ g label-current' e$ K8 |8 L$ F, _( W# {
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set-default-shape turtles "car"; r7 X" z* k3 B. T
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
! ^" [. n0 T% O! Z "road. Either increase the amount of roads "
- K7 g7 P/ u: z; s) S& Z- k8 U "by increasing the GRID-SIZE-X or "7 p6 T% `) U6 h/ F: G2 {4 b% q# o
"GRID-SIZE-Y sliders, or decrease the "
( [4 t+ ?* N. W& X. C1 b "number of cars by lowering the NUMBER slider.\n"7 a; y& [; w/ ]' J
"The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
7 s7 `, I6 @! ^. x6 ` crt num-cars
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( [+ J* F0 J' \1 l. c- G1 S setup-cars+ P( m" ?2 }/ [) u1 e" Y# [
set-car-color/ D9 E( ~* n* j; v& s: O5 ^$ M
record-data% G0 O/ ], G2 b# z4 G+ m* C
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5 g# ]' d* Q% |6 z7 |1 n. B ;; give the turtles an initial speed
3 o7 ^% w$ L! E- ?, u ask turtles [ set-car-speed ]
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+ a& B1 V0 X7 I reset-ticks
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% P/ W+ Y1 {# z G% _8 k;; Initialize the global variables to appropriate values
3 H; d* G! D4 d- o& E9 Hto setup-globals1 k: Z9 ]9 s+ h
set current-light nobody ;; just for now, since there are no lights yet5 G& m5 R8 Z8 b
set phase 0) D F: h& o& I# q: V$ L
set num-cars-stopped 0; }% G4 l! ?2 B7 s8 L. `0 a
set grid-x-inc world-width / grid-size-x
( u0 [5 e* e9 ` set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
' A5 N; g8 f( I% I set acceleration 0.0993 r' |1 p$ u) @3 l2 w3 V: w( I$ ]
end6 [1 ]0 m- R% W8 O
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,7 r/ V+ E1 f5 _( }8 m
;; and initialize the traffic lights to one setting
3 Y! n3 J9 x- n/ U) r! yto setup-patches
5 _" {& f, n- P ;; initialize the patch-owned variables and color the patches to a base-color
( X8 j4 h8 s: ^4 J# U! A5 F/ c' g ask patches
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set intersection? false; C* A S% j3 D
set auto? false/ Z+ y* W4 U* P
set green-light-up? true; I6 M/ r7 h7 S8 C( }' @2 y
set my-row -1
$ i" ?: @$ w1 c' u7 N$ {5 R set my-column -1
9 j8 n/ [4 D( s1 o# ~ set my-phase -1
% k* R4 X/ `1 { X set pcolor brown + 3
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. N3 m9 o1 O B" u2 l' n$ f ;; initialize the global variables that hold patch agentsets
% D R2 d% W" [9 `, C8 \0 | set roads patches with
" i5 ^6 h2 c5 W3 k# W; m/ Q5 W [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; N2 ?! ]4 ]& G* a+ L" M
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 q2 l9 V# M8 _
set intersections roads with. x. I, f! q; g* [
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and! X) a8 N" B5 @& l T5 [! V1 [ t
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?8 d7 R+ u7 w$ {9 s5 E
set roads patches with
- c6 ~9 J5 t! N5 o) w) ~ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 I; j+ D. n/ O (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 L' O7 l) y b% p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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