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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。& J# p. c# U* f* v" t
netlogo自带的social science--traffic grid这一例子当中,
5 W0 w- w+ T' K$ U ^; S4 e; F" k3 Fglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction3 L# P+ D+ g* k1 s9 W; d+ K6 \
grid-y-inc ;; the amount of patches in between two roads in the y direction
& s7 Q* S* y7 V1 l* \3 O acceleration ;; the constant that controls how much a car speeds up or slows down by if v4 ^- c0 M& n; _* Y% U
;; it is to accelerate or decelerate
+ g6 d4 F/ h { phase ;; keeps track of the phase5 V4 n1 e/ I6 Q- R
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure* a. O- V" Y* A p
current-light ;; the currently selected light
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8 g+ h1 r4 O+ O: R9 |" ~% W$ d! U ;; patch agentsets
+ P I! C4 l8 U intersections ;; agentset containing the patches that are intersections
- J: P" I6 x0 H1 K' f roads ;; agentset containing the patches that are roads
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) P' u m, H x$ \! _turtles-own2 x( O! K& y* I: F9 L
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speed ;; the speed of the turtle, Q- w1 r& t0 M \1 F- C0 j
up-car? ;; true if the turtle moves downwards and false if it moves to the right7 n0 ?, \" H; W2 }- A2 w2 m
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own9 E8 ?& ?- [% X2 L
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intersection? ;; true if the patch is at the intersection of two roads( N U u8 h9 F
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
; M4 ]2 }7 b5 ]3 J ;; false for a non-intersection patches.
6 a$ ^4 y# G& d0 Y6 p0 b+ k my-row ;; the row of the intersection counting from the upper left corner of the1 N# k J) j- f L& E
;; world. -1 for non-intersection patches.- ]) m5 _, `3 @/ z5 ^ |
my-column ;; the column of the intersection counting from the upper left corner of the- R4 r; b8 E" G1 m& d5 i7 R
;; world. -1 for non-intersection patches., y4 J* o1 R2 ]" u
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
6 Y% q( U# l k1 z! G" m* A auto? ;; whether or not this intersection will switch automatically.
% w$ t: D/ _% `7 T: s& C `- N ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;. u [& B) Z$ f- M6 O0 f
;; Setup Procedures ;;
4 l; l: i, i2 k;;;;;;;;;;;;;;;;;;;;;;3 K2 E, Z6 @& c! |8 r
3 j3 Y6 ~0 q, f ^4 n;; Initialize the display by giving the global and patch variables initial values.
8 e% f% |0 i, E8 ?: h;; Create num-cars of turtles if there are enough road patches for one turtle to
/ n$ g% j% u/ m- T% e& R ]5 a# g;; be created per road patch. Set up the plots.
1 S& c/ g* T) E9 w; @" V- wto setup" ^( T' Y/ h: [. S% a* X+ ]$ r
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
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make-current one-of intersections# e$ l8 V9 b% T8 ^- p
label-current
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! G9 _; ^- ?: Z) {% p) I. H6 s set-default-shape turtles "car"
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if (num-cars > count roads)8 ^$ E1 r, B/ A# X6 d4 z
[
/ M1 [$ @: G! J/ |. K user-message (word "There are too many cars for the amount of "
; R3 K" w4 N9 {2 J d9 G! p "road. Either increase the amount of roads "( H6 b5 g8 V/ }7 z% C6 R& q# n6 b5 c, C
"by increasing the GRID-SIZE-X or "
6 h5 C# k, u5 J$ X$ a8 Y4 w "GRID-SIZE-Y sliders, or decrease the "# L0 t7 t# |2 `; ]6 w0 n4 x# S
"number of cars by lowering the NUMBER slider.\n"& T6 f# J/ u7 Y& q2 F9 B4 w
"The setup has stopped.")
+ [) e2 o, K2 Q! G" r+ m* q stop( k0 F2 W4 ~# K( U* @ B0 c& J
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! ?- b P% a, X* w: b ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# S3 p% A/ C- O crt num-cars
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9 U* ~6 M9 [% h setup-cars
7 b6 T+ q+ X' f9 J$ I8 @ set-car-color t# E, w% o( T' a+ u8 Y; T7 K
record-data
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. K5 C- s: M4 k8 ` ;; give the turtles an initial speed
( f: e" c% F2 ]% l5 V I, r ask turtles [ set-car-speed ]" ?% h" c- M: o3 } P f/ I) L
7 q/ ^1 C2 K' r/ w reset-ticks! l) m: a4 @5 J+ M j5 d4 w
end" x9 O5 V# r2 m
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
4 }+ Y+ Q- j+ `% d5 j set phase 08 v, M: r: }# n% C4 C9 T8 B
set num-cars-stopped 0: N$ ]: f4 }2 A: [0 ]
set grid-x-inc world-width / grid-size-x$ { y0 i$ n/ E/ ~0 D
set grid-y-inc world-height / grid-size-y% N6 u e8 b5 n4 V% @( J( Z
0 S4 ?+ U! B& W- m& e3 e& {6 T ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
' K. D0 Q( e4 K: ]* f set acceleration 0.0996 Z: h! p- b/ S; U4 _
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,# f9 o$ \2 }) }- G* n
;; and initialize the traffic lights to one setting
6 W6 r/ A: Q k- O+ q( vto setup-patches
; c3 L) f; D* A1 { y ;; initialize the patch-owned variables and color the patches to a base-color
# p5 s( I" A$ b# m ask patches
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5 P# R3 b/ i( S6 n; C/ e set intersection? false" l3 }2 t% Z& u) ?
set auto? false: Q; I! e) ^& n5 |/ V
set green-light-up? true
V% Z, Z T( }' U set my-row -1, f, n; ~9 t& B s/ `; S# g1 ~
set my-column -1
* o! N$ P; l9 S( `% R) T set my-phase -1 `' I3 W, A. J6 n/ v. H
set pcolor brown + 38 c. z1 t& u. r. p
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;; initialize the global variables that hold patch agentsets& T* ]! m: V5 {5 g
set roads patches with
, t5 U6 v" v+ c- Z" m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" Y! t, Y: b: J% ]6 w X (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; A2 @. {4 [4 j; ? set intersections roads with7 y) U+ t2 s% p: f+ K4 P4 t
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and, A) U) R5 r' H. X& x
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], t6 U3 e3 [1 C2 a: {1 I
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ask roads [ set pcolor white ]' d/ w9 a- ~7 Z( B$ C" D- K
setup-intersections' b! p4 C2 @! ?2 O
end
1 O! t U- b+ _) f7 i/ I其中定义道路的句子,如下所示,是什么意思啊?: S* O( A2 v- [+ p: ^# W
set roads patches with. w6 f) g/ E( b* H7 f( g$ `
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! ~& S4 \. H' W; B0 h
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; i% y: x5 y5 o, O0 r7 a; l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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