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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。7 U" @! [: F6 j* C d. c
netlogo自带的social science--traffic grid这一例子当中,7 R5 d* V9 V% o: u( Q
globals
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; I: E, @+ s5 N4 F grid-x-inc ;; the amount of patches in between two roads in the x direction
; c& i/ g$ P% P4 Q1 p8 Q( f grid-y-inc ;; the amount of patches in between two roads in the y direction9 x+ P- D% Z- u* s
acceleration ;; the constant that controls how much a car speeds up or slows down by if5 C& e2 N+ b' ~7 x# V
;; it is to accelerate or decelerate& E; U. i8 I! S% }
phase ;; keeps track of the phase
( v+ T% N6 d# M* \ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
! S9 ?( ^8 C6 A; B+ _# p# p current-light ;; the currently selected light0 k" r1 [4 u8 P& D
! ?4 k( T E7 B; T E2 e- _. L ;; patch agentsets+ ?. W# ^ Y7 S% c
intersections ;; agentset containing the patches that are intersections
' ^7 x9 K6 g9 q; M2 o: |6 W roads ;; agentset containing the patches that are roads
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turtles-own4 F5 C. ^1 X1 m# o+ p! y
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speed ;; the speed of the turtle' o$ G+ v' M& D. |* ^! L
up-car? ;; true if the turtle moves downwards and false if it moves to the right
. ~( d' A! {) y9 n v: h wait-time ;; the amount of time since the last time a turtle has moved
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2 `1 T0 a/ y8 W7 gpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
' d: P% s( W8 v# w" S* x green-light-up? ;; true if the green light is above the intersection. otherwise, false.( o3 Y' j, c; c
;; false for a non-intersection patches.
# H6 ~' n# I# K$ I5 e7 I my-row ;; the row of the intersection counting from the upper left corner of the
0 h: F& m9 p2 y- g) r- \ ;; world. -1 for non-intersection patches.
, r9 P+ H$ f" s6 Q1 U4 s9 }* s my-column ;; the column of the intersection counting from the upper left corner of the" S* q+ e* X) J- D
;; world. -1 for non-intersection patches.
) I3 T e/ s( l0 l3 h! w9 M5 _6 | my-phase ;; the phase for the intersection. -1 for non-intersection patches.6 s; z8 B+ F. K9 p+ F
auto? ;; whether or not this intersection will switch automatically.
, b0 d1 i* f b( o/ W' J ;; false for non-intersection patches. Z k# I% X* x9 E, C
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;;;;;;;;;;;;;;;;;;;;;;
( d1 V5 W8 u) r B0 i V;; Setup Procedures ;;
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% o% G9 L7 e8 c4 _;; Initialize the display by giving the global and patch variables initial values.$ h# L1 n. c& M* _+ B1 I @
;; Create num-cars of turtles if there are enough road patches for one turtle to+ q! i- T5 e5 M
;; be created per road patch. Set up the plots./ {% L. n' |. u* P$ U/ D
to setup
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7 k: ~5 p( d+ ?0 G setup-globals m# G: h1 Z& S" I% d
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;; First we ask the patches to draw themselves and set up a few variables
' @2 d' k6 I2 J setup-patches2 e" V. a. R; h$ _
make-current one-of intersections5 E: m4 u v# H% J4 G1 V# o
label-current0 a$ c- a- L% q0 h" i. O9 |
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set-default-shape turtles "car"
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if (num-cars > count roads)
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2 n t/ b8 {3 |" [6 y) L user-message (word "There are too many cars for the amount of ": q/ A5 n6 q% G4 |
"road. Either increase the amount of roads "1 j+ V, |; o! r
"by increasing the GRID-SIZE-X or "! P( w& g! O' @4 K# P
"GRID-SIZE-Y sliders, or decrease the "6 J0 W" ~( K! }, }/ p
"number of cars by lowering the NUMBER slider.\n"+ s9 Q# [+ {- V, ]6 \
"The setup has stopped.")' y1 u* w9 O- x& o
stop8 }, G2 B. o S; }5 p) x% [
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color& {! G: y) f! o7 g8 b6 {2 _
crt num-cars: r3 W$ Y* r2 B. L0 Z ?
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setup-cars$ \6 s$ W5 ?) L% F
set-car-color1 M3 ]9 p3 o0 {2 \+ |* [
record-data `! w2 Z7 i2 c1 _
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;; give the turtles an initial speed$ n+ G: C4 W, l# H
ask turtles [ set-car-speed ]7 [- l2 d( B0 k
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reset-ticks+ e+ J1 z% F. a8 g* Z9 j
end
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;; Initialize the global variables to appropriate values
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* x0 V, M* G) M7 f p) w set current-light nobody ;; just for now, since there are no lights yet; {6 v, b% S2 T
set phase 0
+ E2 D n0 m0 y2 ^$ l set num-cars-stopped 0
9 u6 e. z8 N) }3 n2 g set grid-x-inc world-width / grid-size-x8 L1 p0 g/ w7 B+ G7 N
set grid-y-inc world-height / grid-size-y
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2 e* ]) q& u; P/ D2 N1 W/ K ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary! D C3 t1 ]1 W7 S
set acceleration 0.099
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' D4 e- w: m+ ^;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 o; M5 d* D& N, h, w1 Y;; and initialize the traffic lights to one setting
' L: f/ W- b7 v. y( dto setup-patches
; w4 D. e1 [0 R ;; initialize the patch-owned variables and color the patches to a base-color' M4 A, H* B$ j
ask patches' }( _* l+ v% @' k
[
7 u! E7 p7 j3 ]3 K2 W set intersection? false
1 q2 G4 v0 u, L" E5 l set auto? false" k) T U/ K5 a$ o) W
set green-light-up? true* J; P/ d+ _8 H' r
set my-row -1; [" G7 Z+ Q3 C- \3 q
set my-column -1
$ I" b; W3 m+ ` set my-phase -1$ x; H, `# h7 L3 E
set pcolor brown + 3( @ W b* x' h! N
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;; initialize the global variables that hold patch agentsets
! a7 G2 V$ J& v set roads patches with
9 S! E- f6 E0 m ^7 |" l3 i [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* D2 m, i" W* A7 ?' u% G- n, k (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
J9 J% A7 }# F- t! N6 V4 \ set intersections roads with. o0 e6 ~" ~0 [5 f2 K
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and& y8 U% K$ p1 U
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 Q" U. Z+ ]3 f6 S R d
/ R8 U8 r" k# |" @3 [ ask roads [ set pcolor white ]# Z! [5 N. L6 s% l1 j& ^
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?
# `9 E9 w6 V$ R9 D- a; v set roads patches with) B6 F; K4 v" }3 E& ?% e- e
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) l9 F6 m# s( s, A b4 G1 ~% H
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) h- n1 }6 ]0 ]2 N9 x# C5 T! ]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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