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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! n {8 G& G/ W+ J; Y
netlogo自带的social science--traffic grid这一例子当中,7 U9 c. o5 X( K! d# z7 }& v
globals
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: Y; z* ]) V. N+ G! B' R) U0 m grid-x-inc ;; the amount of patches in between two roads in the x direction
% L; L. C- t" ^) K: P! r' l& F( N grid-y-inc ;; the amount of patches in between two roads in the y direction
9 z7 m8 g& t c acceleration ;; the constant that controls how much a car speeds up or slows down by if
* q- s" m* r, O2 k3 x+ h: R ;; it is to accelerate or decelerate
/ ^5 K/ v) J* j( s8 R phase ;; keeps track of the phase
' n" x& _$ a( a! n& }1 @ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure7 B! w6 q) G0 h- L d/ _3 h$ H9 ?
current-light ;; the currently selected light
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+ H( [* s9 ~: S ;; patch agentsets
O) R4 y5 G2 M5 B intersections ;; agentset containing the patches that are intersections
1 v8 E% T0 |5 p( N roads ;; agentset containing the patches that are roads
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& H' J) b" h' \$ K4 d& C1 N* Gturtles-own
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. I4 z) r$ Q/ j) e+ d speed ;; the speed of the turtle
4 w* w8 b0 S& N3 F up-car? ;; true if the turtle moves downwards and false if it moves to the right( d y) \# W2 J5 A- b
wait-time ;; the amount of time since the last time a turtle has moved
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/ Q. R% ?" J: {8 q% }3 U+ K7 Mpatches-own% M2 o0 ^# ]$ u7 _1 t
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intersection? ;; true if the patch is at the intersection of two roads& ~3 `# @, f$ v0 `1 T0 O* c2 K0 N
green-light-up? ;; true if the green light is above the intersection. otherwise, false.& {/ E/ f: M7 E/ P& v
;; false for a non-intersection patches." E# @& Q4 ?$ z8 \
my-row ;; the row of the intersection counting from the upper left corner of the$ y2 a5 l. i- R/ i/ O
;; world. -1 for non-intersection patches.
7 m0 f, Q9 a$ m* O; q my-column ;; the column of the intersection counting from the upper left corner of the! u9 _8 C5 K" `: A( \" u- s# m. n
;; world. -1 for non-intersection patches.4 s. ^; ?# H# I( j. T/ U8 ]) f4 k! I
my-phase ;; the phase for the intersection. -1 for non-intersection patches.# ]' q; k" j% f* \5 P) Y
auto? ;; whether or not this intersection will switch automatically.+ F8 q/ E1 ~+ b
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
: \: | w3 R( w& J5 a# f* W# U& p. d;; Setup Procedures ;;: j" S0 k( j: y
;;;;;;;;;;;;;;;;;;;;;;/ c; N% d; L" v5 A, C5 D
: j! r# R( D D) I0 G& i. C1 @;; Initialize the display by giving the global and patch variables initial values. t6 [" ]/ `- Q' T
;; Create num-cars of turtles if there are enough road patches for one turtle to1 [0 g7 Q7 G" y4 Q, B5 K
;; be created per road patch. Set up the plots.5 e& s3 F$ \; P0 m0 R& 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 variables
+ i# a4 [* S3 }" }) d8 S2 p setup-patches; d* e8 n4 {; \$ s5 [
make-current one-of intersections
& T' ]- t1 M; i( s# ? label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)& o1 G6 w: p' c6 t# p
[
0 n1 x3 h3 O5 L+ R: @+ E0 f9 K# c user-message (word "There are too many cars for the amount of "4 f; s- ^8 ~3 \. W+ e+ j* L
"road. Either increase the amount of roads "& T1 `# C7 ]& A+ k2 x: @9 k
"by increasing the GRID-SIZE-X or "3 _6 e% G; e) `/ u- X
"GRID-SIZE-Y sliders, or decrease the "7 @6 E( ^, z" b; T z8 i* N: Z+ O9 q M% T
"number of cars by lowering the NUMBER slider.\n"
+ S1 ~; s- E9 p" ]7 p, v o8 [ "The setup has stopped.")4 i3 g: f9 s7 e. w) X
stop
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f" {) A9 H, x4 Y: t ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
% J' H W5 B. N crt num-cars) F& f* n* T2 p7 c2 C7 v }
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setup-cars
& i9 N, K! y" S: `* v set-car-color
) u+ @, }: e6 m& E; W record-data
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) A9 N/ m- A( S) L" A5 a7 I" | ;; give the turtles an initial speed
% C( m# {) ]; \( }3 m- t' s- B ask turtles [ set-car-speed ]
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$ a8 ]4 A. ?% _0 U reset-ticks2 A9 O5 b" y/ h3 A+ b
end
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;; Initialize the global variables to appropriate values
% N. ?$ O9 R8 o; D6 a9 x6 Mto setup-globals
# w1 n/ S2 W3 D- d' _5 \$ | set current-light nobody ;; just for now, since there are no lights yet
# U% [6 b h9 \7 b0 a& k ~2 C set phase 0
; i. T% D) b. m( |; X6 ?6 B set num-cars-stopped 0# i# e$ `: K/ J
set grid-x-inc world-width / grid-size-x4 n$ M; W R1 }- B& T `
set grid-y-inc world-height / grid-size-y6 J( w4 ~; {- x
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
( P1 M1 A' ?, w) F% Z5 c* W$ _ set acceleration 0.099: n w% F) V% b8 E+ R+ H3 A* s
end+ m8 |0 u- A6 Y( t+ f- R, z. q! m
+ L$ q3 v8 R: K$ U;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
3 T2 Q+ H# m5 v;; and initialize the traffic lights to one setting
) f. M4 |) W) K Y: \/ \' _to setup-patches
+ y7 V! H; {0 W( V2 x$ k M ;; initialize the patch-owned variables and color the patches to a base-color4 m7 A1 E) G5 i6 g9 o
ask patches
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set intersection? false
6 K2 O7 j$ j1 H2 Y A% r set auto? false& G* y+ V; l4 w0 v; b; B+ r) U {
set green-light-up? true+ ~( w* x. K; |# j2 ?* V
set my-row -1
' C3 \0 h. A9 g& R% O; H set my-column -1
) W2 [3 O8 `7 q6 H set my-phase -1
. v' k, V8 r& `/ ?' K6 e& O set pcolor brown + 3
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% x0 J6 L" ~6 |) @: Z6 p ;; initialize the global variables that hold patch agentsets3 v# s& B( H/ S0 O
set roads patches with
2 P: P4 K F. b/ i5 B/ {' v& Z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or {5 E% D/ z" p6 u
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]- M; \) Y+ |# G4 `; D$ Y0 N" _5 w
set intersections roads with$ \" R$ u- l" ~. e5 |' m
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
- _' y D1 H: G9 `7 g (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& H5 L5 u$ c. |
; D6 {3 J. T$ H ask roads [ set pcolor white ]3 y( s3 r5 k/ ?% |$ P7 B8 O9 q; O
setup-intersections
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& b7 f! i5 n ?4 [% R6 [1 v其中定义道路的句子,如下所示,是什么意思啊?4 [+ D/ e K3 [% y
set roads patches with' w$ z' f6 Y, p, }4 x
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' M' i- {% z; z6 o0 f! t8 m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
! M: @% ^- _7 @% a$ 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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